For those who don’t know the tool: Arnold is a renderer from Autodesk for final-frame lighting and lookdev. It plugs into Maya, 3ds Max, Cinema 4D, Houdini and Katana.

Splats enter the renderer

Arnold 7.5.2 adds support for rendering 3D Gaussian Splatting data. That gives captured scenes and objects another route into offline rendering, instead of staying parked in viewers, real-time tools or half-temporary conversion scripts (Which have been temporary and unchanged since the first time they worked. Yes, we’ve all been there.

The main ingest route uses the existing Points node. It can load 3DGS data from an imported PLY file, or import the data directly as a per-point array. That keeps splats close to point-based workflows, which is sensible and pleasantly unfancy.

The update also adds preliminary support for the new Gaussian Splat schema introduced in OpenUSD 26.03. The ParticleField3DGaussianSplat schema represents the original 3D Gaussian Splats technique as a ParticleField. In Arnold 7.5.2, that makes it possible to render 3DGS data stored in USD files.

Relighting, the useful bit

The new Gaussian Splat Shader adjusts the lighting of imported splats. Splats can be relit entirely with scene lights, which is teh part that matters once a capture has to sit inside an actual shot instead of looking lovely in isolation.

That puts 3DGS closer to normal lighting work. The splat is still a splat, with all the data-shape caveats that come with the technique, but the renderer now has a specific shader for controlling its appearance in an Arnold scene.

For Gaussian splatting workflows, this also moves the format closer to the boring middle of production. Boring is good. Boring means fewer emergency exporters named final_final_v12.

NPR gets more knobs

Toon and non-photorealistic rendering also get new nodes. Tone Zones splits RGB lighting into up to eight discrete brightness bands. Each band can be tinted independently or rendered as a separate AOV.

Shader to RGBA evaluates lighting for a surface shader, including OpenPBR Surface, and outputs RGBA data for use in a shading tree. Those RGBA values can feed into a Ramp shader for non-photorealistic rendering.

The result is more control over cel-style bands and shader-driven looks inside the renderer. That is good news for artists who need graphic shading without turning the node graph into a small regional train map.

USD lights behave better

Arnold 7.5.2 supports the current UsdLux standard for USD lights. Cone shaping controls and IES photometric profiles now work on all light types, including cylinder, disk, quad and mesh lights. Previously, that support was limited to spot and sphere lights.

That change is less glamorous than splats, but production lighting often lives in these tiny consistency details. A light standard that behaves differently per light type is how pipelines acquire folklore.

Denoising and mesh updates

Noice, the native denoiser, gets quality improvements. Denoised images should come out sharper with fewer pixel artifacts. That is the kind of update nobody celebrates until a supervisor zooms into a dark corner at 300 percent.

GPU rendering also gets faster scene updates, especially when artists edit meshes interactively. Loading meshes from PLY files is claimed to be about 1.2x to 1.4x faster.

System requirements list Windows 10 or newer, Linux with glibc 2.28 or newer, and macOS 12.0 or newer. GPU rendering runs on Windows and Linux only and requires a compatible NVIDIA GPU.

Plugins and cloud chores

The integration plugins have been updated for this release. Listed versions are MAXtoA 5.9.3 for 3ds Max, C4DtoA 4.9.2 for Cinema 4D, HtoA 6.5.2 for Houdini, KtoA 4.5.2 for Katana and MtoA 5.6.2 for Maya.

Flow Render now supports scenes larger than 5GB. Scene uploads are automatically validated, and files without a camera or defined render outputs generate a failure message. That sounds like admin plumbing, and taht is exactly why it matters when an artist has already gone home.

Flow Render remains free for all Arnold users for up to 40 hours of rendering per month. The cloud service first arrived with Arnold 7.5.1 as a tech preview with 2,400 render minutes per user per month.

https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_core_7520_html
https://help.autodesk.com/view/ARNOL/ENU/

The post Arnold 7.5.2 Adds Gaussian Splats first appeared on DIGITAL PRODUCTION and was written by Bela Beier.

