此版本包含 GitHub 上虚幻引擎开发者社区提交的 79 项改进！特此对虚幻引擎 4.15 版本的每位贡献者表达诚挚谢意：

20tab srl (20tab)、Andreas Schultes (andreasschultes)、AndrewMAlvarez、Andrzej K. Haczewski (ahaczewski)、Artem V. Navrotskiy (bozaro)、BhaaLseN、Black Phoenix (PhoenixBlack)、Brett Kercher (BrettKercher)、Brian Harris (BrianHarris)、BrodyHiggerson、CA-ADuran、Céleste (CelPlays)、Chris Robertson (CJRobertson)、Christopher P. Yarger (cpyarger)、Deborggraeve Randy (DeborggraeveR)、Deniz Piri (DenizPiri)、Dennis Theisen (Soleone)、Derek van Vliet (derekvanvliet)、Dorgon Chang (dorgonman)、Dustin Biser (dustin-biser)、dyf303、EricLeeFriedman、finap、Garrett (RoyAwesome)、Hannah Gamiel (hgamiel)、How2Compute、Hyeon-Cheol Cho (crocuis)、Jacob Shaffer (Phyllostachys)、Joel McGinnis (joelmcginnis)、Jordan Hueckstaedt (assumptionsoup)、Jørgen P. Tjernø (jorgenpt)、Jukka Jylänki、Justin Graham (mannewalis)、kallehamalainen、kayosiii、Kory Postma (korypostma)、Marat Radchenko (slonopotamus)、Marco Antonio Alvarez (surakin)、Mario Zechner (badlogic)、Markus Breyer (pluranium)、Martin Mittring (MartinMittringAtOculus)、Max Shawabkeh (max99x)、Michael Atkins、Moritz Wundke (moritz-wundke)、Nako Sung (nakosung)、Nathan Sizemore (nathansizemore)、Nathan Stocks (CleanCut)、nero81af、Nicolas Roblin、Orfeas Eleftheriou (orfeasel)、Piotr Bąk (Pierdek)、PjotrSvetachov、poiyomi、projectgheist、rarihoma、Rex Feany (laeos)、Robert Segal (robertfsegal)、Rūdolfs Bundulis (rubu)、Satheesh (ryanjon2040)、Sébastien Rombauts (SRombauts)、stefanzimecki、Stephen Dawkins (elFarto)、Thomas Mayer (tommybear)、Thomas McVay (ThomasMcVay)、tmiv、Yours3lf、Zerophase

新增内容

虚幻引擎 4.15 显著提升了整体稳定性，改进了开发者工作流程并提高了运行时性能，以实现更高效的开发和卓越的最终用户体验。

程序员的编译时间大幅缩短 - 多达 50%！此版本支持在虚幻编辑器运行的同时重新加载内容，在材质编辑器中添加重路由节点，新增了混合空间编辑器（Blendspace Editor）和数学蓝图节点，以及众多其他功能，有助于实现更精简的开发流程。

对于那些想要充分挖掘性能提升空间的人来说，蓝图转 C++ 本机代码（Cooking Blueprints to C++）试验性功能的正式交付、纹理流（Texture Streaming）系统的全面改进和面向 NVIDIA SLI 的交替帧渲染（Alternate Frame Rendering）都能够给高端系统带来大幅的性能提升。

电影（Cinematics）和动画（Animation）流程得到进一步强化，现已支持在 Sequencer 中进行动画混合，将动画曲线（Animation Curves）链接到骨骼以便于 LOD 中的剔除操作，以及利用修改曲线（Modify Curve）节点修改动画蓝图（Animation Blueprints）中的曲线。关卡序列（Level Sequences）现在可以内嵌到 Actor 蓝图（Actor Blueprints）中，而且提供了对关卡序列组件（Level Sequence Components）的早期支持以方便早期使用者。

作为平台改进的一部分，我们提供了 Nintendo Switch 开发（Developing for Nintendo Switch）这一试验性功能。现在可以使用新的定位服务（Location Services）访问 iOS 和 Android 系统上的 GPS 数据。iOS 系统上的流式音频和远程通知得到完全支持。为移动 VR 平台提供了单视场远场渲染（Monoscopic Far Field Rendering）选项，将 HDR 显示输出（HDR display output）作为试验性特性提供，并添加了对 Playstation VR 瞄准控制器（Playstation VR Aim Controllers）的支持。

主要功能

新鲜出炉：Nintendo Switch 支持

我们已经与 Nintendo 合作，帮助虚幻引擎 4 开发者将其游戏移植到 Nintendo Switch！

我们添加了对 Nintendo Switch 游戏机平台的早期游戏开发支持。在此版本中，它仍然是作为一项试验性功能提供。我们计划在下一个版本中将它正式交付。

新鲜出炉：基于物理的默认后处理设置

默认的色调贴图器现在能提供更加电影化的色彩和色调响应！

现在默认启用与学院色彩编码系统（ACES） 匹配的电影色调贴图器。此色调贴图器还能够让引擎适配多种显示类型，包括 HDR 显示。高光设置已经得到更新，在缺省条件下能够提供更符合物理规律的结果。

电影色调贴图器与引擎早期版本的色调贴图器在呈现方面会有差异。您可以在项目的 DefaultEngine.ini 文件的系统设置（SystemSettings）部分添加“r.TonemapperFilm=0”来切换回早期的色调贴图器。我们打算在将来的某个引擎版本中把这个旧的色调贴图器移除。

新鲜出炉：纹理流改进

经过优化的纹理流（Texture Streaming）系统能够减少 CPU 和内存占用并缩短加载时间，同时还能消除低分辨率的失真和自动处理不同平台对内存预算变化的限制。

• 纹理内存占用改善 - 纹理流系统现在基于组件可见性进行处理并以（更小的）材质边框进行静态几何体运算，借此可以减少多达 40% 的纹理内存占用。

• 纹理加载时间改善 - 纹理加载速度提高到原先的 2 至 3 倍，这是通过跟踪可见的 MIP 实现的，这样可以让流转化器聚焦于可见的纹理，然后执行预取数据和强制加载数据的操作。

• CPU 处理时间缩短

  • 通过将动态组件处理和其他任务转移到异步纹理流任务，使它们能够与其他游戏线程任务得到并行的处理，游戏线程更新时间缩短了 50%。

  • 采用了这种分摊处理方法后，流式关卡纹理处理延迟减少了 98%。

• 低分辨率失真减少 - 网格 UV 密度现在基于材质而不是基于网格进行计算，而且会算入 LOD。纹理流现在也支持更广泛的组件类型，包括粒子系统（Particle Systems）和实例化静态网格（Instanced Static Meshes）。

• 自动内存预算 - 纹理流系统现在可以根据内存预算的变化自动调整其行为，无需手动调整。系统会利用各种启发式算法选择需要减少的纹理以维持视觉质量。

新鲜出炉：蓝图转 C++

将蓝图打包成本地源代码以减少执行蓝图的开销这一功能现已正式交付！

这项功能一直作为试验性功能提供，但是我们已经成功地将它应用到了一些自己的项目，例如 《Robo Recall》，所以现在将其作为正式功能交付。

您可以针对个别蓝图执行专项本地源代码转化，也可对所有的蓝图资产执行全面本地源代码转化。在部分平台上对大型项目采用全面（Inclusive）转化模式时可能会遇到可执行文件大小受限的问题；对于很多项目来说，最佳做法是仅针对严重影响性能的蓝图采用专项（Exclusive）转化模式。如需更多信息，请参见蓝图本机化文档。

新鲜出炉：C++ 编译速度提升

虚幻引擎 4 代码库现在的编译速度提升了 50%！头文件只包含其所需的其他标头，而不是每个包含大型单体标头（例如 Engine.h 和 UnrealEd.h）的源文件 - 我们将这一做法称为含您所用（IWYU）。

新模型的约定如下：

• 每个标头现在包含编译所需的一切 - 有个名为 CoreMinimal.h 的标头包含一组内核中普遍存在的属性类型（例如 FString、FName、TArray 和 FVector，等等），现在此标头将首次包含于大部分头文件。

• 每个 .cpp 文件首先包含与其匹配的 .h 文件 - 这有助于验证每个标头是否包含所需的一切东西。虚幻构建工具（UnrealBuildTool）会检查源文件是否遵守这一约定。

• 任何引擎代码都不再包含 Engine.h 或 UnrealEd.h 之类的单体标头 - 尝试从引擎中加进其中一类标头时将会收到警告。为了保持与游戏项目的兼容性，它们仍然存留在引擎中，但包含于引擎时不会产生警告。

• 引擎代码不再明确地包含预编译头文件 - 虽然我们仍然会使用 PCH，但是它们是由虚幻构建工具（UnrealBuildTool）强制加进编译器命令行的。这样我们便可以在不破坏任何现有依赖关系的情况下调整它们所包含的内容。

注：您可以在 *.build.cs 文件（或 BuildConfiguration.xml 全局文件）中设置“bEnforceIWYU = false”来禁用违反这些规则的警告或报错。

新鲜出炉：UI 模糊矩形

您现在可以使用新的“背景模糊”（Background Blur）小部件在 UMG 中对其他 UI 和 3D 场景进行模糊处理！“背景模糊”（Background Blur）小部件还配有内容槽，可用于添加不受模糊处理影响的小部件。

背景内容的模糊度由一个强度值定义，范围是 0（关闭） 到 100（最大强度）。您可以动态地修改模糊度。

强度 = 2	强度 = 10	强度 = 50

新鲜出炉：材质编辑器重路由节点

材质编辑器中现在提供了重路由节点，它可以让您更好地组织材质图！它们在蓝图和材质编辑器中的功能相同而且是纯视觉的，所以应该不会影响您的材质的最终指令计数。

向材质编辑器中添加重路由节点的方法：

• 在“实用程序（Utility）”下方的“材质选用板（Material Palette）”中，将添加重路由节点（Add Reroute Node）拖到图中。

• 双击一根连接样条以插入新的内联重路由节点。

新鲜出炉：Sequencer 动画混合

Sequencer 现在支持多个动画之间的加权混合，让您能够在现有动画的基础上创建复杂的动画序列。您可以在任何时间对任意数量的动画进行混合，包括附加的（局部空间（Local Space））动画。

Sequencer 动画混合

您可以扩展动画轨道并在时间轴上键入所需的值来控制该动画的权重。对于全身动画，引擎会对权重进行规范化以免网格过疏或过密。对于附加动画，使用的是未作修改的指定权重值。

如果您想让骨骼网格使用多种姿势进行动画混合，可以使用新的阿尔法多混（Blend Multi by Alpha）节点将其添加到该网格的动画蓝图（Animation Blueprint）的动画图（Anim Graph）。您可以从上下文菜单中添加新的姿势。

新鲜出炉：Sequencer 动画内嵌到蓝图（试验性）

新的 Actor Sequence 插件（添加了一个 Actor Sequence 组件）支持将序列内嵌到 Actor 蓝图中！这样可以实现序列的复用，具体做法是将动画绑定到蓝图实例然后使用事件图（Event Graph）对其进行触发。您也可以将 Actor Sequence 组件添加到全局中的任何 Actor 来为该 Actor 的单一实例添加动画。

Actor 蓝图

Actor 蓝图视口

新鲜出炉：内容热重载（Content Hot-Reloading）（试验性）

新增的内容热重载（Content Hot-Reloading）功能显著地改善了对磁盘软件包实时重载的支持。

有了这项功能，在处理加载的资产时，所有的编辑器内源控制操作都会更稳定。您也可以在“资产操作（Asset Actions）”下找到“重载（Reload）”选项并用它来强制重载磁盘中的资产，这在您未保存对资产所做的更改并想恢复到磁盘上的版本时非常有用。

要启用这一功能，请转至“编辑器首选项（Editor Preferences）”，然后在“试验性（Experimental）”部分的下方启用“内容热重载（Content Hot-Reloading）”。

注：目前，您必须在编辑器打开状态下使用编辑器内源控件来利用热重载内容。这里涉及一些技术方面的问题，我们希望能够在将来予以解决以支持不受任何限制的同步。

新鲜出炉：高动态范围显示输出（试验性）

虚幻引擎 4 现在可以输出至高动态范围 (HDR) 显示以充分利用其特性，例如更高的对比度和更广泛的色域！

这些都是模拟图像，仅用于演示

对 HDR 显示输出的支持已添加到 Windows Direct3D 11（仅限于英伟达）和 Mac Metal 平台。对其他设备的支持将在后续版本中发布或在其加入时通过 GitHub 提供。当前的实现是通过标准的 ACES 变换（外观修改（look modification） -> 渲染参考（reference rendering） -> 输出显示（output display））进行渲染场景的全部处理，目前实现了 1000-nit 和 2000-nit 显示输出的路径。我们将针对设备的变换烘焙到一个查找表，并将后者用作色调映射通道的一部分，该通道包含大多数标准白平衡和色彩梯度控制。由于与 LDR 控制的兼容性较差，在默认情况下，引擎会在 HDR 输出期间禁用电影色调映射曲线。色调映射完成后我们根据需要应用相关的范围调整和编码。

此外，我们还提供了试验性的 LDR UI 构成支持。这项功能会在启用 HDR 输出时自动处理，尝试尽可能密切地匹配 LDR 外观，不过推荐的做法是通过新的控制台变量来略微改善 UI，以避免与相邻的鲜亮主场景对比时给人一种褪色感。

在启动过程中引擎会对 HDR 输出支持进行检测，仅在连接了受支持的显示时才会进行标记。激活全屏模式并启用 HDR 输出时，应用程序将会尝试自动切换到受支持的显示。HDR 输出的切换可以通过新的控制台变量或游戏用户设置（GameUserSettings）来完成，系统将自动选用最适合当前设备的可用输出显示并设置所有必要的标记。

新鲜出炉：移动渲染预览（OpenGL ES 3.1、Metal 和 Vulkan）

您现在可以使用改进的移动预览（Mobile Preview）功能在编辑器的视口中预览高端移动特性。此模式可模拟 iOS Metal、Android OpenGL ES 3.1 和 Android Vulkan 设备可用的功能集。

注：只用通过项目设置启用的设备才会显示在预览平台菜单中。

新鲜出炉：用于蓝图的 Map/Set 容器

现在可以使用 Map 和 Set 变量类型（加上之前提供的 Array 变量类型）将项的集合存储到蓝图中。增设 Map 和 Set 变量类型可以保证所包含的项都是唯一的，没有重复的条目；也没有影响贴图的重复的“键”。在对大型数据集进行频繁的查找时，它们特别有用。

变量类型（Variable Type）控件现在是一个下拉框，您可以从中选择“Single Variable”、“Array”、“Set”或“Map”。选中“Map”时会出现“值”类型第二级下拉菜单。

在 C++ 中声明的 Set 和 Map 变量现在可以向蓝图公开，但是还不支持复制 C++ 或蓝图中的 Map 和 Set 属性。

新鲜出炉：游戏性标记（Gameplay Tag）

我们对游戏性标记进行了多项改进，现在它们是完全受支持的功能！

游戏性标记是采用“Family.Genus.Species”格式或者简单的“IndividualThinga”格式的名称。这些标签会注册在一个中央字典中。使用“.”进行的名称嵌套支持文字标签和所有父标签的匹配项搜索。游戏性标记容器（GameplayTagContainer）是一组标记，也可以用于匹配操作。

标记可以帮助开发人员高效地定义一系列需要使用的名称，而不必手工键入文本。要使用游戏性标记，必须确保它们已经被注册到中央字典。中央字典可以通过新的游戏性标记（Gameplay Tag）项目设置视图进行访问：

如果您启用了“从配置导入标记（Import Tags from Config）”选项，您可以使用编辑器中此页面上的游戏性标记列表（Gameplay Tag List）来添加标记，或者使用标记选择 UI 来添加。为数据添加 Tag 属性后，您可以在蓝图或 C++ 中对它们执行查询并使用它们来改变功能。蓝图游戏标记库（BlueprintGameplayTagLibrary）具备多种有用的功能。

