Foundry’s path to the viewer of the future

What You See Is What You Get, or WYSIWYG, is a phrase that gets used a lot when talking about interactive workflows in software tools. It was first used for word processing and page layout software, and then later on for web design. It’s been a long time coming in the realm of 3D software, especially given the particular combination of the industry quality demands, intersecting hardware and software constraints.

Now that many 3D DCCs have reached a level of WYSIWYG between viewport and render, the next question forms around the viability of a WYSIWYG workflow between multiple DCCs, their viewports and the ground truth of a renderer.

Mari has crossed the boundaries of GL and ray tracing, by working with key players in the rendering space to generate approved GL proxy shaders from the people that wrote the path traced versions. With the release of Mari 4.6, there will be accurate GL reproductions of key surface shaders for 3Delight, Arnold, Unreal, V-Ray and RenderMan, which is being distributed by Pixar in RenderMan, not in Mari itself. 

Here, we can see how close the results are between the Mari viewport and an Arnold render inside Katana. There will always be a difference, and that comes down to the nature of GL versus path tracing. However, it is close enough that an artist can make constructive choices, and know when it’s time to continue their work in the final DCC. This offers a close approximation of the final render between Mari and a rendering plugin loaded inside of Katana.

It is fitting, as the Mari viewport was the start of an exciting evolution that plays into the ongoing development of Katana. From the Mari viewport, we created an internal viewer technology, that looped it’s way back into Mari 4 and became the basis of the Modo Advanced Viewport.

The original goal of Modo AVP was to create a GL viewport that matched the Modo offline renderer as closely as possible. You can see from the image above the outstanding work achieved by the team.

Fast forward a year or so, and Universal Scene Description comes into the picture with an exciting technology called Hydra. This framework was designed by PIXAR to meet their complex production needs and was a perfect fit for Katana 3.0, which shipped in May 2018.  Foundry ported USD/Hydra to Windows to support the USD community and embrace Hydra, and with Katana 3.2, we upgraded to USD 19.05. The Hydra tech has been the basis of a much improved viewer experience in Katana for 16 commercial releases, and counting.

It was a giant leap forward, and proved to be wonderful for the Katana artist, allowing them to interact with a lot more scene information than ever before at higher FPS. However, what it provided in horsepower, it lacked in PBR fidelity.

So, our Skunkworks team quietly laboured away blending these two great technologies into something awe-inspiring. Then, at Siggraph 2019 we showed the first early tests of our Advanced Viewport technology, running as a Hydra render delegate inside of Katana, displaying USD assets with their USDShade Preview Surface descriptions.

Though it will still take some time to appear in the commercially released Katana, the implications are clear and offer an exciting look toward the future. Modo, Mari and Katana will share viewport tech that will deliver across a DCC WYSIWYG workflow—Katana being the last piece. 

An asset painted in Mari will look the same in the Modo or Katana viewports. Plus, decisions made in Mari will have close to final results with the Modo renderer, and 4 of 5 commercially supported renderer plugins for Katana.

There is one more layer of icing on the cake. We always want an artist in Katana to be able to interact with what is most often ground truth: the path traced render. So, a forthcoming Katana update will bring with it an exciting technology. We are currently testing a way for all rendering plugins in Katana to draw directly into the viewport, separate from any future improvements in path tracing from the USD Hydra technology.

Better GL fidelity, cross DCC WYSIWYG workflows and finally, working with the ray traced results which use the same tools that make your final frames. A lot of time and work has gone into this, by a great number of people here at Foundry, and all with the goal of empowering our users to make awesome imagery.