The options available in this tab allow you to set the behavior for the UHD Cache GI Solver.

UI Path: ||Render settings window|| > Corona > Secondary GI: UHD Cache tab

Preset – This is a list of presets for most common scenarios, still images, and animated sequences.

Available presets are:

Still frame (fast precomputation) – This configuration with short precomputation works great in still frames but might flicker in animations.
Animation (flicker-free) – This configuration with longer precomputation aims at eliminating flickering in animations.

Precision – This value is a quality-time tradeoff for the UHD Cache. Lower values result in fast precomputation but can increase bias and flickering. Higher values give more precise, flicker-free results with longer precomputation. High values should be avoided, as they also lower the success rate of the cache and make it less efficient during the rendering phase.

Show previsualization – Precomputation is displayed during the rendering process when this checkbox is enabled.

Precomputation – Determines how the UHD cache is obtained for rendering.

Available precomputation modes are:

Calculate from scratch – The cache is calculated independently for each frame in a precomputation pass when using this mode.
Load from file – The cache is loaded from a specified file instead of being computed. Good for animations as it prevents flickering.
Load from file + append – The cache is first loaded from the specified file, and then the precomputation pass runs on top of it when using this mode. The loaded and computed caches are merged. Good for animation precomputation (when ran e.g. every 30 frames).

After render – When set to Save, the UHD/4K cache is saved to the specified file after rendering, possibly overwriting it.

Filename – Here, you can specify the path where the cache file will be saved to or loaded from.