新鲜出炉：色彩梯度控制

我们在后处理（Post Process）设置中添加了全新的色彩梯度（Color Grading）属性控件以提供更直观的体验和更精确的控制。

新控件的亮点包括：

• 每个滑块下面的有色线条指示该滑块影响的颜色通道。

• 对值进行编辑时的滑块精度提高。您还可以在编辑的同时按下 Shift 键以进一步提高精度。

• 新的色环可以同时修改 X、Y 和 Z 通道。色环下面的滑块控制 X、Y 和 Z 通道的幅度。

新鲜出炉：VR 编辑器菜单改进

更新后的 VR 编辑器快捷菜单和圆环菜单拥有新的界面外观并提高了可用性和功能。

用于复制的圆环菜单

单击控制棒或触摸板来调出/退出圆环菜单，用控制棒/触摸板上的指向来选择选项，然后用扳机选定。您也可以使用激光器选择项目，但控制棒/触摸板操作会覆盖激光器操作。

用于旋转的快捷菜单

快捷菜单的调出和退出功能大体相同，但是现在当快捷菜单可见时，激光会被隐藏以减少杂乱感。

新鲜出炉：VR 编辑器数字小键盘

在 VR 编辑器中使用新的数字小键盘 UI 向文本字段中快速输入数字（0-9）、负数和小数类型的值！

VR 编辑器数字小键盘

您可以分别使用扳机按钮、抓取按钮和修改键来选择数字、确定输入和退格。要退出数字小键盘，只需单击场景内的其他位置或单击触摸板/控制棒，就像使用标准的圆环菜单一样。

新鲜出炉：纹理流调试可视化工具

有三个新的视图模式可用，大大方便了您确保纹理流系统在游戏中以最佳状态工作！

• 基本体距离精度（Primitive Distance Accuracy） - 此视图模式显示流转化器计算的距离相比于 GPU 计算的距离的精度。流转化器计算从视点到纹理实例的沿坐标轴的包络框（AABB）的距离。此包络框是在构建过程中通过计算使用该纹理的组件 LOD 截面 AABB 总数来进行计算的。

• 网格 UV 密度精度 - 此视图模式显示流转化器对每个网格应用的 UV 密度的效果。如果 UV 密度有误，对应网格上的纹理便有欠流（模糊）或溢流（浪费内存）的风险。

• 材质纹理比例精度（Material Texture Scales Accuracy） - 材质中使用的部分纹理按其中一个网格 UV 通道的比例值进行取样。纹理流构建尝试计算所使用的纹理坐标和应用于每个取样纹理的比例。这可能会由于多种原因而失败，在此情况下，流转化器会以纹理坐标为 0、比例为 1 的纹理取样假设条件来进行回退。
  由于材质涉及多种纹理取样，此视图模式会显示所有取样纹理的最严重错误（表现为为欠流和溢流）。这两个极值显示在棋盘式图解中：一个显示最严重的过取样，另一个显示最严重的欠取样。您也可以利用“视图模式选项（View Mode Options）”来检查每个纹理。

您现在还可以使用 stat streaming 控制台命令来查看实时的纹理流统计信息。此统计信息查看命令会报告性能、内存占用和纹理流转化器使用的其他指标。在内存部分中，“pool”指的是概念上的内存池，和占用的实际内存无关。“mips” 映射的是目前纹理占用的内存。内存指标按三个主内存池进行分类：Texture、Streaming 和 Wanted。这些内存池的大小显示在每一行的右侧。

新鲜出炉：飞行摇杆和方向盘支持 (Windows)

您可以在 Windows 系统中使用新的原始输入（Raw Input）插件为方向盘、飞行摇杆和其他不受 XInput 支持的设备提供支持！

添加新设备时只需简单地在项目设置中对其进行配置或编辑 DefaultInput.ini。所有的车辆模板和车辆游戏都已经配置为与 Logitech G920 兼容。

新鲜出炉：力反馈组件（Force Feedback Component）

您可以将新的力回馈组件（Force Feedback Component）添加到全局中的 Actor 来创建局部的触觉效果！这些组件的衰减属性用于根据玩家和施力对象之间的距离确定播放力回馈模式时的强度。您可以直接在组件上指定衰减属性，或者在内容浏览器中创建一个力回馈衰减（Force Feedback Attenuation）资产并将它复用于多个组件。力回馈组件（Force Feedback Component）也可以通过蓝图在全局中产生，其原理类似于音频、贴花和粒子发射器。

新鲜出炉：PlayStationⓇVR 瞄准控制器（PlayStationⓇVR Aim Controller）支持

有了对 PlayStationⓇVR 瞄准控制器的支持，PlayStationⓇVR 上的虚幻引擎 4 游戏会让您更加身临其境！

要激活此功能，只需将运动控制器组件（Motion Controller Component）上的“Hand”值改为“Gun”。PlayStationⓇVR 瞄准控制器的按钮映射的是 DualShock 游戏手柄上的相同按钮。

新鲜出炉：数学材质节点

我们增加了一些常用的数学材质节点，它们应该有助于避免为一些常用操作创建材质函数或自定义节点。

带有“快速（Fast）”标记的节点将执行近似的计算而非实际的指令。这可以为更复杂的材质的处理带来可观的性能提升，但存在输入的限制和精度的取舍。

新鲜出炉：前一帧切换（Previous Frame Switch）材质节点

我们添加了前一帧切换（Previous Frame Switch）节点来支持材质中实现的复杂顶点动画以生成正确的运动矢量，进而使它们能够正确地处理临时 AA 和动态模糊。

前一帧切换

材质顶点动画作为单纯的时间函数已经可以在不做任何修改的情况下运行，但是无法处理影响动画的其他变量，例如材质参数。前一帧切换（Previous Frame Switch）功能让美工师能够跟踪这些参数的变化（例如蓝图中参数的变化）以手动解决这个问题。

注意：使用此功能时需要启用顶点变形（Vertex Deformation）中的精确速度（Accurate velocities）。

新鲜出炉：预处理皮肤局部法线（Pre-Skinned Local Normal）材质节点

您现在可以使用预处理皮肤局部法线（Pre-Skinned Local Normal）在应用了局部对齐三平面材质的骨骼网格上实现自动 UV 贴图之类的效果。

此功能是以新的预处理皮肤局部法线（Pre-Skinned Local Normal）材质节点的形式呈现。它的工作原理和预处理皮肤局部位置（Pre-Skinned Local Position）节点类似，但返回的是骨骼网格（Skeletal Meshes）和静态网格（Static Meshes）的局部表面法线。这为更侧重于局部空间网格对齐的效果或高级用例奠定了基础，例如将动态表面数据写入在另一材质中回读的蒙版。

新鲜出炉：MacOS 和 iOS 平台的 Metal 支持改善

我们扩展了对 Metal 的支持以使用 Apple 在 MacOS 10.12 Sierra 和 iOS 10 中添加的许多新 API 和着色器语言功能。

对于 Mac，我们利用与 Apple 合作推出的新的 Metal Tessellation 流程实现了对虚幻引擎铺嵌功能的完全支持。这使以前不可用的位移和全局位置偏移（World Position Offset）功能得以应用到 Mac 平台。更新后的元素样本（Elemental sample）在 Mac Metal 上默认使用铺嵌。

Mac 和 iOS 现在都支持将 Metal Shader Standard 版本指定为项目设置，让开发人员能够选择是否希望采用新的功能或维持完全向后兼容性。启用新的 Metal v1.2 标准可以使所有 Metal 平台像其他 RHI 一样使用像素着色器中的无序访问视图（Unordered Access Views）来生成任意数据。

我们也利用了适当的内置显示功能（例如 Retina iMac）或 Thunderbolt 外接方式对 Mac 上的 HDR 渲染提供试验性支持。启用基于项目的 HDR 设置时，引擎会把 Metal 配置为将渲染结果输出至支持 DCI-P3 色域的 HDR 显示。

Metal 支持现在还包含一个在开发阶段默认启用并独立于 Xcode 运行的内部验证层。这样一来，即使没有安装开发者工具，引擎也能够报告更多关于在 Metal 上运行时遇到的错误的信息，从而有助于调试间歇性的或特定于硬件的问题。对于性能敏感的测试和交付构建，这一层会被自动编译出来。

新鲜出炉：Sequencer 事件轨道有效负载（Event Track Payload）

Sequencer 中的事件现在可以包含数据有效负载，您可以借此使用关于如何对播放序列作出反应的更丰富上下文信息来触发事件。用有效负载触发事件时，必须创建一个用来定义事件参数的结构，然后将其应用到事件的参数结构属性：

事件可以调用函数并根据事件上下文触发自定义事件，前提是所指定的参数结构与目标函数的原型在位元方面兼容。

新鲜出炉：使用 Sequencer 制作动态对象动画

您可以使用蓝图设置 Sequencer 轨道绑定，然后将序列应用到运行时对象！也就是说，您可以为原本匹配该序列的对象之外的对象制作动画。要从序列中提取序列绑定标识符，请使用新的获取序列绑定（GetSequenceBindings）节点。

新鲜出炉：Sequencer UI 改进

Sequencer 提供了一个新的变换键/截面（Transform Keys/Sections）工具，您可以用它来调整当前所选对象的位置或大小。

其他改进：

• 现在可以将轨道复制和粘贴到兼容的对象。

• 当您查看驻留在主序列中的某个镜头时，引擎现在会评估整个序列的相对时间。镜头本身可以通过设置“单独评估子序列（Evaluate Sub Sequences in Isolation）”分离出来。

• 组件关键帧（Component keyframing）现在添加了包括自动键（autokey）在内的所有关键帧工具的功能，以便于单独选择关键组件。

• 附加轨道时现在实际上是把 actor 附加到目标，而不会对变换进行匹配。这样可以把附加的内容和相关的变换通过序列连接起来。

新鲜出炉：Sequencer 音频音量/音高（Audio Volume/Pitch）曲线

您现在可以直接在 Sequencer 中控制音频部分的音量和音高，从而方便设计师设置淡入、淡出和其他效果。

新鲜出炉：混合空间编辑器改进

混合空间编辑器拥有新的外观和更佳的工作流程！

• 多种更改样本属性的方式 - 除了拖放样本，我们添加的上下文菜单和选值框还可以用来更改样本值或动画序列。

• 按住 Shift（锁定）预览混合空间 - 您可以通过从不同的角度、按不同的缩放比例等方式来预览网格。我们添加了锁定预览值的功能；您可以通过按住 Shift 键来改变预览值。

• 样本尺寸发生改变时对齐到新的网格 - 当网格划分的数量或其中某根轴的尺寸发生改变时，现有的样本会被对齐到最近的可用网格点 那些找不到有效位置的样本会被标记为无效并绘成红色。

• 拖放操作 - 动画工具资产浏览器（Animation Tools Asset Browser）中的拖放操作验证和预览功能已经得到改进，可以显示样本放置的目标位置以及动画是否可以有效地应用于混合空间。

• 拉伸以适应（Stretch to fit）与拉伸至最大轴（Stretch to Largest Axis） - 由于网格占用的 UI 空间发生了改变，我们添加了拉伸网格以填满布局空间和拉伸网格至最大轴的功能。后者是指将最大轴作为网格的最大宽度或高度。

新鲜出炉：姿势快照

我们添加了在蓝图中捕捉用于 Anim 蓝图的运行时骨骼网格（Skeletal Mesh）姿势的功能！

这可以用于将死亡姿势（模拟布偶效果之后）混合到“站起”动画。您也可以将姿势快照保存到一个变量中以供后续搭配任何骨骼网格组件（Skeletal Mesh Component）使用。

新鲜出炉：质量属性调试

我们添加了与物理对象相关的质心和惯性张量的可视化功能。

要使用质量属性可视化功能，请启用新的显示标记显示（Show） > 高级（Advanced） > 质量属性（Mass Properties）。每根轴的粗细表示沿该轴的惯性力矩大小。

新鲜出炉：链接曲线到骨骼

动画曲线现在可以链接到骨骼（Skeleton）中的特定骨骼以便在改变 LOD 时将曲线与骨骼一起选出。这在设置面部动画时特别有用！此功能还可以与层混合功能联合使用以防止曲线值被错误的层覆盖。

新鲜出炉：修改曲线（Modify Curve）动画节点

您现在可以在动画图（Animation Graph）中使用任意逻辑修改动画曲线以制作更有动感的动画。

添加新的修改曲线（Modify Curve）节点后，您可以在它上面右键单击然后选择想修改的曲线。之后每条曲线上都将出现可以连接逻辑的浮动输入引脚。

新鲜出炉：字体资产改进

您现在可以使用新的字型（Font Face）资产在字体（Font）资产之间共享字体数据以减少内存消耗和提高稳定性！

现在字体数据存储在字型（Font Face）资产中，字体（Font）资产只是对字型（Font Face）资产进行引用。这意味着相同的字体数据可以复用于多个字体资产乃至一个字体（Font）资产内的多种字型。现有的字体（Font）资产的内部字体数据会在加载期间自动升级到嵌入式的字型（Font Face）资产。您可以使用字体编辑器（Font Editor）将这些嵌入式的资产分解成真正的可以编辑和共享的字型（Font Face）资产。

新鲜出炉：Linux ARM64 支持

我们添加了对运行 Linux 的 ARM64 (AArch64) 设备的支持！注意：任何此类设备必须支持桌面 OpenGL 3.2 或更高版本才能运行引擎。

新鲜出炉：面向 NVIDIA SLI 的交替帧渲染（Alternate Frame Rendering）支持

当检测到多个显卡时，引擎现在支持采用 Nvidia SLI 配置的 AFR 渲染以提供卓越的性能。最大的提升在于渲染器可以尽早地复制 GPU 之间的帧间相关性。开发人员将需要结合 NVIDIA 来测试他们的游戏，并在适当的情况下让其自动切换到 AFR。

新鲜出炉：面向移动 VR 的单视场远场渲染（Monoscopic Far Field Rendering）（试验性）

单视场远场渲染可以通过只渲染一次远处的对象来提供大幅的性能提升！

当渲染对象远离摄像机时，其立体差异会减少。在一定的距离，远处对象的立体渲染与常规的单视场渲染会变得难以区分。单视场远场渲染利用了这一点，使用一个剪切面将场景分成两个部分：近场和远场。在剪切面近场一侧的所有对象采用立体渲染，剪切面远场一侧的所有对象只渲染一次，然后合成到近场的结果。

目前仅在移动平台上支持单视场远场渲染。要启用单视场远场渲染，请勾选“项目设置（Project Settings）” -> “渲染（Rendering）” -> “VR”下的复选框。我们目前不支持移动多视角和单视场远场的并用，而且使用单视场远场渲染时需要禁用移动 HDR。

新鲜出炉：移动平台自定义模板

移动设备现在可以在材质后处理中使用“自定义模板（Custom Stencil）”来启用对象的轮廓线，将被遮挡的对象可视化，或实现其他类似的效果。

此功能要求启用移动 HDR（MobileHDR）。要在您的项目中启用这一功能，请转至“项目设置（Project Settings）” -> “渲染（Rendering）” -> “后处理（Postprocessing）”并将“自定义深度模板通道（Custom DepthStencil Pass）”设为“通过模板启用（Enabled with Stencil）”。

新鲜出炉：移动着色器内存节省选项

您现在可以通过禁用移动平台游戏不使用的光照设置来显著减少移动平台着色器置换所导致的内存占用！

“项目设置（Project Settings）” -> “渲染（Rendering）”下提供的以下设置可以用来减少内存占用和减小应用程序软件包大小：

• 禁用“允许静态光照（Allow Static Lighting）”

• 禁用“支持组合式静态和 CSM 阴影（Support Combined Static and CSM Shadowing）”

• 禁用“支持远场阴影（Support Distance Field Shadows）”

• 禁用“支持可移动的定向光（Support Movable Directional Lights）”

• 将“最大的可移动点光源数（Max Movable Point Lights）”设为 “0”。

• 启用“使用共享的可移动点光源着色器（Use Shared Movable Point Light Shaders）”

通过设置标记去除 SunTemple 样本内容不使用的光照设置可以将其 Android 软件包减小 22 MB。

新鲜出炉：Android 图形调试器支持集成

Android 应用程序现在可以在打包时选择支持第三方图形调试器。您可以根据自己设备的 GPU 来选择 Mali Graphics Debugger 或 Adreno Profiler。图形调试器（Graphics Debugger）选项在“项目设置（Project Settings）” -> “Android”下。

您需要先从 GPU 供应商的网站下载和安装这些调试器，而且在进行调试前，每种调试器都需要少量的额外设置来配置您的设备。选择调试器类型后，务必遵循界面上的指示来操作。

还要注意的是，如果您在将应用程序打包时选择支持特定的 GPU 调试器，它可能无法在装有不同 GPU 的设备上正确地运行。

新鲜出炉：基于 GPS 数据的 Android 和 iOS 定位服务

Android 和 iOS 平台现在支持 GPS 数据访问！我们新增了一个“On Location Changed”委托，对应的蓝图节点在“服务（Services）” -> “移动（Mobile）” -> “位置（Location）”下。

新鲜出炉：iOS 流式音频

iOS 平台现在支持流式音频！流式音频可以减少内存占用并缩短关卡加载时间。已经标记为流式的资产在其他平台上也将自动采用流式传输。

新鲜出炉：iOS 远程通知

iOS 平台现在支持远程通知！游戏可以注册回调以处理通知。编辑器提供了为应用程序设置通知的工具。

新鲜出炉：车辆支持（Vehicle Support）移为插件

我们现在将 PhysX 车辆支持（PhysX Vehicle support）重构成了一个可选的插件！这样便于在不使用车辆的游戏中移除此功能以节省磁盘空间和内存。我们还在这项工作中为引擎增加了几个有用的物理扩展点（例如 OnPhysSceneInit/Term 和 OnPhysSceneStep）以方便其他开发人员编写自己的类似系统。

如果您想把老的“轮胎类型（TireType）”资产（引擎中已弃用）迁移到新的“轮胎配置（TireConfig）”资产（在新的 PhysXVehicles 插件中定义），您需要执行一个手动步骤。虚幻引擎 4 编辑器中有一个新的控制台命令可以帮助您完成此操作：您只需调出控制台并输入“ConvertTireTypes”。引擎会新建“轮胎配置（TireConfig）”资产、复制属性并将它们分配给任何车轮（VehicleWheel）蓝图。然后便可以删除老的“轮胎类型（TireType）”资产。

Release Notes

AI

• New: A Cone EQS generator has been added.

