Using the Built-In and Optix Denoiser
1. Using NVIDIA® OptiX™
To use the Optix Denoiser, switch to the Display Settings tab and enable the Optix Denoiser checkbox. Two additional channels will be enabled, Normals and Raw Diffuse Color, that will guide the Optix Denoiser to properly clear the remaining noise from the image.
It is also possible to render the image without having Optix enabled. In this case, Optix will remove the remaining noise without using the two render channels that will lead to a blurry image.
Note: There are no options for Optix.
Requirements: Your system needs to have an NVIDIA GPU in order for Optix to work. In this case, the option will not be available in the Display Settings.
Tip: For large images, it is best to enable Optix after the render has been completed as this will make the rendering process slower. Enable Normals and Raw Diffuse Color before starting a render and once the image has finished use the Optix checkbox to denoise the image.
2. Using the Built-in Denoiser
The Built-in denoiser works differently than Optix. To enable it, switch to the Channels tab and enable the Denoiser Channel from the list by clicking on the checkbox next to it.
Now, start rendering your project and once finished, select Denoise from the Active Channel drop-box. The built-in denoiser has two options to help you control the amount of noise removal. These options can be found right below the Channels list.
Strength: adjusts the overall noise removal of the image.
Details: Higher values will try to keep most of the details of the original image.
Requirements: The Built-in denoiser does not depend on the hardware but it is only available for the Presto (MC) engine