Houdini 20.0 Rendering

NVIDIA OptiX denoiser

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NVIDIA’s OptiX AI-Accelerated Denoiser uses deep learning to remove noise and “fireflies” from a rendered image. It is useful for getting a higher-quality preview of what a converged image will look like so you can make lighting decisions faster.

  • The NVIDIA OptiX denoiser requires an NVIDIA GPU with Kepler architecture or better.

  • The denoiser is not available on macOS.

How to

To...Do this

Use the denoiser in the Render View

Turn on the Denoise button in the toolbar at the top of the render view. (This button is disabled if the plugin is not installed.)

In the Render View, the denoiser always uses the “basecolor” image plane (if it exists) as the albedo input.

Use the denoiser in Mantra

In the parameter editor for the Mantra render node, click the Images tab, then click the Output sub-tab. Click the drop-down menu button next to the Pixel filter field and choose “NVIDIA OptiX Denoiser” (sets the field to denoise optix).

In the Pixel filter field you can optionally specify an image plane to use as the albedo input to the denoiser with the -a option, for example:

denoise optix -a mydiffuse

Choose which GPU to use

If you have more than one GPU in your computer, you can specify which one to use for denoising.

  1. Run the following in command-line to see OptiX-capable devices listed in order:

    > hgpuinfo -o
  2. Set the $HOUDINI_NVIDIA_OPTIX_DEVICENUMBER environment variable to the desired device ID, starting from 0 (for example, 0 to use the first device, 1 to use the second device).


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