• Bugfix: Fixed AI perception system not properly registering perception listeners spawned as part of "begin play" in streamed-in sublevels.

• Bugfix: Fixed a bug in the Env Query Generator Simple Grid resulting in one extra column and row of points being generated.

• Bugfix: A number of fixes to how and when static mesh collision gets applied to navmesh generation process. This makes static mesh collision changes instantly applied to navmesh on the level.

• Bugfix: Pasting nodes in the Behavior Tree editor has been fixed to make pasting location predictable.

• Bugfix: Fixed a bug in EQS debug drawing resulting in item labels not showing.

• Bugfix: Fixed a bug in EQS debug drawing resulting in displaying labels of item that are no longer being debugged.

• Bugfix: Fixed vertical jitter in replicated Nav Walking movement.

• Improvements for using gameplay debugger in Simulate in Editor mode, unified category toggling with input events between simulate and game/play modes.

Behavior Tree

• Bugfix: Fixed the Blackboard component pausing but never being unpaused if we ended up restarting the Behavior Tree instead of continuing.

Debugging Tools

• Bugfix: Fixed gameplay debugger's EQS category skipping timestamps, and improved readability of presented data.

Navigation

• New: Added new component for creating navigation links: Nav Link Component.

• Bugfix: Get Random Point In Navigable Radius has been fixed to not return invalid locations if there's any navmesh within specified radius.

• Bugfix: Fixed a bug in the Nav Link Proxy Point Links' Area Class application that was resulting in the value getting ignored.

Animation

• New: Added experimental support for facial animation.

• New: Anim Blueprint thread safety is now checked in the compiler.

  • Added extra warnings in the Anim Blueprint compiler based around these new keys to help people catch suspect thread usage.

• New: Expanded pose snapshot system.

  • Allows poses to be stored in variables so they can be managed like any other Blueprint data.

  • Added modes to Anim Node Pose Snapshot so that we can either use the named pose or a Pose Snapshot variable pin.

• New: Added editor-only flag Update Animation In Editor and setter function to Skeletal Mesh Components to allow playback of animations on Skeletal Meshes placed in the level.

• Bugfix: Fixed a crash when retargetting animation assets to another skeleton via duplicate and retarget.

• Bugfix: Fixed marker sync crash when animation being played by a sequence node changes while that nodes sync group is not active.

• Bugfix: Fixed 'auto' check box in Morph Target panel.

• Bugfix: Fixed situation in which stale material references could be present as override materials on Static and Skeletal meshes inside of a level.

• Bugfix: Fixed removal of bone tree entries from a Skeleton after performing "Remove Unused Bones" (caused retargeting options to become out of sync).

• Bugfix: Fixed anim blueprint compiler not following reroute nodes when building cached pose fragment list.

• Removed 4.11 deprecated functions from animation systems.

• Removed warning on Least Destructive animation compression (it was incorrectly applied to least destructive due to legacy reasons).

• Added extra information to log warning about using additive animations in Single Node Anim Instance.

• Changed “Ensure All Indices Have Handles” to try and maintain validity of as many of the handles as possible to stop crash when calling “Get Key.”

• Morphtarget applying priority has changed.

  • First, it will apply animation curves to active morphtarget list.

  • Second, it will apply (and override if exists) Set Morph Target curves to active morphtarget list.

  • Set Morph Target can also clear the weight if you decided to not to remove from the list.

Animation Assets

• New: Added the ability to specify per-sample animation rate scales in blendspaces.

• Bugfix: Fixed shadowing issue for Alembic Caches which had incorrect (too small) bounds.

• Bugfix: Fixed popping in On Rep Replicated Anim Montage.

• Made Scrubbing the Play Back Speed property on Geometry Cache components less sensitive.

• Changed behaviour for calculating blendspace grid weighting for one, two or colinear triangles.

  • One: Fill grid weights to single sample.

  • Two: Find closest point on line between the two samples for the grid point, and weight according to the distance on the line.

  • Colinear: Find two closest samples and apply behaviour above.

Animation Blueprint

• New: Added Blend Option (and optional Custom Curve) to Pose Blend Node.

• Bugfix: Fixed anim sub-instances only allowing one pin to work when any pin required a call out to the VM for evaluation.

• Bugfix: Fixed Joint Target Location not being available in the detail panel.

• Exposed various montage functions to Blueprint.

• Added curve panel to anim BP editor.

• Copy-to-array now works with the anim blueprint 'fast path'.

• ‘Blend Two Poses Together Per Bone’ will now blend curves using ‘combine’. Previously it only took curve data from the second pose input.

Import/Export

• Bugfix: Fixed an issue where Matrix Samples would be imported incorrectly for Alembic Caches.

• Changed the way we populate Smoothing Group information for Alembic Caches.

• Refactored the Skeletal LOD workflow. Now we track source files for LODs to save time when reimporting LODs often. It's still possible to pick new files and overwrite the current settings.

Skeletal Mesh

• New: Added support for per-component vertex color overrides for Skeletal Meshes.Nintendo

  • Use the Set Vertex Color Override function (also exposed to Blueprints) to specify a new color buffer to apply.

• Bugfix: Fixed edge cases so Skeletal Mesh Components should now properly scale collisions when simulating, or when using physical animation.

• Bugfix: Fixed bounds not being updated on existing skeletal mesh components when changing physics assets.

• Made sure Set Morph Target still take precedence over Animation Curves for Slave Component.

Tools

• New: Added access to the viewport client from Persona Viewport.

• New: Added "Show Selected and Parents" to bone display options.

• New: Added display/edit of bone transforms in details panel.

• New: Widened bone reference widget to give a better view of the name and added full name to tooltip.

• New: Auto select current bone when opening the skeleton tree on a bone reference.

• New: Newly added virtual bones are now selected in the skeleton tree.

• New: Changed "Reference Pose" option for additive animation ref pose to "Skeleton Reference Pose" to make it clearer that it is not the meshes reference pose being used.

• Bugfix: Fixed crash in thumbnail rendering when creating a new montage.

• Bugfix: Fixed skeleton tree selection disappearing when filtering changes.

• Bugfix: Fixed notify validation not triggering when using set time/set frame context menu options.

• Bugfix: Fixed montage thumbnail rendering using ref pose instead of the actual asset.

• Bugfix: Fixed "number of curves" label on an animation not updating after adding or removing a curve.

• Bugfix: Fixed newly imported animations having black thumbnails.

• Bugfix: Fixed compile error when blend space on aim offset nodes is exposed as pin.

• Bugfix: Fixed scrolling in Pose Asset editor panel.

• Bugfix: Fixed tooltip when dragging animation assets onto animation player nodes.

• Bugfix: Fixed new virtual bones being created off screen.

• Bugfix: Fixed missing mesh when setting preview skeletal meshes in animation editors.

• Current asset is now initially selected in the asset family shortcut bar dropdown.

• Camera is no longer reset when setting skeletal meshes in the skeletal mesh editor (etc.).

  • Focus shortcut (F key) now works in the skeleton tree too.

• Removed FPersona and supporting classes.

  • Please use individual asset editors instead.

• Rezeroing animation is now explicit about what it does (current vs. specified frame).

• Changed slot node category from Blends to Montage.

Audio

• New: Sound Cues can now be played/stopped by clicking a button on the thumbnail.

• New: Added the ability to disable Master Reverb and EQ in Project Settings.

• BugFix: Audio Components no longer override subtitle priority by default.

  • Any existing Audio Component that had changed the priority from the default value will still have bOverrideSubtitlePriority as true, those that had not changed the priority from the default have been set to false.

• BugFix: Fixed a crash that would happen when a Sound Cue Delay node set to 0.0.

• BugFix: Fixed a small memory leak in sound concurrency management.

Automation

• New: Added architecture hash to path for generated includes on Linux Installed Build.

• New: Included .tps files in the installed build.

• New: Changed BuildPlugin command so that it reads from installed platform data to decide which targets to build for more flexible task for BuildGraph. Now takes "From" and "To" attributes, which may take individual files as well as wildcards, and permits renaming as part of copies. The Separate "Files" attribute is still supported, but is now optional, and is used to filter the list of source files.

• • BuildGraph: Added a task, which can move or rename files using the same syntax as the task.

• New: Added support in BuildGraph for multi-line properties, declared inside a tag. Mutli-line properties can be useful for making lists for filtering. Each non-empty line inside the property tag is stripped of leading and trailing whitespace, and appended to the property value separated by a semicolon.

• New: Added architecture hash to path for generated includes on Linux Installed Build.

Blueprints

• New: Making the UI for adding/removing parameters in custom Blueprint functions behave similarly to the struct creation dialog in the Content Browser.

  • The New button is no longer in the bottom right of Inputs and Outputs. Instead, add via the + icon in the Category header.

  • Parameter ordering controls have been moved onto the main parameter row instead of being nested inside the collapse panel.

  • A tooltip will now let you know the full parameter name and type when you hover over the editable name field.

• New: Added RotatorToAxisAndAngle function.

• New: Added aliases for "dot" and "cross" math operations in the Blueprint Math Expression node.

• New: Added support for DataTable members variables in Blueprints.

• BugFix: Fixed a crash on load for Blueprints casting to a ChildActorComponent’s parent.

• BugFix: Fixed a crash when using “Select All Input nodes” option from the Blueprint pin menu.

• BugFix: Fixed a crash which could happen when using reroute nodes in Blueprints.

• BugFix: Fixed a crash when selecting an enum value from a Blueprint node's enum combo box.

• BugFix: Fixed a crash that could happen after receiving a "Graph is linked to object(s) in external map" error message.

• BugFix: Fixed a crash when debugging Blueprints across multiple worlds.

• BugFix: Fix crash in execArray_Append that could occur when one of the target array's UProperties was missing.

• BugFix: Fixed a crash that would sometimes occur when collapsing nodes to a function or macro.

• BugFix: Fixed a rare crash in IsTypeCompatiableWithProperty.

• BugFix: Fixed a crash during bootup involving CDO of nativized Blueprints.

• BugFix: Fixed a stale object crash in HandlePlaceholderScriptRef.

• BugFix: Fixed a crash caused by an object name collision that could occur when loading some older Blueprint assets.

• BugFix: Fixed a that would occur when loading a Blueprint with a collapsed node with a split struct pin.

• BugFix: Fixed a crash  with Undo/Redo commands causing the component and actor selection to become unsynchronized.

• BugFix: Fixed a regression in which nested scene component subobjects would no longer be registered after construction of an instance-added component.

• BugFix: Fixed inaccurate ensure message that could trigger when choosing a bad target from the Blueprint debug menu.

• BugFix: The Vector2D default pin values are now properly saved

• BugFix: Fixed the inability to edit an Instanced Static Mesh Component instance array on Actor instances when the Instanced Static Mesh Component is inherited from a Blueprint class.

• BugFix: An explicit warning is now logged on BuildCookRun or a standalone cook when the -nativizeAssets flag is omitted from the command line for a nativization-enabled project.

• BugFix: Fixed various component instance data loss issues for components added to an Actor through one or more Add Component nodes in a Blueprint graph.

• BugFix: Fixed attached root scene component relative transform values after reconstruction of an Actor-based Blueprint instance.

• BugFix: Fixed a bug that would drop pin connections when ctrl dragging them.

• BugFix: Fixed a bug that would cause Volume Actor Reference nodes to use the wrong class icon.

• BugFix: Fix for breakpoints failing in Level Blueprints when multiple Clients are running in PIE.

• BugFix: Fixed an issue with CreateRenderTarget2D called in construction script during cooking.

• BugFix: Fixed an issue which could cause invalid Blueprint warnings when using a cast node.

• BugFix: Fixed an issue in the struct editor that would prevent you from including spaces in a variable name.

• BugFix: Fixed an issue that could cause a Blueprint compiler warning when using one of the Ease nodes.

• BugFix: Fixed an issue where Blueprints could improperly warn/error about missing variables.

• BugFix: Fixed a bug where Blueprints could improperly error about missing Event Dispatchers.

• BugFix: Fixed a bug that could cause latent Blueprint nodes to lose pin connections when using a split pin.

• BugFix: Fixed an issue where copying variable nodes and pasting them into another graph with a variable of the same name and type would prevent that node from showing up in a reference search.

• BugFix: Fixed an issue where Reroute nodes for variable would not always mirror data properly from the source pin.

• BugFix: Fixed an issue while loading of circularly dependent Blueprints when a user defined struct’s default value was part of the dependency graph.

• BugFix: Dragging and dropping a function into a graph can not be properly undone.

• BugFix: Corrected the behavior of nativized UserDefinedEnums. Sometimes enum names did not match the normal version of the data.

• BugFix: Fixed an issue for "Graph Linked to External Private Object" error when deleting folders via the Content Browser when the folders include Actor Blueprints

• BugFix: Fixed cyclic dependencies with Nativization that occur while native class construction happens.

• BugFix: Fixed a data-loss issue related to non-native Blueprint classes that override inherited component default values from a nativized Blueprint class hierarchy.

• Changed ClearRenderTarget2D default alpha to 1, which is necessary for correct compositing.

• The Graph Editors can now set their grid snap size via the Editor Preferences > Appearance.

• Pre-Populated Blueprint nodes now attach all matching outputs to parent Blueprint calls (not just exec pins).

• The CreateSaveGameObject node now alters its output type based on the SaveGameClass input.

• IntVector can now be used in Blueprints.

• Blueprint Context menu now has improved results for 'sel', 'sele', 'selec', 'bra', and 'foreach'.

• Create Event node now displays the signature of the function that is desired.

• Adding a component in the Blueprint Editor now adds the component as a child of the selected component.

• Blueprint compact nodes no longer have two different looks. Now, all compact nodes have rounded edges and have a matte color.

• GetReflectionVector math function has been exposed to Blueprints.

• Exposed a new function, GetCommandLine, to Blueprints which will return the command line used to launch the process.

• You can now select Blueprint assets for nativization in the Project Settings > Packaging.

• The Blueprint nativization feature will now be automatically enabled for the project when a Blueprint class is marked for nativization in the Blueprint Class settings view.

• Interface class dependencies that are not enabled for nativization will now raise an error at cook time if dependent classes are marked for nativization.

• We now hide 'EditInstanceOnly' properties when viewing/editing SCS component defaults in the Blueprint editor, as this does not apply to an instance context.

Core

• New: Added support for " in FName so they will be converted properly to \" internally.

• New: Removed defunct "USING_SIGNED_CONTENT" define.

• New: All platforms are now compiled with C++14 standard.

• New: Allow enabling sound (-enablesound commandline switch) if the game disabled it by default.

• Bugfix: Fixed a garbage collection crash when copying an empty timeline.

• Bugfix: Module Manager shutdown fixes:

  • Shutdown Module is now called in reverse order to when Startup Module is FINISHED. This allows modules to reference dependencies in their Startup Module to ensure they are loaded, and be sure they will still be around in Shutdown Module.

  • HTTP Module now shuts down in Shutdown Module and not Pre Unload Callback.

  • Added comments to Module headers to indicate this new change in behavior.

  • Removed manual startup of HTTP module in Launch Engine Loop as it's no longer needed. This should save the module from being around if not really used by engine.

