Temporal Denoising Toolkit for Blender

Blender compositing node group for temporal denoising of animations.

This is used to reduce the flickering or shimmering between frames of an animation.

This node group requires multi-layer EXR files as input containing these layers:

• Vector (required)
• Denoising Data (recommended)
• Environment (when applicable)

The node group will intelligently combine multiple frames of animation and reduce temporal noise across the frames. This will allow the the spatial denoiser (OpenImageDenoise) to achieve a higher quality result.

Version History

V1.0, 6th May 2023, for Blender 3.5+

• Initial release

Additional Info

• Check out my YouTube video for more details, including a temporal denoising comparison between OptiX and my node group.
• Create a Blender project for compositing, and append the Temporal Denoising node group (this download).
• Load your EXR image sequence in the compositor, and duplicate twice. Set the Offset value so that the current, previous and next frames can be accessed. Connect the Combined and Vector layers to the Temporal Denoising node group.
• Use the Hue/Saturation/Value Threshold values to restrict blending of dissimilar areas (shadow/non-shadow or simply where the lighting changes significantly). A threshold value of 1.0 disables that threshold. Often the Value Threshold must be set quite low (e.g. 0.05) to avoid shadow problems. (Which is counter productive for reducing temporal/spatial noise.)
• The Max Weight setting controls the mix balance between current frame and the next/previous frames. The default value of 0.3 indicates that the next/previous frames can have up-to 30% contribution (each), and the current frame will have at-least 40%. You could use 33.3% for an equal weighting, or say 25%/25%/50% to reduce any artefacts.
• You have the option of performing spatial denoising (Denoise node) before or after temporal denoising.
• Best results will be achieved if you are able to render Shadows separately. It may be possible to do this using the Shadow Catcher in simple scenes.
• The Temporal Denoising (Debug) node group has tools for visualising motion vectors.
• At this point the node group is designed for denoising across three frames, but it could be extended to work across more frames.