GI (Global Illumination) handling in Terragen
Scenes that utilize Global Illumination (GI) are handled automatically by our farm. If GI is detected in a scene file, we automatically render and store a GI cache prior to the final render pass. After completion of the cache, the job is re-submitted to the farm for the final pass. We deliver the GI pass completion percentage to our client GUI, so you know how far along the job is. GI caches for a tiled still are rendered by only one node, so keep that in mind if you’re concerned about performance. GI caches for frame ranges are rendered on multiple nodes governed by job power. If you wish to have our system render a sparse GI cache for you, you may do so by specifying an alternate frame list in the “GI Frame List” field. That field displays automatically when our agent detects the use of GI in your scene file. The default is to render and store a GI cache for each final output frame, but you can change this by modifying the GI Frame List entry. For example, if your scene has 100 final frames, the Frame List field may say “1:100”. If you wanted our system to render a GI pass for every 10 frames of that range, you would enter “1:100 by 10” in the GI Frame List field. The GI Frame List field accepts all the input formatting options that the Frame List field supports, so “1:100:10”, “1-100-10”, “1 to 100 by 10”, and others all mean the same thing.
We still allow (and automatically detect) if you pre-render a GI cache for your scene and submit it with the job. We only create a GI cache if your scene uses GI but was uploaded without a cache. All artist controls remain untouched, so you still control how many frames to blend across a range.
At present, Terragen 4 “Easy Clouds” have their own GI structures, and that data is not cacheable. Please keep this in mind if you are rendering a still image using TG4 Easy Clouds. We recommend making any setting change that will cause our system to not tile split the render.