[Bf-blender-cvs] [58f1e62871c] master: Geometry Nodes: Parallelize deleting vertex group

[Hans Goudey]

Commit: 58f1e62871cc9f4be418c4f2397ae6bb86318d15
Author: Hans Goudey
Date:   Wed Jan 4 12:19:58 2023 -0500
Branches: master
https://developer.blender.org/rB58f1e62871cc9f4be418c4f2397ae6bb86318d15

Geometry Nodes: Parallelize deleting vertex group

Since 78f28b55d39288926634, allocating on multiple threads is much
faster, making it a nice improvement to parallelize vertex group
operations. This patch adds multi-threading when removing a
vertex group from the "Remove Named Attribute" node.

On a Ryzen 3700x:
Before: `(Average: 15.6 ms, Min: 15.0 ms)`
After: `(Average: 8.1 ms, Min: 7.6 ms)`

Differential Revision: https://developer.blender.org/D16916

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

M	source/blender/blenkernel/intern/geometry_component_mesh.cc

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

diff --git a/source/blender/blenkernel/intern/geometry_component_mesh.cc b/source/blender/blenkernel/intern/geometry_component_mesh.cc
index 87ddb76171e..ac19fb43568 100644
--- a/source/blender/blenkernel/intern/geometry_component_mesh.cc
+++ b/source/blender/blenkernel/intern/geometry_component_mesh.cc
@@ -1117,15 +1117,18 @@ class VertexGroupsAttributeProvider final : public DynamicAttributesProvider {
       return true;
     }
 
-    for (MDeformVert &dvert : mesh->deform_verts_for_write()) {
-      MDeformWeight *weight = BKE_defvert_find_index(&dvert, index);
-      BKE_defvert_remove_group(&dvert, weight);
-      for (MDeformWeight &weight : MutableSpan(dvert.dw, dvert.totweight)) {
-        if (weight.def_nr > index) {
-          weight.def_nr--;
+    MutableSpan<MDeformVert> dverts = mesh->deform_verts_for_write();
+    threading::parallel_for(dverts.index_range(), 1024, [&](IndexRange range) {
+      for (MDeformVert &dvert : dverts.slice(range)) {
+        MDeformWeight *weight = BKE_defvert_find_index(&dvert, index);
+        BKE_defvert_remove_group(&dvert, weight);
+        for (MDeformWeight &weight : MutableSpan(dvert.dw, dvert.totweight)) {
+          if (weight.def_nr > index) {
+            weight.def_nr--;
+          }
         }
       }
-    }
+    });
     return true;
   }