Building a better car with Adobe Substance 3D and Unreal Engine

As part of its initial launch of the X-TAON and Substance 3D’s automotive collection, a contest was held. Professionals and amateurs alike entered their original designs of the X-TAON, with results ranging from the bizarre to the next hot aftermarket look. One of the winners, environmental artist Ronan Mahon, impressed the judges so much that when it came time to re-introduce the X-TAON, the team at Substance 3D brought him onboard. And he brought Unreal Engine with him.

Second lap

During his time at game studios like Free Radical Design, Rebellion Developments, and Rocksteady Studios, Mahon was no stranger to Substance 3D tools for texturing. Substance did, after all, begin as a game dev tool before expanding into countless industries. But part of what made him ideal to help create the new look of the X-TAON was his experience with Unreal Engine—including years spent working with a modified version of Unreal Engine 3 on the iconic Batman: Arkham series, and more recently with Unreal Engine 4 on upcoming AAA blockbusters like Suicide Squad: Kill the Justice League.

Mahon even created his own app for Unreal Engine that enables users to create decals and certain materials directly in the Unreal Editor viewport. His “Decal Designer” is available now, and was recently tapped by Epic staff for an Unreal Marketplace Showcase.

“Unreal Engine and Substance 3D are such an empowering combination, and when you throw real-time raytracing to the mix, it honestly feels like magic,” said Mahon.

The exterior look of the new X-TAON was a collaborative effort between Mahon and two Adobe Substance 3D employees: Anaïs Lamellière, color material and finish designer, and Nicolas Paulhac, the head of 3D content and one of the originators of the X-TAON project. Together the trio determined the look and textures of the car’s exterior, from the metallic sheen highlighted to the coarseness of the rubber in the tires. Mahon then created much of the interior on his own, giving the new X-TAON a fresh look for 2022.

Bringing motion to a static design

With the general look of the X-TAON established, Mahon began creating a background environment, utilizing the Substance in Unreal plugin and materials from the Substance 3D Assets library (created with Substance 3D Designer). This enabled him to edit and tweak the procedural parameters of a Substance material graph directly in Unreal Editor.

While the X-TAON was the focal point of the video, the background needed to match the level of quality, or it could potentially draw attention from the car itself. Mahon gave careful attention to everything, from the number of blocks in the pillars to the wear and tear of the concrete to the proper color under the selected lights. He then began to focus on the movement of the virtual camera, making adjustments to the look and resolution directly within Unreal Engine.

Reflections were also vital to help convey the sense of movement, so Mahon used RT reflection, GI and AO to make the forms shine. For a show car designed to impress through its looks, reflections on the stylized curves were vitally important. That encouraged Mahon to utilize ray tracing—specifically ray-traced reflections—shadows, global illumination and transparencies, powered by a NVIDIA RTX 3090 GPU.

“I’m a one-person studio, so I can’t waste time waiting for offline renders from large render farms to finish, or even worse, wondering what my final render will look like because my viewport doesn’t match the final output,” said Mahon. “I need to spend my time creating, not waiting.”

That need for a quick change became vital in the creation of the X-TAON video. Late in the production cycle with the video nearing completion, the team decided that the theme for the X-TAON wasn’t quite right. It was a potentially massive shift for a video that was nearly complete, but thankfully, the pipeline was built for exactly this sort of change. Lamellière would adjust the materials to match the new theme, then send them directly to Mahon, who then added them directly into Substance 3D Painter.

Mahon was then able to return to the authoring stage and the texturing, and see the results mirrored with Unreal Engine in real time through the use of the “Auto Reimporter.” That enabled him to continue working on the overall look of the video without worrying about multiple re-renders while the design of the car was in flux. Using the real-time capabilities inherent in Unreal Engine meant the difference between a quick change and weeks of waiting.

“As most creatives will tell you, projects like this rarely follow a linear A to B to C path,” said Mahon. “You really need the flexibility to jump back to the start of your pipeline and make updates and improvements as you go, and this Substance 3D-to-Unreal Engine pipeline enables a lot of flexibility and feedback.”