Arnold 7.5.2 Adds 3D Gaussian Splat Rendering and Relighting via New Gaussian Splat Shader
Michael Rubloff
Autodesk has released Arnold 7.5.2, adding native support for rendering Gaussian Splatting scenes. The implementation routes through the existing Points node. Set points.mode to gaussian and point file_name at a .ply, and uses a new gaussian_splat_shader node to control appearance and relighting.
The shader exposes two components. Emission, which reproduces the original SH-color unlit look from capture, and diffuse, which enables path traced relighting. By default splats render emission only. Increasing the diffuse weight causes them to respond to scene lights.
Arnold 7.5.2 also picks up preliminary support for the ParticleField3DGaussianSplat schema introduced in OpenUSD 26.03, making it possible to render GS data authored as USD prims directly. The USD path is flagged as preliminary in keeping with the spec's own recent status. Work establishing what USD native GS prims should look like inside a DCC had been underway before the spec landed, houdini-gsplat demonstrated a ParticleField3DGaussianSplat schema implementation inside Houdini Solaris earlier this year.
The release also adds two NPR shading nodes. tone_zones splits lighting into up to eight discrete brightness bands for cel-shading, with independent tint and mask outputs per zone and the ability to chain nodes for further subdivision. shader_to_rgba evaluates a full surface shader, including OpenPBR Surface, and outputs the result as RGBA, with separate direct and indirect outputs and a per light group filter. Both run on CPU and GPU. out_indirect is not yet available on GPU.
Noice, Arnold's standalone denoiser, fixes two issues. Images could be over blurred even with sufficient sample counts, and occasional black pixel artifacts could appear in output. The variance parameter on the Noice imager has been renamed filter_strength (the old name is kept as a synonym; --variance/-v CLI flags are retained as aliases for --filter_strength/-k). GPU scene updates are up to 43% faster for interactive mesh edits.
Linux now requires glibc 2.28+ (RHEL/Rocky 8 equivalent, up from glibc 2.17), and macOS now requires 12.0 (up from 11.0). Arnold 7.5.2 also updates OSL to 1.14.2.0, MaterialX to 1.39.5, and OpenColorIO to 2.5.2.