• Bugfix: Many fixes to cooking complicated blueprints when s.EventDrivenLoaderEnabled is turned on.

• Bugfix: Fixed a bug on 32-bit targets, some int64s could be aligned to 4 bytes and then passed into platform atomics functions. On apple platforms, those atomics functions can crash when passed in a non-8 byte aligned int64. Some explicit alignment has been added to those variables to 8 bytes.

• Added some validation of the class index in exportmap entries. Stops the engine crashing when corrupt package data is encountered.

• Bugfix: Fixed Cancel Async Loading crashes when EDL was enabled.

• Bugfix: Fixed memory stomps in SSL certificate initialization.

• Bugfix: Fixed wrong reporting of ever increasing STAT_TextureMemory* and STAT_RenderTargetMemory* numbers in memory profiler.

• Changed the Segment Dist To Segment Safe function in  FMath to handle the case where either (or both) of the input segments create points.

• When CVar override is denied, current value of the CVar will be printed in the warning message for clarity.

• Updated Generate Distill File Sets Commandlet so that it resolves string asset references after loading packages, to ensure that it finds all required files.

• Updated Json Object Converter so that, by default, Struct To Json Attributes now skips transient properties.

• Pak signing has been properly integrated with the new event driven loading system.

• Added optimizations to the signature checking system so it is much faster.

• AES encryption can now be configured for use with pak files, and has been integrated with the new event driven loader system.

• bEncryptIniFiles=True can be added to your projects DefaultGame.ini to encrypt all ini files in the pak files.

• Both AES encryption and pak signing are now configured from an Encryption.ini config hierarchy. See Config\DefaultEncryption.ini and Config\Windows\WindowsEncryption.ini in the ShooterGame sample project for an example of how to configure both encryption and pak signing.

• Minor change to how bulk data is async loaded, allowing it to be freed correctly after first copy when requested.

• Added some extra logging information to try and help catch a corrupt archive chunk crash seen in live builds.

• Prevented reinstancing UEngine-derived objects on hot reload as this class is not reinstanceable.

• Enabled full callstacks in non-monolithic builds by default.

• Made Assemble Reference Token Stream thread safe for blueprints loaded on the async loading thread.

• Pak platform file will now only be used if pak files exist regardless of command line params like -pak, -signedpak and -signed.

• It is no longer necessary to rebuild the cooked exe to enable the Event Driven Loader. EDL and the new async IO are now controlled with ini settings only (through Project Settings). EDL can now be enabled in Blueprint only projects and binary distribution of the engine.

• Event Driven Loader is now enabled by default.

Editor and Tools

• New: Added to Sequence Recorder:

  • Optimize record transforms by setting all the keyframes at once.

  • Option to toggle removing redundant keyframes from the recorded tracks. This is on by default.

• New: Improved search for matching Material on FBX mesh import. Added a “Search Location” dropdown in the Material Import Options to control how the search will be performed. When an imported mesh references a Material, the importer will search for a Material with the same name in the assets folders. The search is performed in the following order based on the “Search Location” setting:

  • "Local" option will behave as before with a non recursive search in the destination folder (e.g. in /Game/Content/Assets/MyImportFolder/ only).

  • "Under Parent" option performs a "Local" search first followed by a recursive search from the destination folder and a recursive search from the parent's folder (e.g. in /Game/Content/Assets/MyImportFolder/ and subfolders then in /Game/Content/Assets/ and subfolders).

  • "Under Root" option performs an "Under Parent" search first followed by a recursive search from the root folder (e.g. in /Game/ and subfolders).

  • "All Assets" option performs an "Under Root" search first, followed by a recursive search of every asset folder (e.g. in / and subfolders).

• New: Users are now able to customize the Class Browser/Picker to filter out developer folders as well as hide internal use classes via INI settings.

  • ViewOptions button has been added to enable users to choose whether or not these filters are enabled. By default, internal only classes will be hidden and you will be limited to your own developer folder.

  • Go to Project Settings >Class Viewer >Class Visibility Management to customize the default classes and paths used by the filter.

• New: Added new sorting options for Statistics Window so that it now sort columns based on types and texture dimensions.

• New: You can now export Static Mesh LODs from the editor. This requires that the Static Mesh be in the Level and use the FIle >  Export options.

• New: The Gameplay Tags UI has been improved:

  • In the Project Settings window, Gameplay Tags will show up as a tree instead of as a list.

  • In the treeview, an Add Subtag button has been added to each tag that will add a new subtag in the same INI file.

  • Comments can now be attached to gameplay tags, and will show up in the tooltip for a tag.

  • Each tag has an options drop down menu that allows you to search for references to that tag. In the Project Settings window, the dropdown also has options to delete and rename tags.

  • When creating a new gameplay tag, you can specify what INI file it will be created in.

• New: Added option to import an FBX with front X axis.

• New: The FBX exporter can now export Bone Scale.

• New: It's now possible to shift-drag (Camera follows the object being moved) an object in the Level Viewport and move the 3 axis at the same time (drag the center of the manipulator).

• New: The FBX importer is now able to import LOD groups with the Combine Mesh option enabled.

• New: Added a shortcut for the Merge Actor functionality to right-click Context menu on Actors inside of the Level Viewport.

• New: FBX imports now support using Multi-Sub-Object Materials generated by 3DS Max to prevent importing unused Materials.

• New: FBX now takes into account all scene conversion options that were set at import.

• New: Added support for detail customizations on root structs.

• New: Added the ability to set and retrieve a host tab manager from the details view.

• New: Added the ability to extend default layouts.

• New: Added “Plane” to the Basic Shapes category of the Modes window.

• New: Added the ability to create groups within groups in the Details panel customizations.

• New: Added the ability for struct customizations to add categories to the parent object in the details customization.

• New: Added support in MallocProfiler2 program to use nm.exe to symbolicate callstacks for clang-based platforms that have nm.exe that can look up symbols. It is easy to subclass the base support for each platform.

• BugFix: Fixed a crash when importing Skeletal Mesh FBX file that contain one or more materials or textures with the same name as the FBX filename.

• BugFix: Fixed a crash in the details customizations when the asset picker is used without a property.

• BugFix: Fixed a regression where motion blur was enabled in editor views.

• BugFix: Fixed a crash when importing a FBX with some node containing unused materials.

• BugFix: Fixed a crash on Editor close after VR Foliage editing.

• BugFix: Fixed a crash when using the Editor while Simulating (SIE) with an Actor copied to the clipboard.

  • Affects Mac when navigating the Editor or simply updating the selection to an actor component.

  • Affects Windows when showing a menu containing a Paste option (for example the Edit menu in the main menu).

• BugFix: Fixed a crash in the Curve editors when scaling to fit after resetting the curve to default.

• BugFix: Fixed a crash when importing an FBX that does not contain any mesh.

• BugFix: Fixed a crash when importing a Skeletal Mesh with no Material.

• BugFix: Fixed a crash occurring when trying to merge meshes/actors with their lightmap UV index set to 0.

• BugFix: Fixed a crash in the Texture editor when opening a texture that does not have a valid texture resource.

• BugFix: Fixed the Output Log filter that was not updating when text was committed.

• BugFix: Fixed an issue that prevented skipping of intro movies using the Default Game Movie Player by using a keyboard or gamepad input.

• BugFix: Fixed an issue where the “IDE downloading” would remain open if the Add Code window was closed while the toast was active.

• BugFix: Fixed the functionality to drag a folder and its sub-directories from the OS file system into the Content Browser.

• BugFix: Static Mesh Component’s Overridden Lightmap Resolution previously displayed the value it was set to, even when bOverrideLightMapRes is false. The behavior is to use Lightmap Resolution on the Static Mesh member instead when bOverrideLightMapRes is false. The UI was adjusted to reflect the more accurate behavior.

• BugFix: The Build Settings will now be set properly when reimporting with different options.

• BugFix: FBX Reimport of an asset that originally imported from a file containing multiple objects will reimport only the FBX content that match the selected asset in the Content Browser.

• BugFix: The FBX importer now imports local (parented) and global (non-parented) sockets correctly.

• BugFix: Fixed an issue where AssetPtrs/Asset IDs were not getting properly fixed up when renaming assets in the Editor.

• BugFix: Changed the maximum LOD level for merging actors to 7. Previously this was set to 8, which was invalid.

• BugFix: Material settings are now completely disabled in the Merge Actor tab when Material Merging is disabled.

• BugFix: Fixed a situation in advanced preview scenes where hiding the environment would not apply to reflections.

• BugFix: Fixed shadows being faceted/hardened in advanced preview scenes.

• BugFix: Fixed Material and Vertice count issues with Skeletal and Static Mesh conversions.

• BugFix: Fixed Full Scene Importer changing Actor mobility when reimporting.

• BugFix: Fixed an XML Parser assert when parsing a root tag that completes on the same line.

• BugFix: Fixed hidden black callstack text in the Crash Reporter Client.

• BugFix: Fixed an issue with compressed.ddp not containing all the shaders needed to load up the Editor for the first time.

• BugFix: Fixed an issue when collapsing all, hiding everything in the settings editors.

• BugFix: Fixed stretched Landscape Editor Icons.

• BugFix: Fixed an issue when opening new assets in a minimized window not restoring that window.

• BugFix: Fixed a number of Keybindings problems:

  • Removed editor keybindings from Project Settings. It should not have been in there (already in Editor Preferences).

  • Removed duplicate registration of editor keybindings from Editor Preferences.

  • Fixed memory leak regenerating keybinding widgets when ending PIE world.

  • Cleaned up styling a bit to make keybindings widgets clearer.

• BugFix: Fixed the menus in the Editor not appearing in certain preview builds of Windows 10.

• BugFix: Import Commandlet Fixes:

  • Fixed a crash when the source control could not be contacted.

  • Fixed assets not importing correctly if they depended on other assets in a previous import group within the automated import.

• BugFix: Fixed an issue with UGS with Perforce having a branch root with a lowercase drive letter. UBT Intermediate response files include path names and are case sensitive, so it’s important that they are always consistent. Windows seems to always include a drive letter in uppercase.

• BugFix: Fixed an issue with UGS where editor .target file being deleted when doing a content-only sync, causing a prompt to rebuilt the editor when trying to launch.

• BugFix: Fixed an issue with UGS to ensure the project config file remains valid even if sync is aborted due to files needing resolve. This prevents user configuration from not being applied onto build steps.

• BugFix: Fixed material assignment error when importing multiple mesh with Combine Mesh option enabled in the Import Options.

• BugFix: Fixed an issue where rebuilding geometry for the current level would actually erroneously build dynamic brushes from all levels.

• BugFix: Fixed an issue where UBT was not correctly passing quoted strings as defines to the code build environment for PS4 and Mac targets.

• Reorganized the Post Process settings so they appear as categories in the parent and so that they have better categories to make it clear what all the settings do.

• Added ability to UGS to use Ctrl + A to select all in the log window.

• Added ability to UGS for Perforce Settings window, allowing users to set optional values for tuning Perforce performance on unreliable connections.

• Changed installed plugins to be disabled by default, but display a notification in the editor the first you load a project with a new one. Installed plugins which are new to this project will be adorned with a  “New!” badge in the plugin browser.

• The cost of deleting hundreds of Actors simultaneously has been reduced by reorganizing how we check for Blueprint dependencies on the Actors.

• Some of the plugin templates define Editor specific plugins. If created and a Standalone build is run, the application will attempt to link in editor libraries in game mode and will run into issues when you hit any key. The fix is to specify an Editor module description for these plugins.

• The scrollbar will now remain at the bottom of the Output Log when a filter is specified.

• Importing a Camera from an FBX will now create a Cinematic Camera with the specified focal length, field of view, and film back settings.

• FBX Reimport now log messages in the message log window.

• The FBX Reimport API now always returns false if there was some error when reimporting an asset.

• FBX import now logs a message when there is too many bone influences on a vertex.

• FBX files with multiple meshes with the same name is now supported.The importer will generate a number at the end of every mesh with a name clash.

• Spline mesh actors in the Level Viewport can no longer be moved by transform gizmos in other viewports.

• Clicking on a row in the Data Table editor before committing changes for the current row will now switch to that row after committing the changes.

• Map properties that contain a struct as the value type are now editable when editing a component's properties in the asset editor.

• The Color Picker will no longer stretch if a very long value is entered into a color component field.

• The FBX Scene Reimport is now marking all reimported asset dirty.

• The FBX importer is no longer using SkinXX workflow to import Static Meshes. It now uses the Material Name Slot workflow.

• Changed how vertex colors are propagated when merging Spline Meshes using the Merge Actor functionality. This used to caused faceted vertex colors.

• Now when painting, you won’t be able to activate any other input other than the painting input.

• Changed Panel Widget’s Remove Child At function to not release slate resources if the child is a User Widget.

• Near Clip Plane now adjusts to the user’s scale to avoid clipping too early at small sizes.

• Updated first include of Plugin Templates as Private PCH files were deleted.

• Disabled “Convert to Static Mesh” option if only unsupported types are selected (e.g. Cable Components).

• Level viewport 'show stats' option is now enabled by default, which avoids confusion with artists thinking lighting is built, when really the message is hidden.

• Object’s IsAsset function now returns false if the outermost package is RF_Transient as well. Also, updating the creation of the Transient Package to be RF_Transient. This makes it so transient packages created by sub-editors for things like previewing a streamed in level instance no longer show up in the Content Browser.

• Made rebuilding lighting faster by importing lightmaps in multiple threads.

• Added extra content to crash analytics and crash reports from the Editor.

• Made an optimization to pasting multiple brushes, so that geometry is not constantly rebuilt for every brush that's added. This improves performance by a couple of orders of magnitude!

• Editor creates a string representing user activity from the details of the currently active tab.

• Editor user activity is sent as part of crash-related analytics and crash reports to give context.

Content Browser

• New: Added a new View Option to the Content Browser for “View Plugin Content”. Originally Engine and Game plugins were only shown when clicking Show Plugin Content, but this made it difficult given the number of Engine Plugins. The new View Plugin Content option makes this easier to locate. In order to see the Engine plugins you'll need both Engine Content and Plugin Content checkboxes enabled.

• New: Added 'play/stop' button to sound wave thumbnail in Content Browser when you hover over the asset.

• New: Added a setting to allow the Sources Panel to be expanded by default.

• BugFix: Fixed text properties exported to asset tags displaying in their NSLOCTEXT form in the asset tooltips.

Foliage

• New: New Foliage Tool Features:

  • A new painting mode was added to add a single foliage instance at a time.

  • Add the possibility to only paint in the current level.

• New: Added the ability for Foliage LOD dithering to be disabled on a case-by-case basis by unchecking the "Dithered LOD Transition" checkbox in the foliage materials. Note that all materials used on all LODs need to have the checkbox checked in order for dithered LOD transitions to work.

• BugFix: Fixed an issue where the Hierarchical Instanced Static Mesh Update Instance Transform Blueprint function was not updating bounds for instances that changed location.

• BugFix: Fixed an issue with static lighting on Foliage and Instanced Static Meshes where the shadows on LOD levels other than LOD 0 was incorrect.

  • All sub-LODs must have the same lightmap UV layout as the base LOD.

  • There is currently a map check warning indicating this. This warning can be ignored if your sub-LOD lightmap UVs are set up appropriately.

• LOD for Foliage and Hierarchical Instanced Static Mesh Components is now consistent with regular Static Meshes and uses a new screen size calculation.

Landscape

• New: Added an eyedropper to select Flatten Height in the Flatten tool.

• BugFix: Fixed a crash when trying to edit Landscape with r.LightPropagationVolume=1 enabled.

• BugFix: Fixed a crash when changing Landscape LOD settings with the LandscapeGrass "Use Landscape Lightmap" option enabled.

• BugFix: Fixed a crash when opening the Persistent level with a streaming level that was hidden in the Levels window, and that streaming level had previously been duplicated outside the editor and contained a Landscape.

• BugFix: Fixed an issue where levels were unable to be saved after Landscape components with tessellation were moved to another level.

• BugFix: Fixed an issue where negative LODBias on Landscape components was not having any effect.

Material Editor

• New : Various Minor improvements:

  • Named each Parameter uniquely either from copy/paste of any creation.

  • Changed the default value for Scalar and Vector Parameter to 1 and (1, 1, 1, 1), respectively.

  • Added a Promote To Parameter when clicking on an Input pin that will generate proper node type based on type pin type.

  • When editing a color property update the Material Expression preview.

Animation Editor

• Removing LODs from Skeletal Meshes can now be undone.

