RenderMan Version 22.5 is now released. It is a significant dot release, delivering new features and performance gains. Version 22.5 builds upon the major architectural enhancement in RenderMan 22 which was released in July 2018.
Dylan Sisson once again presented at FMX in Germany last week, where he previewed both what is new in RenderMan 22.5 and showed examples using material from the upcoming Toy Story 4 film. He also gave an update to the continuing R&D into Pixar’s next generation of technology: XPU.
Dylan Sisson is a technical artist with over 20 years of experience, he joined the RenderMan Products Group at Pixar Animation Studios in 1999. Sisson is both a part of the development team and leads the charge of RenderMan evangelization.
In his FMX talk, Sisson discussed the new RenderMan for Houdini and the new improvements in RenderMan which turned 30 last year. The new version 22.5 features include
- Adaptive Sampling Fixes (up to 10% to 15% faster)
- Interactive displacement
- Interactive volume density
- RenderMan for Houdini
- Intel Partnership to Accelerate OSL
One of the key speed improvement in RenderMan 22.5 is ‘time to first pixel’. Below are two timed renders of a complex scene. The top clip is in RenderMan version 21 and the bottom clips is in version 22.5
As one can see above, the first pixels appear at around 21 seconds into the test render for the older RenderMan v21 and at the 5 second mark for the RenderMan 22.5 version. These are just test clips but they are indicative of the improvements Pixar has been seeing,
Toy Story 4
Toy Story 4 is the first Toy Story film rendered with the new RIS RenderMan, and while the characters look almost the same, the material properties and environments are definitely significantly more refined that the previous Toy Story 3 characters and their surfaces. A huge part of this is the RIS adaptive path tracing, with such mixed integrated approaches as Manifold walk (Manifold Next Event Estimation) on the character’s eyes, with both uni and bi-direction path tracing in RIS on the rest of the shot.
In the clip from Toy Story 4 above, the fairground has 44,000 lights (and counting as the shot is not final). RenderMan handles many more lights than this, as the film Coco showed, but Toy Story 4 uses Smart blubs for consistent shading. All the bulbs in the scene above are carefully calibrated with relative values. The scene uses Meshlights and global scene wide exposure bulbs, carefully calibrated with relative values.
- If the Sunlight light is 100
- Day light shadows would be 10
- Over cast shadows 1
- Night moon light 0.001
This means that the same scene has the correct light illumination if this scene turns from night to day.
The film’s trailer is below.
As the film’s trailer shows, the action moves to an Antique shop. Sisson showed exclusive clips from Toy Story 4 in his FMX talk. The Antique shop set was built with USD, and contained some 11,000 unique objects from the Pixar Asset library.
USD is proving invaluable not only at Pixar. USD is being used at studios such as Animal Logic, Luma, Mill film and MPC. USD could almost be considered a super set of Alembic and is being adopted by a wide range of equipment and software vendors. “USD isn’t technically a superset of Alembic but it has a superset of the features of Alembic, although, of course, it isn’t built on top of Alembic” commented Sisson.
Pixar itself is “doubling down on RenderMan and USD” says Sisson. He points to the trend of digital live action sets and how entire pipelines are becoming more concurrent. Pixar themselves and others are embracing this new mode and working on interactive complexity. For Pixar, USD is now the backbone of the Asset collaboration. Pixar is aiming to provide direct rending of USD in RenderMan by end of year. It is expected that a more detailed timeline will be visible to users at SIGGRAPH 2019.
Fans of Pixar films will find countless easter eggs from earlier films as the Antique shop houses objects from other films such as antique signs from the 2007 film Ratatouille.
In the new film, the characters race through the back passages of the shelves and junk in the store, which are all coated in dirt, fluff and dusts. Sisson pointed out that this backroom dirt or ‘furniture furies’ actually contain “more hair than the Monsters Inc , ‘Sulley’ character model”.
The Pixar artists created very detailed sets in Toy Story 4. Because the main characters are toys, fine details are important as they showcase the small size of the toys and their unique world perspective. In these images above, set in Second Chance Antiques store, artists and technicians added a layer of dust to sell the setting. They were able to dial up or dial down the dust to best serve the needs of a given scene.
The dust and dirt created for Toy Story 4 used dynamics from Houdini simulations. As part of the general RenderMan 22.5 release, Pixar has released a new RenderMan for Houdini plugin.
