Blender Git Loki

Fix T81729: Cycles object color not updating for instancers

Caused by rBe65c78cd43aa.

Since above commit, only geometry and lights received the update,
previous to this check an instancer would receive that is well (in case
of 'is_updated_shading').

Now check for an instancer (checking OB_DUPLI via ob.is_instancer()) and
do an update then as well.

Reviewers: brecht

Maniphest Tasks: T81729

Differential Revision: https://developer.blender.org/D9222