[Bf-blender-cvs] [7e678c30964] blender-v2.93-release: Fix T87165: Join geometry node doesn't copy instance IDs

[Hans Goudey]

Commit: 7e678c30964c4c0d9d2c020f25e8ac717211c208
Author: Hans Goudey
Date:   Tue Apr 27 23:37:27 2021 -0500
Branches: blender-v2.93-release
https://developer.blender.org/rB7e678c30964c4c0d9d2c020f25e8ac717211c208

Fix T87165: Join geometry node doesn't copy instance IDs

This makes motion blur work incorrectly. With a similar fix to
rBf2d70c02f88cc00, just copy over the instance IDs in this case.

===================================================================

M	source/blender/nodes/geometry/nodes/node_geo_join_geometry.cc

===================================================================

diff --git a/source/blender/nodes/geometry/nodes/node_geo_join_geometry.cc b/source/blender/nodes/geometry/nodes/node_geo_join_geometry.cc
index 52512769a47..77d2b0df2a9 100644
--- a/source/blender/nodes/geometry/nodes/node_geo_join_geometry.cc
+++ b/source/blender/nodes/geometry/nodes/node_geo_join_geometry.cc
@@ -248,8 +248,9 @@ static void join_components(Span<const InstancesComponent *> src_components, Geo
     const int size = component->instances_amount();
     Span<InstancedData> instanced_data = component->instanced_data();
     Span<float4x4> transforms = component->transforms();
+    Span<int> ids = component->ids();
     for (const int i : IndexRange(size)) {
-      dst_component.add_instance(instanced_data[i], transforms[i]);
+      dst_component.add_instance(instanced_data[i], transforms[i], ids[i]);
     }
   }
 }