6.2.6 Post Denoiser attributes

The Post Denoiser is a tool to reduce noise for images rendered with Iray for Maya 2.0 using a deep-learning based noise filter. This approach is different from the  Degrain Filtering which is in the Post Effect tab of the Render Settings window. While the classic degraining filter can provide a moderate improvement in perceived image quality, the Deep Learning-based denoiser typically provides more drastic changes.
While it is possible to enable both methods at the same time, this is not recommended and can lead to unsatisfactory results.
The Deep Learning-based denoising filter is only available when running on GPU hardware, since the inferencing step of Deep Learning systems is impractical to execute on CPUs. Also note that the additional memory required for denoising might exhaust device memory if almost all available memory is already in use by the renderer. In this case, the whole postprocessing system will fall back to CPU in order to preserve device memory, in consequence disabling denoising. Note especially that image resolution has a large impact on memory consumption of this denoiser.
It is not recommended to use the Post Denoiser in combination with tile rendering.
Small details like metallic paint can be eliminated by the Post Denoiser.

Iray Common Post Denoiser UI
Production Mode
Enables the Post Denoiser when using the batch render or command line render
The Post Denoiser is not available
Turns the Post Denoiser on. Only the denoised image is written.
Turns the Post Denoiser on. Iray writes the regular and the denoised image.
Available IPR
Turns the Post Denoise on and makes it available for the use in IPR. By itself, this option does not cause any changes in the output image.
it just triggers generation of all additional data needed for denoising to make sure it is available in case denoising is enabled later during progressive rendering. If set to true, this option may incur a small memory and performance overhead and should be set to false if denoising is not desired.
Enable IPR
If set, the denoiser will process the rendered image. If the attribute Available in IPR is not set, this option has no effect. It is not necessary to re-start progressive rendering of an image when changing this option. Turn this attribute on or off will show the resulting image in the Render View.
Start Iteration (IPR)
If the denoiser is enabled, this option will prevent denoising of the first few iterations, with the value specified in this option being the first denoised iteration. This can prevent the denoiser's performance overhead from impacting interactivity e.g. when moving the camera. Additionally, the first few iterations are often not suitable as input for the denoiser due to insufficient convergence, leading to unsatisfactory results.