Autodesk has released Arnold 7.5.1. The headline feature is Flow Render, a new cloud rendering tech preview that gives Arnold users 2,400 render minutes per month for testing. Beneath that, and arguably more useful once actual shots arrive, the update also fixes a long-standing gap in volume AOVs, adds MIKKTSpace normal mapping, and squeezes some extra CPU performance out of Windows.

Flow Render is here, with sensible limits and no magic involved

The loudest part of Arnold 7.5.1 is Flow Render, Autodesk’s new cloud rendering tech preview for Arnold. During the preview, users get 2,400 render minutes per month. That is 40 hours, which is enough to test the service properly, but not enough to start behaving like a streaming platform.

The basic idea is simple: submit Arnold jobs to the cloud, free up local machines, and run more variations in parallel. Autodesk pitches this as a way to speed up rendering, look development, and simulation work without tying up workstations all day.

Flow Render requires an Autodesk account login, because of course it does. Submission happens through the Arnold plugins. Autodesk lists support for Houdini, 3ds Max, Cinema 4D, and Maya, while Katana support is still listed as coming soon. The backend runs on Autodesk Platform Services through the Flow Graph Engine API, which handles the cloud storage and compute side.

Autodesk says Flow Render is aimed at everyone from larger VFX and animation studios to freelance 3D and FX artists. That is the official line. In practice, the current limits matter more than the broad target group wording. A single task can run for up to 12 hours. Users can run up to 10 tasks simultaneously, subject to service-level limits. Task data is stored for 30 days.

So yes, it is cloud rendering. No, it is not a bottomless sky-farm that will lovingly absorb every pipeline problem. At this stage it looks more like a practical overflow and evaluation option, which is honestly a lot more believable.

The more important production news is in Arnold itself

The stronger part of this release is the renderer update. Arnold 7.5.1 finally adds proper custom AOV support for volume shaders. The aov_write_rgb, aov_write_float, and aov_write_rgba shader nodes now work in volume networks just as they do for surface shaders. Previously, Arnold silently ignored them in volume contexts, which is the kind of workflow detail that tends to waste time very efficiently.

Autodesk says the volume raymarcher now collects AOV closures at each step and integrates them using Beer-Lambert weighting, so the resulting outputs remain physically consistent. Flat formats such as EXR and TIFF are supported, as is deep EXR. There is a cost, naturally. Autodesk notes roughly 16% overhead with two active volume AOVs at fine step sizes. Useful feature, non-zero bill. Reality remains intact.

Arnold 7.5.1 also adds a new tangent_space_type parameter to the normal_map shader, bringing support for MIKKTSpace normal mapping. The previous mode stays in place as standard, while the new mikk mode uses MIKKTSpace-generated normal, tangent, and bitangent data from DCC tools such as 3ds Max. That should reduce shading mismatches between applications, which is not glamorous, but is exactly the kind of boring improvement people end up appreciating.

Windows users also get CPU render optimizations. Autodesk says most scenes render faster, though not all. The examples in the release notes show a 1.16x speedup for the OpenPBR shader ball, 1.08x for gtc-robot, 1.07x for Disney cloud, and 1.04x for ALab. Intel jungle ruins stays at 1.00x, apparently choosing not to participate.

There is one incompatible rendering change worth noting. Arnold now correctly supports the exponent parameter in the OSL generalized_schlick_bsdf closure for both reflection and transmission. Scenes using non-default exponent values or heavy transmission may therefore render differently. Technically correct, slightly annoying, very Arnold-point-release.

The bug-fix list covers GPU artifacts, IPR crashes, incorrect volume mipmap selection, polymesh crashes, Hydra update problems, and several USD-related issues. So this is a proper point release: one shiny cloud headline, several genuinely useful renderer fixes, and a pile of smaller changes that will matter most to the people who have already been burned by them.

Links

Autodesk Arnold 7.5.1 release notes:
https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_core_7510_html

Autodesk Flow Render FAQ:
https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_core_rendering_ac_flow_render_faq_html

The post Arnold 7.5.1 comes with Flow Render Tech, Volume AOVs, and MIKKTSpace first appeared on DIGITAL PRODUCTION and was written by Bela Beier.