Sequencer

• New: Added current camera to Level Sequence Player Snapshot to allow any property to be displayed in the burn-in. Adjust Default Burn In to include a few more parameters like Focal Length and Focus Distance.

• New: Added toggle to Movie Scene Capture to override Engine Scalability Settings to use Cinematic Scalability option.

• New: Draw where the In and Out  points of the show section are, just like sub-sequences do. Change to only draw the green starting line if Start Offset is negative.

• New: General Options button menu has been refactored into Play Options and Select Options.

• New: Added Select Sections in Selection Range and Select All in Selection Range.

• New: Added hotkey, Ctrl + L, to toggle Camera Cut track to lock/unlock the camera.

• New: Added the ability to copy/paste tracks in Sequencer.

• New: Sequencer now shows the Camera Name in the Cinematic viewport.

• New: Added the option in Sequencer to lock the playback ranger per movie scene.

• New: Added the option in the Curve Editor to show time in frame numbers.

• New: Added Minimum handle size for time slider scrubber.

• New: Added menu options in Sequencer to reduce keys of all sections in the current Level Sequence.

• New: Exposed Curve Editor settings to Editor Preferences.

• New: Added the ability to trigger Events with parameters.

• New: Added hotkey to Sequencer for the ability to restore all states that have been mutated by Sequencer by using Ctrl +R. See “Restore Animated State” button on the toolbar.

• New: Added the ability to override bindings when playing back a Level Sequence on a Level Sequence Actor.

• New: In Sequencer, added the ability to step to beginning.

• BugFix: Fixed a crash caused when attempting to stop a Level Sequence player while it is being evaluated.

• BugFix: Fixed a crash when there are multiple components to attach. Added a component selector when there are multiple components that have sockets to attach to. BugFix: Fixed the offsets that were created when moving multiple sections. The offsets were being created because section bounds were being generated for all sections except for the current section. Instead, they should be computed for all sections except for any that aren't being moved.

• BugFix: Fixed an issue with export from Master Sequence not finding bound objects.

• BugFix: Fixed an issue with Sequence Recorder to not update the current sequence name if it's already set. This fixes a bug where if you pass in a sequence name to record to, it gets reset to the name in the sequence recorder settings.

• BugFix: Fixed an issue with Cinematic Camera to allow manual focus distance when focus smoothing is enabled.

• BugFix: Fixed issues to allow for component keyframing.

• BugFix: When converting Matinee to Level Sequence, fixed matinee 3D scale track conversion to Level Sequence.

• BugFix: Fixed an issue with Cancel when doing a Save As so that it doesn’t continue to save.

• BugFix: Fixed some recorded components not being generated.

• BugFix: Updated Sequencer to properly fire events once per loop.

• BugFix: Teleport simulating components when moving them through the transform track. This fixes bugs with recording simulating actors (ie. vehicle game) where recorded actors don't playback with the recorded positions and there are warnings about attempting to move a fully simulated Skeletal Mesh.

• BugFix: Fixed the play rate track interaction between servers and clients.

• In the Curve Editor, Set Tangent to user when flattening or straightening tangents only when the tangent mode is auto and the interp mode is set to cubic.

• Set Snap Time to Dragged Key on by default.

• Set the paste keys time to the current time, rather than the mouse time.

• Remove click to rename shot functionality in the shot thumbnail. Added rename shot to the Shot Context menu.

• When converting Matinee to Level Sequencer you can set the default scale when converting matinee move tracks to sequencer.

• Audio Start Time in Sequencer is now deprecated in favor of Start Offset which is an offset into the audio clip.

• In Sequencer, the Spawnables are no longer destroyed when the cursor leaves the master playback range.

• In Sequencer, Remove click to rename shot functionality in the Shot Thumbnail. Added a Rename Shot to the Shot Context menu.

Source Control

• BugFix: Fixed source control to properly notify when files need to be checked out if a Blueprint node is dragged.

• BugFix: Fixed an issue with saving a package that doesn't exist on disk but exists in P4 at a newer revision when the user chooses 'Mark Writable'.

• The P4Changelist command line option is now respected by all Perforce operations that support it.

• Subversion binaries should now support SASL authentication.

• Integrated fix to support named changelists in SVN.

• Git plugin: Multiline initial commit message and other connect screen cleanup.

Static Mesh Editor

• New: Static Mesh LODs can not be removed without having a reduction tool (such as Simplygon) configured for use in the editor. Use the “Remove LOD” button under each LOD section or adjust the “Number of LODs” slider and hit Apply.

• New: Added the possibility to copy/paste Material list, Material Item, Section List and Section Item to the Static Mesh Editor and Animation Tools Editors.

• BugFix: Fixed a crash when KDOP collision generation fails and there are existing collision meshes selected. We no longer clear out unrelated collision primitives when KDOP generation fails.

• BugFix: Added a guard against rendering crashes when a mesh with no LOD resources is opened in the editor.

• BugFix: Fixed issues with the Static Mesh sockets on reimport. Socket transforms are now updated correctly and deleted sockets will be removed on reimport.

• BugFix: Undoing a change in the Mesh Preview Scene viewer will now correctly update the changes in the scene viewport.

• LODs other than LOD0 can now have a screen sizes greater than 1.

VR-Editor

• Fixed difficulty with double-clicking with Oculus Touch.

World Browser

• Disabled distance culling when rendering preview images for world composition. Otherwise images were missing culled objects.

World Outliner

• BugFix: Prevented a crash due to duplicate items in the World Outliner if Actors somehow end up attached to themselves.

Gameplay Framework

• New: Force Feedback Effects can now be previewed via the Content Browser.

• New: Significance Manager plugin has been moved out of Experimental.

• New: The Gameplay Abilities system has been moved into a plugin. It can be enabled in the Plugin settings, but it is still experimental.

• New: Added the ability to override Crouch/Uncrouch status in Character Movement Component with Update Character State Before/After Movement.

  • Fixed issue where uncrouching while on top of a physics object would cause penetration and incorrect behavior.

• New: Added Set Auto Activate Blueprint function to Set Auto Activate, which is safe to call from Construction Scripts.

• New: The Gameplay Tags Editor module has been moved to a plugin, while the Gameplay Tags module is now part of the core engine. System internals and performance have been significantly improved.

  • Gameplay Tags can now be added directly from C++ code with AddNativeGameplayTag. Tags added this way do not need to exist in another ini or data table.

  • There is now a Gameplay Tags Project Setting page that allows editing all shared tag settings and managing existing tags.

  • It is now possible to Find Reference, Rename, and Delete tags from the tag management UI. Find Reference will only work on assets that have been resaved in 4.15.

  • Much of the existing C++ API for Gameplay Tags has been deprecated and replaced with a simpler API using Matches/Has or MatchesExact/HasExact. Some broken utility functions were removed.

• New: Added two "virtual buttons", Virtual Accept and Virtual Back that should be used for your menus if you ever need to run on a platform where the Face Button Right is accept, not Face Button Bottom (i.e. Switch). Engine and Epic game code has been updated to use them.

• New: LOD distances have been consolidated between Skeletal, Static and HLOD meshes.

• BugFix: Avoid a crash when calling a Character’s Set Replicate Movement when not on the Server.

• BugFix: Fixed a crash when travelling between levels if an Always Loaded sub-level was hidden.

• BugFix: The correct significance is now chosen when multiple viewpoints are in use.

• BugFix: Tick functions that are disabled in a frame where they were scheduled to execute will now be prevented from executing.

• BugFix: Blueprinted Level Sequence Actors will now correctly receive a tick event in their Blueprints.

• BugFix: When modifying properties of an Actor during Simulate in Editor (SIE), Expose on Spawn properties will no longer be reset to class defaults.

• BugFix: Player Camera is once again positioned correctly at the start of a level even if the game is immediately paused.

• BugFix: Player Controllers are now kept in the same order when going through a seamless travel map transition, which fixes Get Player Controller calls.

• BugFix: Fixed extra white space not being removed in front of console commands.

• BugFix: Actors attached via the World Outliner to a Child Actor will now remain properly attached when making viewport changes.

• BugFix: Fixed Game Mode Base’s Get Game Session Class to return Game Session Class when set.

• BugFix: Fixed an issue where Character Movement Component’s “On Teleport” was improperly changing movement mode.

• BugFix: Fixed an issue so that Volume Bounds no longer vanish after hot reloading custom trigger volume code.

• BugFix: Fixed Project World To Screen Blueprint node to work for letterboxed viewports.

• BugFix: Fixed an issue where Sound initiated via the Play/Spawn2D sound functions now correctly display subtitles.

• BugFix: Setting the Max Draw Distance for a primitive component in a Blueprint Construction Script will now work as expected.

• BugFix: Fixed an issue with Spline Mesh Components that would cause them to distort over long distances.

• BugFix: Fixed the streaming pause rendering feature starting a movie even if a movie was already playing.

• BugFix: Child Actors now properly get Begin Play called when spawned from the Begin Play of the Parent Actor.

• BugFix: Fixed an issue that could result in duplicate Child Actors in uncooked Standalone games.

• BugFix: Fixed Character Movement hanging on to a bad/penetrating floor check result and not continuing to check for a valid floor.

  • This only occurred if bAlwaysCheckFloor was set to false. This could, in rare situations, cause the character to continue to attempt to depenetrate an object far away from it until another floor check occurred. To prevent this, we now force a floor check after the depenetration.

• Bugfix: Keys can no longer be added to read-only curves in curve tables.

• Bugfix: Actor Component, Scene Component, and Primitive Component functions are flagged as “Unsafe During Actor Construction” where appropriate.

• Bugfix: The correct socket is now always used when calculating the new world location for attached components.

• Bugfix: When an actor/component is selected that has a Child Actor, the components of that Child Actor are now properly highlighted with the selection indicator.

• Bugfix: Subclasses of AInfo will no longer display a warning when running commandlets about having a natively added scene component.

• Begin Play will now be called in a consistent order, regardless of whether they were placed in the Persistent Level, a streamed level, or dynamically spawned.

• Components are now properly removed from their Owner when manipulated through edit inline new properties.

• Clicking on components of a Child Actor in a viewport will now select the related actor/component.

• Incremental unregister component time and batch size can now be edited from the Project Settings > Engine > Streaming.

Localization

• New : Line-break iterators will now avoid breaking words in Hangul.

  • The default behavior for wrapping Hangul is to use Western-style wrapping (where words are kept as-is) rather than East Asian-style (where words are broken by syllables).

  • This behavior can be controlled by the using the console variable “Localization.HangulTextWrappingMethod” in cases where the old behavior is needed, but since modern Hangul uses spaces, the per-word wrapping is preferred by native speakers.

• New: Legacy-style translation collapsing is now optionally available at PO export time.

  • This mimics the old behavior of the localization pipeline prior to 4.14 (where identical text within the same namespace would be collapsed into a single entry for translation).

  • This can be enabled by setting "Localized Text Collapse Mode" to "ELocalizedTextCollapseMode::IdenticalNamespaceAndSource" (also available via the Localization Dashboard).

• BugFix: Fixed a crash during IME shutdown.

• BugFix: Fixed a selection bug in TSF based Microsoft IMEs on Windows 8+.

• BugFix: Using FText’s Format with an invalid argument no longer strips any associated argument modifier data from the resultant formatted text.

• BugFix: Fixed an issue where IME composition could provide an invalid range if the text was changed while composing.

• BugFix: Fixed localization gather including texts that were instanced or otherwise unchanged.

• Updated User Defined Enum display names to use real FText instances so they can have stable keys.

  • This avoids the issue where the FText display names were cached from an FString, resulting in them having a different identity each time they were re-cached, which lead to localization and deterministic cooking issues.

• The package localization ID is no longer considered significant for PO export/import.

  • This allows texts with identical identities in different packages to be translated as a single entity.

  • If you were reliant on the 4.14 behavior, you can set "Localized Text Collapse Mode" to ELocalizedTextCollapseMode::IdenticalPackageIdTextIdAndSource (also available via the Localization Dashboard).

Networking

• New: MAX_ARRAY_SIZE and MAX_ARRAY_MEMORY from RepLayout are now user-configurable.

• BugFix: Fixed an assert with “UPackageMapClient::AddNetFieldExportGroup” while viewing replays.

• BugFix: Fixed edge cases/alternate IPv6 formats in IPAddressBSDIPv6’s Set IP.

• BugFix: Fixed OSSNull server/session filtering to better match Session Settings and online OSS. Made MCP, Steam, and Null LAN queries more consistent.

• BugFix: Fixed an issue where movement would be disabled after possession of a pawn.

• BugFix: Fixed a potential DDoS vulnerability.

• BugFix: Fixed an issue that could cause replication conditions for properties to not be re-evaluated before saving those properties to replay checkpoints.

Other

• New: Media Assets: Added support for quadraphonic audio sinks.

• New: Media Assets: Added Blueprint functions to query width, height, and aspect ratio of Media Texture instances.

• New: Media Assets: Exposed “Can Play Source” in Blueprints.

• New: Media Assets: Moved media player implementation into reusable class; also moved overlay text handling into separate asset.

• New: Media Assets: Allow pausing while buffering media.

• New: Wmf Media: Added support for Motion JPG (.mjpg).

• New: Wmf Media: Added support for non-RGB32 uncompressed formats.

• New: Wmf Media: Added rudimentary H.265 HEVC support for Windows 10.

• New: Wmf Media: There is now a progress bar showing while the media is being resolved.

• New: Added for video framebuffers with horizontal and vertical padding.

• New: Added ”On Get On Screen Messages” delegate to Core Delegates. This delegate can return severity-categorized text messages to be displayed on screen.

• BugFix: Wmf Media: Fixed a crash when attempting to play or seek with an uninitialized Media Player.

• BugFix: Wmf Media: Fixed an issue with RGB32-encoded AVIs rendering upside-down and too bright.

• BugFix: Wmf Media: Reworked fallback stride calculations to fix issues with some video formats.

• BugFix: Media Player Editor: Media player selection is ignored if media specifies player overrides.

• BugFix: Media Player Editor: Fixed successful attempts at opening media reporting failure in some cases.

• BugFix: Media Player Editor: Fixed an issue to show desired player name instead of current player name if no media is loaded.

• BugFix: Media Player Editor: Media Player asset is properly marked as dirty when creating a sound wave or texture for it.

• BugFix: Media: Fixed NV21 conversion shader scaling.

• BugFix: Media: Fixed NV12 and NV21 support.

• BugFix: Fixed platform Media Source so that they work correctly in the editor and in other non-cooked use cases.

• Removed most game thread and render thread dependencies from Media Framework (more to follow in 4.16).

• Optimized media handling of RGB input.

• Moved media related enumeration types into separate header file, so they can be shared.

• Continued effort to implement subtitle tracks.

  • Media caption tracks were split into captions, subtitles, and generic text tracks.

  • Caption Sinks were renamed to Overlay Sinks.

• Prevented the user from nesting a platform Media Source in another platform Media Source. There are also runtime guards against this situation in case it’s created through code.

• Prevented loading of media plugins in console apps, such as game servers.

• Added better error message for when no suitable media player plugin was found.

• Media Player Editor: Removed property buttons from Platform Media Source customization.

• Wmf Media: Disabled plugin on Windows 10 because it is currently broken.

Physics

• New: Added Hit Result output to Blueprint “Line Trace Component” function.

• New: Added Debug Draw options (Trace Color, Trace Hit Color, and Draw Time) to shape traces for consistency with line traces.

• New: Window properties are now editable at runtime on Wind Components.

• BugFix: Fixed a crash when reimporting APEX destructibles from apb/x files caused by not allowing the renderer to flush destroy resource commands before emptying an array.

• BugFix: Fixed a crash by removing collision between clothing and external Skeletal Mesh components, as clothing simulations could already be in flight and editing collisions while the simulation is running is not supported by APEX.

• BugFix: Fixed a crash when generating clothing skinning data due to coplanar check triggering a check on small triangles.

• BugFix: Fixed menu extenders in PhAT not being exposed correctly.

• BugFix: Fixed edge cases in Body Instance where stale transforms were used when operations were run in Pre Physics.

• BugFix: Fixed collision issues with Procedural Mesh Components that were created from Begin Play in cooked builds.

• BugFix: Fixed non-uniform scaling of collision on meshes with rotated convex elements.

• BugFix: Various thread-safety fixes to wind data. The components are tracked alongside their scene proxies so the game thread can safely access the wind data.

• BugFix: Fixed welded bodies so that they now properly compute mass properties when attached bodies have a different physical material or mass override.

• BugFix: Fixed an issue where collision shapes could be generated with multiple polygons making up a single flat face causing the body to jitter when resting on that face.