RenderMan For Houdini
Pixar’s brand new RenderMan for Houdini (RfH) plugin has been completely rewritten to support the latest interactive workflows in RenderMan 22. RenderMan’s greatly improved integration with Houdini includes interactive modeling, shading, and lighting. The plugin’s features include seamless support for Houdini’s geometric attributes, and the addition of Pixar’s powerful Preset Browser.
Chris Rydalch, Production Technology Technical Director at Blue Sky Studios commented, “the new plugin is excellent. The integration is tight, it makes it easier than ever for our Houdini artists to work in Renderman! We’re all very excited to see the Houdini/Renderman workflow get better and better!”
The new RenderMan for Houdini plugin includes
- Full support for geometry: curves, points, volumes, meshes, and packed primitives.
- Interactive placement and deformation of geometry
- Interactive editing of lights and cameras
- Interactive manipulation of light filters
- Support for Object and Light selection in both interactive and batch rendering
- Texture Manager – Automatic texture conversion to Pixar’s texture format for images referenced in shading nodes
- Preset Browser – RenderMan’s Preset Browser can be used to import and export shaders, light rigs, and HDRI maps
- Ability to denoise with the NVIDIA Optix denoiser when displaying to our Image Tool: “it”
- Ability to cache simulations to RIB archives and use those during interactive and batch rendering
- Support for Material Builder shader networks using RenderMan’s shading nodes
- Interactive support for modifying shader networks and their parameters
- Support interactive adjustment of displacement
- Support for velocity motion blur
- Support for Alembic packed primitives with transform and material overrides
- Support for instancing and point instancing
- Interactive capability to scrub the timeline to examine animation and simulation
- Render region support to have RenderMan render in Houdini’s sceneview
- Support for rendering to Houdini’s native mplay framebuffer and renderview
- All of the standard AOV, LPE, Cryptomatte, Display filters, and denoising capabilities.
- Support for importance sampled emissive volumes
RenderMan for Houdini, allows the creation of amazing visuals using the power of Houdini and rendered interactively with the beauty clarity of RenderMan.The RfH plugin is available for download from Pixar, and it supports Mac, Linux, and Windows OS. It is compatible with Houdini 17.5.173. 17.0.506, and 16.5.634. Sisson explained that Houdini Indie support will be available with an upcoming future 17.5.229 release of Houdini.
Matt Estela, VFX Lead in Residence, UTS Animal Logic Academy commented that, “the new RfH speed is incredible for lookdev. We can adjust fur grooms and see the results in RenderMan almost faster than it updates in the viewport. Some of our students are just leaving the live renderer open all day, that’s how fast and transparent it is.”
RenderMan XPU is not shipping, but Sisson at FMX provided an update on the new hybrid renderer. XPU is the next-generation production RenderMan renderer under development at Pixar. It is based on a unique architecture which allows rendering to use either the CPU or GPU, or to combine both on the same frame to render even faster.
RenderMan XPU leverages the work on interactivity in RenderMan 22 and is further re-architected to take full advantage of the hybrid CPU+GPU platform model. The engineering team is currently focused on speed, quality, and critically: developing a GPU-accelerated system that can handle the immense scale of Pixar production scenes.
RenderMan XPU gives users the flexibility to run the renderer on a workstation, or on an existing CPU-only farm, or a new cluster with GPUs, or on the cloud where pricing may favour different CPUs or GPUs on a given day. The promise of XPU is to deliver the power of GPUs in a seamless, integrated experience without breaking established processes and pipelines.
The RenderMan XPU project is initially targeting highly interactive portions of Pixar’s production pipeline. The full scope of features required for complete production rendering are being added as they become available. Eventually RenderMan XPU will reach the point where it can simply become a future RenderMan release for general customer use. Until then, the existing RenderMan will also continue evolving, and building on the new interactive CPU technology introduced in RenderMan 22. Since the RenderMan XPU technology will be valuable for many interesting use cases, (even in its early stages of development), Pixar is evaluating how and when it might be made available to RenderMan customers. No specific release date has been given, Sisson indicated that delivery of XPU is planned to “rollout in staged R&D releases with limited feature sets. The first R&D release of XPU may happen later this year or early 2020, but a feature complete XPU is still too early to specify”.
Images: ©2019 Disney/Pixar. All Rights Reserved. Toy Story 4 is directed by Josh Cooley, Toy Story 4 opens in U.S. theaters on June 21, 2019.