Each dupli is given a PersistentId which is 8 integers, 1 for each level
of recursive duplication that Blender supports. When an instance belongs
to fewer than 8 levels, the id is padded with sentinel values for the
remaining levels. For example, a 2 level dupli may have a persistent id
like:`[7, 4, INT_MAX, INT_MAX, INT_MAX, INT_MAX, INT_MAX, INT_MAX]`
When calculating the instance's `random_id` we were considering all 8
values of the Persistent Id which is unnecessary and wasteful. Now we
only use the minimal values necessary. This does mean that the Object
Info: Random material socket changes values from prior versions however.
This improves the performance of the viewport in some instancing
scenes by roughly 4-6%.
Co-authored-by: Bastien Montagne <mont29@noreply.localhost>
Pull Request: https://projects.blender.org/blender/blender/pulls/145150
d26a79b144