• BugFix: Fixed an issue with line traces not working properly in editor worlds when physics substepping is enabled.

• BugFix: Collision traces that start under a heightfields will now register properly with those heightfields.

• BugFix: Fixed an issue where simulated bodies could have their transforms changed during simulations.

  • This is an invalid operation as it means the physics simulation and the user's input will conflict. The old behavior was that we would pick one in an undefined way. This resulted in subtle timing bugs. To prevent this, we now ignore the transform of simulating bodies in this small window during simulation and will ignore the user's input.

• Replicated movement has been disabled for Actors that are welded to another physics object.

Platforms

Platform-specific release notes for PS4, XBoxOne, and Switch are available in the forums and UDN for approved console developers.

General

• BugFix: Added Desktop Rect and Work Area to Monitor Info for desktop platforms. This is used to fix an issue in Scene Viewport where windowed fullscreen mode would be forced to the primary monitor, and incorrectly positioned on desktops where a taskbar/dock/etc. was on the left.

• BugFix: Fixed support for the Optimize Code setting on Mac, HTML5, Android, Linux, iOS, and Xbox One. This controls optimization level in Debug Game configurations.

• Changed how plugins will upgrade a project to be code-based. Instead of only upgrading some platforms, we now upgrade all to code-based. If only some are upgraded, the .uplugin file won't be staged, so the runtime won't know to disable the plugin that the project was trying to use. You can remove the platform from the whitelisted platforms in your .uproject's plugin list, instead of trying to disable the platform on a per-module basis inside the .uplugin file.

All Mobile

• New: Added "Optional Mobile Features Blueprints" module that exposes sound volume, battery level, determining if headphones are plugged in, and on Android the system temperature.

• New: Added a module that provides a common interface for mobile platforms to access GPS/location data in Blueprints.

• BugFix: Fixed an issue where lighting build would not stick during the first editor session for a newly-created Mobile project set up as Scalable 2D/3D (which disabled the Mobile HDR setting).

• BugFix: Fixed an issue where the  Absolute World Position Material node with the "Excluding Shader Offset" flag set would return zero on ES2 devices.

Android

• New: Added support for MadCatz C.T.R.L.R. controllers.

• New: Added the ability to set element value with new text parameter for UPL .

• New: Added new Project Setting “Use ExternalFilesDir for UE4Game Files”. This will place all files into ExternalFilesDir for automatic cleanup on uninstall for distribution packages, if enabled.

• New: Added a first pass at improved virtual keyboard for Android. This is an experimental feature.

  • Enabled by placing -NewKeyboard on the commandline, or setting IsUsingIntegratedKeyboard to a value greater than zero in AndroidPlatformTextField.cpp.

  • Currently does not deal with Slate editboxes covered by the keyboard; make sure you place your controls in a visible area.

• BugFix: Fixed a crash on 1st generation Kindle tablets if loading Oculus libraries as part of a project.

• BugFix: Fixed a crash that would occur if you changed the orientation of your device during the Splash screen on Android when set to Sensor Orientation.

• BugFix: Fixed an issue to allow Android console command sender to work with ADB version 1.0.36.

• BugFix: Fixed an issue when deploying an Android apk over wifi using Launch On.

• BugFix: Fixed IWYU issues for Location Services plugins.

• BugFix: Fixed x86 and x86_64 libpng" libraries for Android.

• BugFix: Corrected memory stats for Android so that it now works like Linux.

• BugFix: Fixed handling of ETC2 filtering by Google Play Store (If only ETC2, require ES3.0+, but doesn’t use texture filtering manifest).

• BugFix: Fixed #includes in deferred Android OpenGL.

• BugFix: Fixed a driver bug and using separate context for MediaPlayer14, which corrects some render state problems with the movie playback.

• BugFix: Fixed some issues with cooking when sending “On Target Platform Changed Supported Formats” when format changes in Android Project Settings.

• BugFix: Fixed deploy packagename to use Target Name instead of App Name.

• BugFix: Fixed some warnings from TcpMessaging that appeared in the Editor session’s log window when launching on Android.

• BugFix: Fixed issues where most textures appeared black when running in Vulkan mode and packaged with ETC1 textures.

• BugFix: Fixed issues with Mac and Linux install and uninstall scripts if ANDROID_HOME not set.

  • ES 3.0-capable devices which do not have floating point framebuffers and require the Mosaic HDR emulation mode are no longer limited to a resolution of 1024 pixels.

• BugFix: Fixed the handling of numbers in input dialog for number fields, which now allow for sign and decimal.

• Standardized the media track DisplayName in Android media player.

• AndroidManifest now contains ES2.0 instead of 3.0 minimum when Multi and ETC2 and PVRTC selected and enabling all texture formats removes all restrictions.

HTML5

• New: We now support Emscripten 1.36.13 with SSE2 fixes.

• New: We now support Cook-On-The-Fly for HTML5 builds.

• Bugfix: 404 now sends the required double newline after headers.

• 32-bit Mobile HDR shaders have been removed from HTML5 because all major browsers support floating point render targets. This change reduces memory usage and content download size.

iOS

• New: Added the console variable “rhi.Metal.SupportsIntermediateBackBuffer” to control whether to use an extra render-target so we can support screenshots & movie capture, or render directly to the back-buffers to save memory & GPU performance. Still defaults to ON for Mac & OFF for iOS/tvOS.

• New: iOS Audio Improvements:

  • Audio data is streamed from disk instead of memory when the bStreaming flag is set on the source. (The experimental audio streaming flag must be enabled in the Editor Preferences > Experimental).

  • When not streaming from disk audio data is kept compressed in memory and decompressed on the fly as needed.

• New: Support for iPhone 7 and iPhone 7 Plus has been added.

• New: Exposed the bEnableRemoteNotificationsSupport ini setting in the iOS Project Settings.

• BugFix: Fixed a crash on iOS Metal caused by trying to set texture-descriptor fields that aren’t available on older versions of iOS.

• BugFix: Fixed a crash in FMallocBinned Get Allocation Size on iOS 9 that can happen when making use of Apple’s CFNetwork Library.

• BugFix: Fixed a crash in “FMetaldynamicRHI::RHIAsyncReallocationTexture2D” for PVRTC2 textures.

• BugFix: Fixed missing initialization for the Metal Texture Cache in Avf Video Sampler.

• BugFix: Fixed code signing for projects with iCloud enabled.

• BugFix: Fixed “Use Full Precision” Material flag on iOS, which had no effect when using Metal shaders.

• BugFix: Fixed many issues with iOS push notifications (Xcode project fixes, entitlements files, etc).

• BugFix: Fixed an issue where the wrong Launch Image is displayed during startup on iPad.

• Removed 32-bit MobileHDR shaders from iOS, because all supported devices support 64-bit render targets. This change reduces package size and memory usage. These shaders had already been removed from Android, as its shaders are patched on required devices at startup.

Linux

• New: It is now possible to launch your project on a remote Linux machine from the editor or UFE.

• New: Updated bundled libc++ to 3.9.

• New: DSOs can specify the mode (RTLD_GLOBAL/LOCAL) with which the engine will open them.

• New: Added support for touch events (e.g. from a touchscreen).

• New: Server will now crash the hung thread with SIGQUIT.

• New: The engine will default to OpenGL 4.x code path on Linux unless -opengl3 is passed on command line.

• New: All Linux targets will use binned malloc by default (previously some would use jemalloc).

• New: Linux architecture (x86_64, ARM, etc) can now be set per project.

• New: Added CEF support on Linux (x86_64 only).

• New: Added prebuilt websockets library for Linux.

• New: Added verbose printout whenever GL context's vblanc sync is being configured.

• New: Linux remote devices added in editor's device manager will now be saved in Project Settings.

• New: Linux touch events are filtered to prevent multiple OnTouchMoved events with the same location.

• New: Added support for AArch64 (64-bit ARM) architecture.

• New: Added build-essential to dependencies installed by Setup.sh so the engine can be built on Windows 10 Ubuntu subsystem.

• BugFix: Fixed a crash when editing Skeletal Meshes on Linux.

• BugFix: Fixed a crash on exit due to unsafe use of virtual functions in FRunnableThreadLinux.

• BugFix: Fixed long-standing GL crash when using vertex attrib binding.

• BugFix: Fixed a crash when opening Project Settings on Linux.

• BugFix: The engine will not refuse to start as root on platforms other than x86_64 (e.g. ARM).

• BugFix: Projects are now properly associated with the engine version or installation.

• BugFix: Fixed GL4 rendering issues with tessellation.

• BugFix: Fixed remote deploying of a packaged build to Linux.

• BugFix: Fixed launch on a remote Linux machine.

• BugFix: Fixed an issue for determining installed Linux cross-toolchain.

• Bugfix: Use response files for ar (fixes cross-compilation failing due to too long command lines).

• 4.15 will compile with clang 3.9.x with fewer suppressed warnings.

• Disabled XGE when cross-compiling on Windows again (does not work well with clang 3.9).

• Updated code which determines number of cores to produce the correct result on ARM boards.

• Test configuration will drop core by default.

• Removed hard-coded paths to mono binary and replaced it with a script.

• “always_inline” is no longer applied to FORCEINLINE functions in debug builds.

• Speed up bForceCompilationAtStartup=True when nothing changed.

• Remove forced -windowed when launching from the editor.

• Bootstrap script is now independent of the working directory and can be started via symlink.

• Large mouse movement workaround will not be applied if the application has only one window.

• SDL audio subsystem will no longer be initialized (it is not used anyway).

Mac

• New: Experimental Metal EDR/HDR output support for Macs with HDR displays running 10.12 or later.

• New: Disabled OpenGL support on Mac. -opengl command line param is now ignored, we always use Metal. On old Macs that do not support Metal we show a message saying that the app requires Metal and exit.

• New: Added Mac support for the experimental Alembic importer plugin.

• New: Changed "OS X" to "macOS" in few places where we display it and updated the code that asks users to update to latest version to check for 10.12.2, as this version is strongly recommended.

• New: Implemented Info string in Avf Media for display in Media Player Editor.

• BugFix: Fixed a rare crash in CoreAudio on quit.

• BugFix: Fixed a crash caused by an attempt to use Global Play World Actions in Play World Commands before it is initialized when showing suppressible warning dialogs in Editor Engine’s Update Auto Load Project.

• BugFix: Fix a potential crash due to unnecessary reinitialisation of the MetalRenderPipelineDesc mutex.

• BugFix: Fixed an intermittent crash caused by trying to record statistics on an unregistered thread in Mac Metal.

• BugFix: Fixed a crash opening Skeletal Mesh assets on Mac caused by a bug in SSkeletonTreeView.

• BugFix: Setup GPUSkinCache so that it can be enabled on Mac Metal without crashing, though rendering errors persist.

• BugFix: Ensure that only Mac Metal compiles shaders that use Volumetric & Vertex-Shader-Layer rendering features, allowing 3D color look-up textures for the tone mapping to be used on Mac.

• BugFix: Avoid a suspected bug in Nvidia's Metal driver that caused flickering tiles on screen by using the older tiled-reflections algorithm on Metal for now.

• BugFix: Fixed an issue with Metal that meant updates to G8_sRGB textures could corrupt the texture data.

• BugFix: Fixed an error in vertex-declaration handling for Metal that could result in corrupt particle rendering.

• BugFix: Fixed a Metal validation error caused by using a GizmoMaterial in-game which wasn't configuring the compositing parameters correctly.

• BugFix: Fixed incorrect rect initialization in Mac Get Display Metrics.

• BugFix: Fixed an issue with HTTP. If-None-Match response code on Mac and iOS.

• Changed the minimum supported macOS version setting in Info.plists to 10.11.6.

• Changed the Mac-specific high DPI code to use system backing Scale Factor only if “NS High Resolution Capable” in Info.plist is set to true. This solves the problem with macOS Sierra giving us actual backing Scale Factor values even in low DPI modes.

• Decreased the number of max open files for a thread on Apple platforms from 256 to 192 to leave more file descriptors to Cocoa. This will hopefully fix some rare, random crashes in Cocoa.

Windows

• New: Windows XP support has been deprecated to allow the engine to use new Windows features that are not available when supporting Windows XP.

  • The option to set the minimum Windows version to Windows XP in the editor has been removed.

  • Code support for Windows XP will be removed in a future version.

  • A deprecation warning will be emitted from Unreal Build Tool if building with Windows XP.

• BugFix: Fixed an issue that caused devices in the Device Manager window to display the wrong platform.

• BugFix: Fixed an issue with Windows Media Player that would initialize the movie player texture on first frame regardless of whether or not the decoder has a sample ready. This prevents a white texture from showing up for a frame.

• Moved the MfMedia plugin out of an XboxOne directory, because it works in Windows using public APIs (i.e. does not need to be hidden in an NDA'd directory).

• Put the AllDesktop cooking target back in to Windows File | Package menu.

• Disabled the GameExplorer startup checks on Windows Server edition because of rare crashes, and it's not a useful check on Server edition anyway.

Programming

• New: Ensured that QAGameEditor can successfully be built as a monolithic executable.

• New: Added error handling to symbol store uploading.

• New: Added the command line option DisableUploadSymbols to disable symbol uploading.

• Bugfix: Fixed custom pre-build and post-build steps being executed when generating project files.

• Bugfix: Fixed invalid arguments being used to compile for .c files with Visual C++.

• Removed direct dependency on LightPropagationVolumeRuntime plugin from DetailCustomizations module.

• Removed duplicate dll names when preparing command line for link process.

• GitDependencies no longer tries to clean working directory files that are excluded or ignored.

• Compiler warnings for using undefined identifiers inside #if and #elif directives are now enabled.

Rendering

• New: Added support for saving 32-bit EXR images when saving HDR frame captures.

• New: Added "Force 128-bit buffers for rendering pipeline" to the High-res Screenshot tool UI which forces full 128bpp rendering and EXR capture.

  • This can be manually achieved with r.SceneColorFormat and r.PostProcessColorFormat.

• New: Added support for texture streaming on Vulkan.

• New: Vulkan now uses the glslang source from SDK 1.0.33.0.

• New: Added support for global clip plane on Vulkan.

• New: Changed some RHI Clear methods to Draw Clear Quad as some platforms can't support scissor/excluderect.

• New: The View Matrices struct has been made immutable.

  • Direct access to the members has been replaced with getters.

• New: Enable or Disable the Temporal AA jitter during the Custom Depth pass is a project setting now.

• New: Complemented the ENQUEUE_RENDER_COMMAND macro with a debuggable Lambda version: EnqueueUniqueRenderCommand.

• New: First step in making the Engine more Friendly for Pipeline State Objects.

  • We are now passing down 2 structs to collect state. Drawing Policy Render State collects state from the high level renderer down to Set Shared State, and Mesh Drawing Policy Override Settings collects state for Drawing Policy creation.

• New: Improved memory usage and texture load order for texture streaming.

• New: The texture streaming build can now be run through the resave package commandlet.

• New: New way to synchronize with future and pending texture streaming requests.

• New: Added "-FullscreenDisplay=N" commandline where 'N' will be the display index always used for fullscreen applications.

• Bugfix: Fixed a crash when running the "RecompileShaders All" command.

• Bugfix: Fixed a crash when using too many texture coordinate sets in a skeletal mesh material.

• Bugfix: 16-bit images for all formats are no longer incorrectly flagged as sRGB on import. Existing content will be unaffected.

• Bugfix: Fixed comments in Rendering Interface.

• Bugfix: HLOD now respects the FreezeRendering command.

• Bugfix: HLOD now correctly handles visibility across multiple views such as split-screen.

• Bugfix: Fixed GPU skin cache getting disabled unless using recompute tangents. It is now always on.

• Bugfix: Fixed missing velocity vectors due to depth fighting when using Pixel Depth Offset.

• Bugfix: Fixed a case where rainbow-like artifacts would appear in the editor caused by uncleared post-process buffers.

• Bugfix: Fixed incorrect cubemap size displayed in the texture editor.

• Bugfix: Fixed fog opacity on alpha composited material.

• Bugfix: Fixed a corrupt texture bug in the Download Image blueprint node, on some platforms.

  • The new Download Image blueprint node returns a Texture 2D Dynamic, rather than a Texture 2D. It may be necessary to reauthor blueprint/code which uses this node to support the change in return type.

• Exposed API for Material Expression Noise and Material Expression Vector Noise.

• Re-enabled Temporal AA for high-res screenshots as long as the frame delay is active (r.HighResScreenshotDelay).

• Improved error and exit codes when failing to find a good Vulkan driver/version.

