In addition to many fixes, this build introduces some unique optimizations that help with guiding CPU expenditure, speeding rendering especially in interiors, where light enters through windows, and with directional light sources like the sun. It is not possible to quote a specific speedup to expect, since it is very scene dependent, but here is an example comparing 20.8 vs 20.13:
Along with this and some other optimizations having to do with materials, the improvements are substantial — here is a comparison showing material improvements from 20.7 vs 20.13:
Changes in Bella GUI are mostly about improving stability, there were some rare crash scenarios found and fixed.
In the Rhino plugin, we have implemented a caching system to improve performance of material previews, and switching between materials. We have also added support for the Rhino ground plane’s mapping parameters, and done much work on translation of Rhino lights, such that the outputs should be in the ballpark to what you get from cycles, irrespective of the chosen document units, and even when you have scaled the light.
In the Maya plugin we have improved stopping of export/render by the ESC key, and added feedback for render status in IPR. We have also added some commands for exporting BSX/BSZ files from mel, including sequences, in order to render animation outside Maya.