Implemented some basic 'primvar analysis' in Gatling. The idea is to detect patterns in secondary primvars (not part of vertex layout) and modify data & interpolation. For now, just checking for constant values, which is surprisingly effective for some assets.

New blog post: pablode.com/posts/hydra-...

Primer on writing a Hydra render delegate

A practical introduction to OpenUSD Hydra and the basics of writing a custom render delegate.

pablode.com

Currently implementing Gaussian splatting in guc (glTF to USD converter) so that it can be released as soon as the extension comes out of RC status.

This weekend I added support for the MaterialX <time> and <frame> nodes to Gatling. Procedural materials can now be animated over time, such as this clock authored by Roberto Ziche:

Finally finished Gatling's Metal backend! Here's a teaser of NVIDIA's USD / MDL sample scene 'Attic' running on macOS. What's special about the backend is probably that it uses the same GLSL code as the Vulkan backend, complete with hardware ray tracing. How does that work?

My "No Graphics API" blog post is live! Please repost :) www.sebastianaaltonen.com/blog/no-grap... I spend 1.5 years doing this. Full rewrite last summer and another partial rewrite last month. As Hemingway said: "First draft of everything is always shit".

No Graphics API — Sebastian Aaltonen

Graphics APIs and shader languages have significantly increased in complexity over the past decade. It’s time to start discussing how to strip down the abstractions to simplify development, improve pe...

sebastianaaltonen.com

Blog post on motion blur rendering (which is impressively thorough) by Alex Gauggel gaukler.github.io/2025/12/09/n...

Spent some time this weekend updating Gatling’s Blender integration to the latest 5.0 release.

Ray marching is a common approach to GPU-accelerated volume rendering, but gives biased transmittance estimates. My new #SIGGRAPHAsia paper (+code) proposes an amazingly simple formula to eliminate this bias almost completely without using more samples. momentsingraphics.de/SiggraphAsia...

Btw, a few weeks ago I released a small plugin for usdview. It allows inspection of UsdShade networks using a custom Qt node graph. It’s open source, lightweight and simple to install.

The Pixar RenderMan team has a paper out at HPG 2025 this week about the architecture of RenderMan XPU. There's a lot of interesting details in the paper- definitely a worthwhile read! diglib.eg.org/bitstreams/d...

Small weekend experiment: ported an LCD shader from Blender to #MaterialX (originally authored by PixlFX)

We just posted a recording of the presentation I gave at DigiPro last year on Hyperion's many-lights sampling system. It's on the long side (30 min) but hopefully interesting if you like light transport! Check it out on Disney Animation's website: www.disneyanimation.com/publications...

Walt Disney Animation Studios - Publications

We engage with the global research community through collaborations with universities around the world, publications in academic journals and participation in top-tier conferences.

disneyanimation.com

Implemented USD point instancer primvar support in my toy renderer the last few days. Can now render this 2D Gaussian Splatting (2DGS) scene with a single mesh & MaterialX material. (Created by Oliver Markowski with Houdini, link see below ⬇️)

Thanks to a lot of colleagues' great work, happy to share Vulkan samples for RTX Mega Geometry. They should run on all RTX GPUs using today's new drivers github.com/nvpro-sample... github.com/nvpro-sample... github.com/nvpro-sample... github.com/nvpro-sample...

GitHub - nvpro-samples/vk_animated_clusters: Sample that uses VK_NV_cluster_acceleration_structure to animate meshes for ray tracing

Sample that uses VK_NV_cluster_acceleration_structure to animate meshes for ray tracing - nvpro-samples/vk_animated_clusters

github.com

Highlighting one of the key contributions in MaterialX v1.39.2, Masuo Suzuki at NVIDIA contributed the Chiang Hair BSDF, seen below in NVIDIA RTX, which opens the door to the authoring of cross-platform, customizable hair shading models in MaterialX and OpenUSD. github.com/AcademySoftw...

Wrote a blog post about my development process and the tools I’ve built to develop the Spark codecs: ludicon.com/castano/blog...

Made good progress with gatling lately, and one of the new features is graphical tests. They primarily run on GitHub Actions using Mesa lavapipe (supports ray tracing). Thresholds are specified as USD render settings, diff images are uploaded as artifacts (1/4)

Hello 🦋 community!