• Prevented Drop Detail settings from triggering when using fixed framerate.

• The Film Tonemapper (r.TonemapperFilm=1) and DBuffer Decal (r.DBuffer=1) support have been enabled by default for new projects.

  • These settings can be reverted via project settings and the related cvars.

  • Bloom defaults have also been tweaked to match the new look.

• Scene Capture 2D can specify a global clip plane, which is useful for portals.  This requires the global clip plane project setting to be enabled.

• Removed Mac Graphics Switching plugin. OpenGL is not supported and Metal currently cannot do live GPU selection.

FX

• New: Exposed velocity scaling to vertex/surface particles, matching bone/socket particle behavior.

• Now exporting Particle Module, Particle Module Color Base and Particle Module Color to allow users to inherit from them and create their own modules.

Lighting

• New: Added Inscattering Texture controls to Exponential Height Fog.

• New: Added Fog Cutoff Distance, so artists can prevent fog on skyboxes (requires fog to be setup matching the fog that was rendered into the sky texture so that distant mountains match).

• Bugfix: Fixed crash when using overly big lightmaps.

• Bugfix: Fixed shadowmap channel assignment for stationary lights which are not in a lighting scenario level, when a lighting scenario level is present.

• Bugfix: Fixed indirect lighting color on post process volumes.

• Bugfix: Fixed contact shadow primitives thickness assumption from the depth buffer causing screen space shadow bleeding artifacts.

• Bugfix: Prevented a large shadow depth bias due to low resolution causing near plane clipping.

• Level packages are now marked dirty when manually forcing all reflection captures to update allowing the data to be saved correctly.

• Dynamic Indirect Shadows for static meshes using distance fields.

  • Individual Static Mesh assets can enable Generate Mesh Distance Field to compute a distance field, without the memory cost of enabling for the whole project.

  • New Static Mesh Component properties Cast Dynamic Indirect Shadow and Dynamic Indirect Shadow Min Visibility.

  • New World Settings property Dynamic Indirect Shadows Self Shadowing Intensity which replaces the cvar.

  • Added Shadow Resolution Scale to Light Component.

• Support for Reflection Capture intensity with simple reflections, which are the default with Forward Shading.

• Volume lighting samples are allowed outside of the importance volume if their influence affects the volume. Fixes black indirect lighting on movable components in maps with small importance volumes. Volume lighting samples placed on surfaces use a radius that covers the layer height spacing, which prevents an uncovered region between layers.

• When Inscattering Color Cubemap is specified, directional light inscattering is disabled.

• Lerps between 1x1 mip at Non Directional Inscattering Color Distance to mip 0 at Fully Directional Inscattering Color Distance.

• Improved deferred shadowing with MSAA by upsampling light attenuation intelligently in the base pass.

• Forward renderer now supports shadowing from movable lights and light functions.

  • Only 4 shadow casting movable or stationary lights can overlap at any point in space, otherwise the movable lights will lose their shadows and an on-screen message will be displayed.

  • Light functions only work on shadow casting lights since they need a shadowmap channel to be assigned.

• Shader complexity with Forward Shading more closely matches Deferred.

Materials

• New: Various requested material nodes have been added in this release.

  • Input: Pre-skinned Local Normal.

  • Math: Trigonometry, Fast (approximate) Trigonometry, Saturate, Round, Truncate.

• New: Added Pseudo Volume Texture shader helper function for custom material nodes packing 3D textures or flipbooks into a 2D texture.

• Bugfix: Fixed a rare crash when updating base properties of a material instance in an instance hierarchy.

• Bugfix: Fixed potential crash when changing blend mode on a material instance.

• Bugfix: Fixed incorrect shader complexity output for masked materials when enabling DBuffer decals.

• Bugfix: Fixed low quality textures on grass.

• Bugfix: Fixed POM function so that the world aligned mode works on slanted floors, by building a tangent basis using the vertex normal.

• Bugfix: Fixed Actor Position, Pixel Normal WS material expressions for decals.

• By default the material editor now shows the full instruction count for materials to avoid inconsistencies linked to how a material is updated.

  • In general the numbers shown may be higher but this is not a performance regression, only reporting the actual figures used.

• Added missing material expression tooltips/keywords for new nodes based on 4.15 preview feedback.

Mobile Rendering

• New: Added a project option to specify the maximum number of CSM shadow cascades that can be rendered by a movable light.

• New: iOS devices that use Metal API will now use hardware sRGB texture sampling.

• New: Android projects can now be packaged with Mali Graphics Debugger or Adreno Profiler support. The option can be found in Project Settings -> Android. This allows you to debug rendering issues on device using vendor specific tools.

• New: Added mobile renderer support for single sample shadow from stationary lights.

• Bugfix: Fixed rare bug that resulted in crash on some Android devices in the Set Uniform Buffer Parameter function.

• Bugfix: Fixed bug which could cause 2D translucent elements to render as opaque on android devices which do not support fp16 rendering.

• Bugfix: Fixed a bug which could prevent translucent primitives rendering when mobile HDR is disabled and modulated shadows are in use.

• Bugfix: Fixed missing selection outline in Editor Mobile Preview.

• Bugfix: Fixed an issue preventing GPU particles from being correctly rendered on compatible devices in both LDR and HDR modes.

• Bugfix: Fixed inverted shadow culling when rendering CSM shadow depths and mobile HDR is disabled.

• Bugfix: Fixed issue that could cause blank scene captures on devices that use 32 bit HDR encoding.

• Bugfix: Fixed brightness issues with some UMG elements in Editor mobile preview.

• Generating GLSL shaders for ES2 should be a bit shorter now.

• Disabled dynamic buffer discarding on Adreno330 based devices. This was causing ~10ms stalls on UI rendering.

• Splitscreen multiplayer should now correctly render all views in LDR and HDR modes.

• Do not initialize Minimal Dummy Forward Lighting Resources for unneeded feature levels (below SM4).

• Moved high-end mobile preview mode out from experimental, added iOS Metal, ES3.1 and Vulkan quality level preview options.

Optimizations

• New: Added texture streaming data in material for each used texture.

• New: Optimized the async texture streaming task.

• New: Iterative level processing to prevent stalls in the texture streaming manager.

• New: New required texture resolution viewmode.

• New: AMD cards on GCN architecture can now take advantage of the Depth Bounds Test optimization.

• Precomputed shadowmaps no longer enable Force 2 To 1 Aspect, which is only needed for lightmaps, and saves some shadowmap memory.

• Laptops with discrete AMD GPUs will now select the discrete video cards instead of the integrated.

Postprocessing

• New: Added new options for higher-quality upsampling when using screen percentage reduction. New modes are controlled by changing r.Upsample.Quality.

• New: Better quality Temporal  AA:

  • Fix for correct edge gradients.

  • Image slightly sharper and less aliased.

  • Fixed and enabled antighosting for dynamic objects.

• Bugfix: Fixed output description extent for upscaling post process pass.

• Bugfix: Fixed a case where scene buffer and viewport sizes mismatched on lower screen percentages causing post processing artifacts.

UI

• New: Adding support for Material Parameter Collections to Slate UI objects.

• New: Added category info to VR Editor User Widgets to improve organization.

• Bugfix: Fixed a potential race-condition where a Font object could be GC'd while the loading screen was using the font cache.

• UWidget is now Blueprintable to allow users to create data only blueprints to adjust the CDO values of the basic UWidget types.

Slate

• New: Improved Canvas Panel render performance by improving batching behavior.

  • Added option to place canvas panel children in same layer using explicit ZOrder setting.

  • Previous behavior placing all children in separate layers is still default.

  • Affects Constraint Canvas in Slate.

  • Affects Canvas Panel in UMG.

• Bugfix: Fixed a crash while updating cursor highlight.

• Bugfix: Fixed a bug where Num Characters In Glyph was set incorrectly for TAB characters.

• Bugfix: Fixed pixel jitter in Slate menus.

  • Mostly seen in Mac version of the Editor.

• SWindow now restores focus back to the widget that last had focus when the window was deactivated.

• Made it so explicitly focusing a slate user that does not yet exist, creates the slate user so that the state is properly maintained in preparation for that user's arrival / input.

• The Ignore Incoming Scale option for the scale box should now behave as expected in more cases.

• Get Relative Layout Scale has been modified to also pass down the prepass scale, otherwise it can't extract out the incoming scale ahead of time before text is measured.

• Added very verbose Slate stats behind a compiler flag to avoid the large overhead of these stats. To enable them you will need to set WITH_VERY_VERBOSE_SLATE_STATS to 1. In order to get indepth Slate stats (with a lot of overhead) you run the console commands:

  • stat group enable slateverbose

  • stat group enable slateveryverbose

  • stat dumpave -root=stat_slate -num=120 -ms=0

• Exposed a cached version of the widget geometry that comes in during Tick, this data has also been made available from blueprints through the Widget interface.  Also made an optimization pass on the class to make some space for the geometry object.

UMG

• New: UMG: Expose label browser for UMG.

• New: Combo box widgets now support keyboard focus.

• Bugfix: Fixed the calculation for widget components screen position if the camera aspect is constrained.

• Bugfix: Fixed some HDPI mode problems with widget position calculation when projecting world to viewport / screen, and other absolute space related transforms.

• Bugfix: Fixed a bug in the widget traversing code in sequencer; widgets inside of Named Slots should now be animatable.

• Bugfix: Fixed some issues with HDPI mode in the widget designer.

• Bugfix: Fixed the web browser widget crashing on Android when packaged for Distribution.

• Widget Blueprints that are saved without a root widget will no longer add a Canvas Panel widget when opened in the editor.

• The Widget Hierarchy will now remember which nodes have been collapsed when moving or renaming widgets.

• Widget Blueprints will no longer experience compile issues when moving a widget from one Widget Hierarchy to another.

• Dynamically changing the style for an editable text box or a multiline editable text box from Blueprints will now update it correctly.

• Space and Enter will now fire OnClicked events for focused buttons.

• Deleting widgets from the Widget Blueprint Hierarchy will no longer scroll the hierarchy view back to the top.

• Widget Interaction Components now default to tick while the game is paused. Widget components that do not tick while the game is paused can no longer be interacted with when the game is paused.

• Spin boxes can now be spun correctly when simulating touch events with the mouse.

• When playing an animation, the first frame of the sequence is now immediately evaluated instead of waiting for the next tick.

• Widget Component's Draw At Desired size property now should also work correctly if the widget is in screenspace.

• We no longer also take the platform DPI scale (used for HDPI) into account when applying UMG's UI scale. Since UMG already provides a DPI scaling system, compounding it with the native OSes produces undesirable results, since the DPI scale curve does not take into account some unknown platform scale set by a user.

• Restored the ability of the Widget Component to directly receive hardware input. The Widget Interaction Component is great for just about every interaction use case - the one it is not is when you actually want the 3D widgets to take focus, and to be able to be typed directly into by the user. The kind of situation where you might want to use them as a 3D menu, in a non-VR environment. By default - Widget Components will not behave in this manner, but you can now use the option Receive Hardware Input to enable the ability for Widget Components to function more like a widget in the screenspace of the viewport.

VR

• New: Updated the GoogleVR SDK to version 1.01.

• New: Exposed “Is HMD Connected” to blueprint. This means that HMD hardware is ready to use. UE4 may or may not be using the HMD now.

• Bugfix: Fixed rendering of Canvas tiles in stereo mode to be rendered for both eyes. This fixes the rendering of the background behind various stats shown by the STAT console command.

• Bugfix: Fixed threading issue on Oculus Touch controllers, which could cause jittering in some circumstances.

• Bugfix: Fixed an assertion when using Oculus stereo layers with MSAA, due to binding an unresolved depth surface.

• New: Added analytics event to Vive HMD initialization.

• New: Updating Oculus SDKs

  • Oculus PC SDK 1.10.0

  • Mobile SDK 1.0.3

  • Audio SDK 1.0.2

  • Platform SDK 1.10.0

• Added a missing render target clear when using a VR hidden area mask and a post processing material.

• Added in a new CVar vr.SteamVR.UsePostPresentHandoff, which defaults to 0. When set to 0, we do NOT use the SteamVR Post Present Handoff, which costs some performance GPU time. When 1, we use the call, and get some extra GPU performance. However, this call is NOT safe for scenes that have frame-behind GPU work, like Scene Capture components and Widget Components.

  • For users that were using 4.14.1, and seeing a GPU timing improvement, that behavior is now off by default.  You can re-enable it by setting vr.SteamVR.UsePostPresentHandoff on your project to get it back.  Be aware that SceneCaptureComponents or WidgetComponents may cause async reprojection in SteamVR to fail in that case.

Programming Release Notes

AI

Navigation

• Added a sanity check to UNavigationSystem::AddElementToNavOctree to guard against DirtyElement.NavInterface being null.

Animation

Skeletal Mesh

• New: Stopped SkeletalMeshTypes.h being globally included.

• New: Refactored SkeletalMesh to use same color buffer class as StaticMesh.

• New: Moved SkeletalMesh skin weights into their own vertex stream.

  • If you were accessing skin weights in VertexBufferGPUSkin, you will now need to use SkinWeightVertexBuffer instead.

• New: Moved SkeletalMeshComponent and SkinnedMeshComponent functions out of SkeletalMesh.cpp and into correct cpp files.

• New: Moved SkeletalMeshActor code into its own cpp file.

• Bugfix: Fixed bug with position offset in skeletal mesh vertex buffer when using high precision UVs.

Tools

• New: Removed hard-coded asset-to-animnode mapping, added SupportsAssetClass virtual instead.

Blueprints

• New: Added UK2Node::ConvertDeprecatedNode which can be used to convert deprecated native blueprint nodes into something else. Fixed several related issues with pin migration.

• Bugfix: Fixed weak references stored in blueprint pins so that they are correctly detected when determining which assets reference other assets.

• Included K2Node_BaseAsyncAction.h in K2Node_AsyncAction.h to fix a compile issue.

• No longer enforcing that game project UFUNCTIONS() have a category.

• Removed support for packaging editor-only Blueprint data in cooked assets (specifically removed all "[EditoronlyBP]" ini settings).

• Fixed a crash that would occur when using the Blueprint Profiler with InputKeyEvents.

Core

• New: Added a warning when a thread-specific pak file reader is used on the wrong thread. This is unsafe, and it can lead to difficult-to-reproduce race conditions.

• New: Added a default constructor to TTuple which value-initializes its elements.

• New: Added PUSH_MACRO() and POP_MACRO() macros for preserving and restoring the state of a macro definition.

• New: Added FCString::Strtoi64() for converting a string to a 64-bit signed integer.

• New: Added a THasInserterOperator metafunction for testing if a left-shift operator exists between two types.

• New: Added GET_ENUMERATOR_NAME_CHECKED for returning an enumerator name as a string while statically verifying that the enumerator name is a valid entry in the enum.

• New: Added aliasing constructors to TSharedPtr and TSharedRef, which allow pointers to subobjects, keeping the outer object referenced.

• New: Deprecated some core functions:

  • Deprecated GetUniqueDeviceId. Use GetDeviceId now instead.

  • Deprecated all platform independent usages of GetMacAddress and related functions. It was not reliable the way it was implemented on PC, and generally a bad idea.

  • Deprecated GetMachineId. Use GetLoginId now instead. That's what it really was.

• New: Added debugger visualizer support for delegates.

• New: Added an error report when deserializing a bool which isn't 0 or 1, which means archive corruption.

• New: Added UEnumProperty which supports non-byte enum classes.

  • Enum class properties will now be UEnumProperties instead of UEnums.

• New: You can now hook delegates to be informed when new classes have been added or replaced via hotreload.

• New: TArray now has InsertDefaulted to complement AddDefaulted.

• New: SearchableNameMap has been added to the Linker and Asset Registry, and is used to find Gameplay Tag and Data Table Row references inside assets.

  • If you have your own system of "special names" you can add those names to this map with MarkSearchableName

• New: Added FGCObjectScopeGuard and TStrongObjectPtr as a convenient way to keep a UObject alive without having to add it to the root-set

  • Both use FGCObject internally to reference the object and keep it alive.

  • FGCObjectScopeGuard is designed to be lean and used as a guard for an existing pointer, whereas TStrongObjectPtr is more "full-fat" and designed to be a replacement for a raw-pointer.

  • Of the two, you should prefer FGCObjectScopeGuard where possible. Also note that TStrongObjectPtr isn't supported by UHT/UPROPERTY as you should just use a raw-pointer in that case (it would do the same thing).

• Bugfix: Fixed Algo::IsSorted() to work with C arrays and initializer_lists.

