Autodesk’s Roland Reyer compares Arnold’s two denoisers explaining uses cases for each.

Many renderers are using denoisers to clean up output images thereby speeding up rendering. Arnold recently added the Optix Denoiser allowing users to clean up images on the GPU using Nvidia’s deep learning based denoiser. Arnold, however, has not one but two of them: it has a super fast and interactive one in OptiX, but it also has a batch denoiser. So which is better and which should you use?

OptiX Denoise

Autodesk Technical Specialist Roland Reyer shows how to use both and where the advantages lie in each. The Nvidia OptiX denoise system is really fast but only works on Nvidia hardware. OptiX also will give different results between frames. If you are rendering an animation you might find that lights and reflections or other things might flicker in the scene, so it has no temporal stability between images. One other drawback to OptiX is that it can only clean up the one beauty pass.

Arnold Denoise

By contrast, the Arnold batch denoiser is statistically based and can denoise any AOV as well as the beauty pass. The Arnold Denoise system is also temporally stable, so you can get nice results while rendering animations. Arnold’s denoise solution is a tad bit slower than OptiX, but it does run on both the GPU and the CPU which makes it more suitable for production work.