source/blender/blenkernel/intern/mesh.cc

@@ -1585,6 +1585,11 @@ bool BKE_mesh_minmax(const Mesh *me, float r_min[3], float r_max[3])
   return true;
 }
 
+void Mesh::bounds_set_eager(const blender::Bounds<float3> &bounds)
+{
+  this->runtime->bounds_cache.ensure([&](blender::Bounds<float3> &r_data) { r_data = bounds; });
+}
+
 void BKE_mesh_transform(Mesh *me, const float mat[4][4], bool do_keys)
 {
   MutableSpan<float3> positions = me->vert_positions_for_write();

source/blender/editors/sculpt_paint/sculpt.cc

@@ -5549,9 +5549,9 @@ void SCULPT_flush_update_step(bContext *C, SculptUpdateType update_flags)
       /* When sculpting and changing the positions of a mesh, tag them as changed and update. */
       BKE_mesh_tag_positions_changed(mesh);
       /* Update the mesh's bounds eagerly since the PBVH already has that information. */
-      mesh->runtime->bounds_cache.ensure([&](Bounds<float3> &r_bounds) {
-        BKE_pbvh_bounding_box(ob->sculpt->pbvh, r_bounds.min, r_bounds.max);
-      });
+      Bounds<float3> bounds;
+      BKE_pbvh_bounding_box(ob->sculpt->pbvh, bounds.min, bounds.max);
+      mesh->bounds_set_eager(bounds);
     }
   }
 }

source/blender/geometry/intern/mesh_primitive_cuboid.cc

@@ -418,6 +418,9 @@ Mesh *create_cuboid_mesh(const float3 &size,
     calculate_uvs(config, mesh, uv_id);
   }
 
+  const float3 bounds = size * 0.5f;
+  mesh->bounds_set_eager({-bounds, bounds});
+
   return mesh;
 }
 

source/blender/makesdna/DNA_mesh_types.h

@@ -16,6 +16,7 @@
 /** Workaround to forward-declare C++ type in C header. */
 #ifdef __cplusplus
 
+#  include "BLI_bounds_types.hh"
 #  include "BLI_math_vector_types.hh"
 
 namespace blender {
@@ -261,6 +262,9 @@ typedef struct Mesh {
    */
   blender::Span<MLoopTri> looptris() const;
 
+  /** Set cached mesh bounds to a known-correct value to avoid their lazy calculation later on. */
+  void bounds_set_eager(const blender::Bounds<blender::float3> &bounds);
+
   /**
    * Cached information about loose edges, calculated lazily when necessary.
    */

source/blender/nodes/geometry/nodes/node_geo_mesh_primitive_grid.cc

@@ -148,6 +148,9 @@ Mesh *create_grid_mesh(const int verts_x,
 
   mesh->loose_edges_tag_none();
 
+  const float3 bounds = float3(size_x * 0.5f, size_y * 0.5f, 0.0f);
+  mesh->bounds_set_eager({-bounds, bounds});
+
   return mesh;
 }