• Bugfix: Fixed MallocStomp to always allocate at least one byte instead of returning null.

• Bugfix: Fixed TSparseArray::Reserve so that new elements get allocated earlier in memory instead of later, giving the more expected iteration order.

• Bugfix: Fixed some bad memory allocation semantics (e.g. mixing FMemory::Malloc and delete).

• Bugfix: Fixed the TIsZeroConstructType specialization for TScriptDelegate.

• Bugfix: Fixed UObject::IsA crash when reinstancing blueprints.

• Bugfix: Fixed typo in FMallocLeakDetection.

• Bugfix: Fixed FArchive::bCustomVersionsAreReset not being copied when the archive is copied.

• Bugfix: Fixed race condition crash when serializing UClasses.

• Bugfix: Fixed it so calling CreateDefaultSubobject with the bTransient=true flag correctly sets the Transient Object Flag on the created object.

• Bugfix: Fixed several cooking issues with editor-only components and sub objects.

• Bugfix: Fixed TSparseArray debugger visualization of types smaller than 8 bytes.

• Bugfix: Fixed parsing of standalone macros like PRAGMA_DISABLE_DEPRECATION_WARNINGS in UnrealHeaderTool.

• Bugfix: Fixed a memory leak in the task graph.

• Bugfix: Fixed a regression causing an assert to fire in the editor related to UGCObjectReferencer.

• Bugfix: Fixed a very old bug with lock free lists, probably not relevant to anything we currently use.

• Bugfix: Fixed return value of Ar.Tell() being assigned to int32 instead of int64.

• Bugfix: Added a thread safety fix for UBlueprintGeneratedClass::PostLoadDefaultObject while UBlueprintGeneratedClass::SerializeDefaultObject runs on the async loading thread.

• Clarified the error message emitted when binding a delegate to a pending kill object.

• Deprecated TAutoPointer.

• Deprecated TScopedPointer.

• Deprecated TAutoPtr.

• Made TFunction::Unset protected. This is an implementation-only function which doesn't properly destroy the binding (can leak memory).

• Deprecated the use of TEnumAsByte with enum classes.

• Improved comments and added useful utility functions to FAssetPtr, TAssetSubclassOf, and TSubclassOf.

• Shortened LexicalConversion namespace to Lex.

  • LexicalConversion is now an alias for namespace Lex, so cannot have overloads added to it.

• Added some extra safety to FEvent by proxying them avoid bugs with stale events.

• Made FindShaderResourceById and FindShaderById return a raw pointer instead of TRefCountPtr to prevent creating temporary TRefCountPtrs. It is no longer necessary to use TRefCountPtrs as shader serialization has changed and shaders are no longer registered on the async loading thread.

• Added multiple thread safety checks to async loading code.

• Thread Heartbeat will no longer report the same hang multiple times.

• Async Loading code will now detach the linker when resetting async package loader to avoid situations when loading the same asset multiple times results in the following load request finding the old linker after the package has been loading but the async package hasn't been deleted yet (async package for the old request in limbo state but linker exists).

• ModuleManager will now use a critical section instead of FMultiReaderSingleWriterGT to make it thread safe.

  • Removed FMultiReaderSingleWriterGT because it was not fully thread safe.

• Async Loading stability improvements:

  • Made sure all package dependencies are loaded before post loading its objects

  • Added more Linker detach safety checks

Editor and Tools

• New: Added extension point for level editor viewport Show menu.

• New: Added support for "Show Only Modified Properties" filter to DetailWidgetRow.

• New: FPropertyRestriction has been restructured to differentiate between hidden and disabled properties.

  • AddValue and IsValueRestricted no longer exist, use either AddHiddenValue and IsValueHidden, or AddDisabledValue and IsValueDisabled as appropriate.

• Bugfix: Fixed several issues with using the SettingsEditor to modify new module-specific ini files.

Gameplay Framework

• New: AActor::GetComponents can now optionally choose to include components in Actors created via its ChildActorComponents.

• New: Systems can now register console autocompletions without modifying an ini by registering a delegate with UConsole::RegisterConsoleAutoCompleteEntries.

• New: UActorComponent subclasses can now override IsReadyForOwnerToAutoDestroy() to indicate to the owning Actor whether they can begin auto destroying if desired.

• Bugfix: Fixed a crash when player is destroyed and the server checks to see if it needs to force a network update.

• Bugfix: Fixed a crash that could occur when loading streaming levels via the PrepareMapChange and CommitMapChange functions.

• AActor::BeginPlay virtual function is now protected and has a dispatching function instead.

• Adding a new volume class via hotreload now allows that volume to be properly added to the world. Volume classes that are modified by hotreload will remain visualized.

• Added IsPaused to GameModeBase now that the pausers array is protected.

• AActor’s GetAttachParentActor, GetAttachParentSocketName, and GetAttachedActors functions are no longer inappropriately marked virtual.

  • Any class overriding GetAttachParentActor, GetAttachParentSocketName, or GetAttachedActors will need to be refactored to accomplish the intended functionality.

• FAttenuationSettings has been renamed FSoundAttenuationSettings.

• Optimized and cleaned up some Actor methods related to location and rotation.

  • Inlined GetActorForwardVector(), GetActorUpVector(), GetActorRightVector(). Wrapped them to simply call the methods on USceneComponent rather than using a different approach to computing these vectors.

  • Inlined blueprint versions: K2_GetActorLocation(), K2_GetActorRotation(), K2_GetRootComponent().

  • Cleaned up template methods that are used to delay compilation of USceneComponent calls to make them private and prefix "Template" to their names so they don't show up in autocomplete for calls to the public methods.

Networking

• Bugfix: Fixed overflow issues in SerializeProperties_DynamicArray_r. Also, fixed a crash from not ensuring properties were serialized successfully.

• Added an experimental feature for game clients that are recording network replays to do the per-frame recording work on a task thread in parallel with the Slate tick. If Slate is a significant portion of frame time, and client replays are being recorded, this can save a lot of game thread time each frame.

  • Use the console variables tick.DoAsyncEndOfFrameTasks and demo.ClientRecordAsyncEndOfFrame to enable this feature.

Other

• New: CrashReportProcess crash report backend update:

  • InvalidCrashReports now saved to S3 instead of local folder.

  • Removed option to sync MinidumpDiagnostics from Perforce.

  • Moved MinidumpDiagnostics from old Perforce synched location to its own folder.

  • Added improved logging to Slack with option to monitor MDD performance.

  • Added hourly log folder bins to MDD logs to avoid bloated folders and associated performance issues.

  • Added support for types of crashes we don't want to symbolicate (using it to skip callstack gen for hang detected ensures).

• CRP now has improved handling of lost comms with website/DB.

  • Crash reports will not be lost.

• Added compression support for crash files output from CRP to S3.

• Improved MinidumpDiagnostics performance for use on the CR server by CrashReportProcess.

Physics

• Bugfix: Fixed FVehicleAnimInstanceProxy::PreUpdate not calling FAnimInstanceProxy::PreUpdate.

• Added sanitization code around PhysX flags and refactored the ways flags are managed through a single code path.

Platforms

• New: Both RTTI and Exceptions can be enabled. The “Use RTTI” and “Enable Exceptions” flags, respectively, must be set to true in the Module.Build.cs file and in the build configuration file as well.

• Made a generalized "growable heap" allocator that had previously been copied and pasted between RHIs. This is a heap allocator that allocates in large chunks, and then suballocates from within (often with large alignment). Mainly meant for GPU resource memory allocations, but can be used in other circumstances. To use it, you simply implement four easy functions (for creating the memory and other reasons). Allows for more than just a raw pointer to be the result of an allocation.

HTML5

• New: Added HTML5 thirdparty libraries build scripts in python.

• New: Updated HTML5 thirdparty libraries (bash) build scripts to make use of new toolchain version.

• Bugfix: Fixed PhysX for HTML5 crash. Removed 32-bit sized unions when browser floats are 64-bits.

iOS

• New: Added an iOS-specific implementation of the LocationServices plugin.

Linux

• New: Added helper build scripts.

  • Pull source and compile: zlib, openssl, libcurl, and libwebsockets.

  • Dockerfile to setup "CentOS 7" environment (GLibC 2.17 and GCC 4.8.5)

Mac

• New: Extended the internal Metal debugging options for MetalRHI:

  • Added rhi.Metal.BufferScribble, which will fill freed buffer regions with 0xCD to help identify any areas where we are writing to a buffer while it is still being processed on the GPU.

  • Added rhi.Metal.BufferZeroFill, which will zero-fill newly allocated buffer regions before any other data is read/written. Useful for catching cases where we might be reading uninitialised memory.

  • Added rhi.Metal.ResourcePurgeOnDelete, which will purge the backing store of resources prior to releasing them back to the system or the appropriate pool.

  • Added rhi.Metal.ResourceDeferDeleteNumFrames to defer releasing resources to the system or the resource pool by the specified number of frames (in addition to the current policy of waiting for the current end of frame & command-buffer completion). Useful for tracking down resource lifetime errors.

  • Fixed the flickering geometry when enabling rhi.Metal.RuntimeDebugLevel=4 which breaks render passes into separate command-buffers - the occlusion query was waiting on the wrong command buffer in this case.

• New: Extended the Metal state recording when rhi.Metal.RuntimeDebugLevel is set to 3 or greater to include the objects and states used.

  • The object labels, types, and descriptions will be printed on failure. If the object is deleted prior to this, we have a lifetime error and it will crash at this point and can be debugged further using our -metalretainrefs command-line option or Xcode's zombie-objects.

• Extended FShaderResource's OptionalData field to allow arbitrary amounts of data so that Metal shader debug information can be stored in it.

• Redundant state changes in MetalRHI are optimized out.

• Changed FAppleHttpResponse::GetContentLength to return expected content size instead of payload size, so it is consistent with other implementations.

• Do not try to use installed Mono 4.6 on Mac as it is known to have issues on macOS 10.12 (for example building the editor with UBT often fails with Mono running out of file descriptors).

• Added -Wno-undefined-var-template on Mac to work around an issue with compiling UHT in Xcode 8.3.

Programming

• New: Added list of Dependant modules to EULA check so that it's clear what can't be included.

• Removed non-cyclic actions from messages about cyclic actions being present.

• Removed CopyVisualizers.bat now that UE4.natvis is included in the VS2015 solution and we're no longer supporting VS2013.

• Moved Sample game projects into a different solution folder, similar to Templates.

Rendering

• New: Added r.Vulkan.SubmitOnDispatch to help debug compute shader hangs on Vulkan.

• New: Added GDynamicRHI::GetName() to get the name of the current RHI.

• New: Locked buffers are now aligned to 16 bytes to allow SIMD operations on Vulkan.

• New: Reworked Vulkan render pass system.

• Bugfix: Fixed a bug with default parameters on shaders for non-HLSL platforms.

• Bugfix: Fixed a memory leak when using VisualizeTexture on some RHIs.

• Bugfix: Fixed a typo in check relating to stalling the RHI thread.

• Bugfix: Fixed a rare crash with particle systems destroying render state.

Lighting

• Bugfix: Fixed a rare bug with shadow groups rendering things that have not been setup to render this frame.

Optimizations

• New: Glsl source for Vulkan shaders is now stripped out to save memory. Use r.Vulkan.StripGlsl=0 to not remove it at runtime.

• Projected shadows are no longer created when r.ShadowQuality is 0

  • Fixes crash in the forward path trying to render shadows

  • In the deferred path, the shadowmap was still being rendered and only the projection skipped, now all cost will be skipped

VR

• The relative transform of the UCameraComponent will no longer reset if the HMDDevice returns a new position. This avoids changing the entire hierarchy twice during every update.

Mass debug rendering

• Switched fudged auto-LOD calculations to use a power decay instead of a reciprocal.

Upgrade Notes

Animation

Pose snapshot tool

• CVar forcing multithreaded update is now defaulted to off. Projects now enable it by default, but can easily opt-out.

• The setting to enable and disable multithreaded update has moved from the class defaults to the class settings. Any of these flags that were previously set in the class defaults will need to be re-set in the class settings.

• This will change the behavior of morphtarget if SetMorphTarget and animation curves were being used together.

Skeletal Mesh

• If you were using types defined in SkeletalMeshTypes.h, you may now need to include this file explicitly.

Blueprints

• If your project is missing "[EditoronlyBP]" ini settings, or if you've set any of those to false, then you need to upgrade code where you use Blueprint editor-only data in your packaged project.

  • Places where you use UBlueprint objects at runtime will need to be updated. Most commonly, ConstructorHelpers::FObjectFinder will need to be updated to ConstructorHelpers::FClassFinder.

Core

• Deprecated some core functions:

  • GetUniqueDeviceId is deprecated; replace with GetDeviceId.

  • GetMachineId is deprecated; replace with GetLoginId.

  • All platform-independent usages of GetMacAddress and related functions have been deprecated. These functions were not considered reliable on all platforms.

• Any types which inherit TAutoPointer should replace it by implementing their own conversion operators. TAutoWeakObjectPtr implicit conversions should be replaced with explicit Get calls.

• TScopedPointer and TAutoPtr usage should be replaced with TUniquePtr.

• TFunction::Unset usage should be replaced with an assignment to nullptr.

• Any code which finds an enum class property as a UByteProperty should be changed to look for a UEnumProperty instead. Any code which depends on UByteProperty::Enum or UByteProperty::GetIntPropertyEnum should support UEnumProperty as well.

• Usage of TEnumAsByte with an enum class type should be changed to just use the enum class type directly.

• Use of the LexicalConversion namespace should be changed to Lex.

Gameplay Framework

• GameplayAbilities are no longer enabled with the “GameplayAbilitiesEditorEnabled” ini setting. There is now a GameplayAbilities plugin that can be activated for this purpose.

• Activate and SetActive are no longer valid to call on components from construction scripts. Call SetAutoActivate instead.

• For LOD distance consolidation, LOD distances should be converted automatically on load. If you are using update rate optimizations with custom thresholds for skeletal meshes you will need to update these manually.

• The Blueprint API for GameplayTags has changed, but existing nodes should update themselves correctly. There is now an ExactMatch parameter to replace the older enums, so you may need to update that bool in some cases.

  • If you have existing GameplayTag data in Data Tables or .ini files, you will have to migrate them.

  • Searching for GameplayTag usage will only work properly once assets have been resaved in version 4.15 or later.

• Uses of FAttenuationSettings need to be changed to FSoundAttenuationSettings.

• Delete DDC or otherwise change Spline Mesh Component parameters to ensure they get regenerated.

Physics

• Many deprecated collision functions have now been removed from KismetSystemLibrary, and the _NEW postfix has been removed.

• Cooked PhysX convex element data is now in “body space” instead of “element space”. If you are directly accessing PhysX convex mesh data, you may need to take that into account.

• Any simulated body with attached kinematic bodies that have different physical materials, or mass overrides, will now have a correct mass distribution.

  • The old behavior was to use the physical material of the simulated body. This may lead to re-tuning some content. The most likely case is any vehicle with attached kinematics that had special mass properties or mass overrides. As a result of this change, collision boxes with zero mass attached to vehicles will behave correctly.

Platforms

Windows

• It is currently possible to set the minimum Windows version to Windows XP directly in the INI files.

Rendering

• There is now an error when using too many texture coordinates on a skeletal material that displays the following output: "Too many texture coordinate sets defined on GPUSkin vertex input". Previously this case would silently fail and crash when the material was used, now it's correctly blocked. The fix for this error is to uncheck "Used with Skeletal Meshes" on the affected material as this is unsupported.

• Some of the variables have been moved from the SceneView and renamed to be more explicit. Getters that do a lot of computation have been renamed to Compute*

• Prefer EnqueueUniqueRenderCommand over the macro as we want to switch to those on the future

• Remember to take a copy of FDrawingPolicyRenderState before you hand it off to another thread.

Slate

• Improved Canvas Panel render performance by improving batching behavior.

  • Default behavior has not changed.

  • To take advantage of better render performance enable project setting "Engine->Slate Settings->Constraint Canvas->Explicit Canvas Child ZOrder".

  • Recommended for projects using Canvas Panel on mobile platforms.

  • Projects enabling "Explicit Canvas Child ZOrder" must set ZOrder on all Canvas Panel (SConstraintCanvas) child slots to avoid undesirable clipping.

  • Projects enabling "Explicit Canvas Child ZOrder" can place children that will never overlap in the same layer by setting the same ZOrder value to improve batching.

Google Daydream

• Daydream apps require android-24.  This is not installed by default, but can be manually installed with NVPACK\Chooser.exe.