Modifiers: every modifier now copies mesh settings, fixing texture space issues

Modifier stack evaluation would copy mesh settings other than mesh topology
automatically, outside of the individual modifier evaluation. This leads to hard
to understand code, and makes it unclear which settings are available in following
modifiers, and which only after the entire stack is evaluated.

Now every modifier is responsible to ensure the mesh it outputs preserves materials,
texture space and other settings, or alters them as needed.

Fixes T64739: incorrect texture space for various modifiers

Differential Revision: https://developer.blender.org/D5808

1 files changed, 10 insertions, 3 deletions

diff --git a/source/blender/blenkernel/BKE_mesh.h b/source/blender/blenkernel/BKE_mesh.h
index af40eef6ab5..b60702269a4 100644
--- a/source/blender/blenkernel/BKE_mesh.h
+++ b/source/blender/blenkernel/BKE_mesh.h
@@ -78,12 +78,18 @@ struct BMesh *BKE_mesh_to_bmesh(struct Mesh *me,
                                 const bool add_key_index,
                                 const struct BMeshCreateParams *params);
 
-struct Mesh *BKE_mesh_from_bmesh_nomain(struct BMesh *bm, const struct BMeshToMeshParams *params);
+struct Mesh *BKE_mesh_from_bmesh_nomain(struct BMesh *bm,
+                                        const struct BMeshToMeshParams *params,
+                                        const struct Mesh *me_settings);
 struct Mesh *BKE_mesh_from_bmesh_for_eval_nomain(struct BMesh *bm,
-                                                 const struct CustomData_MeshMasks *cd_mask_extra);
+                                                 const struct CustomData_MeshMasks *cd_mask_extra,
+                                                 const struct Mesh *me_settings);
 
 struct Mesh *BKE_mesh_from_editmesh_with_coords_thin_wrap(
-    struct BMEditMesh *em, const struct CustomData_MeshMasks *data_mask, float (*vertexCos)[3]);
+    struct BMEditMesh *em,
+    const struct CustomData_MeshMasks *data_mask,
+    float (*vertexCos)[3],
+    const struct Mesh *me_settings);
 
 int poly_find_loop_from_vert(const struct MPoly *poly,
                              const struct MLoop *loopstart,
@@ -107,6 +113,7 @@ void BKE_mesh_copy_data(struct Main *bmain,
                         const struct Mesh *me_src,
                         const int flag);
 struct Mesh *BKE_mesh_copy(struct Main *bmain, const struct Mesh *me);
+void BKE_mesh_copy_settings(struct Mesh *me_dst, const struct Mesh *me_src);
 void BKE_mesh_update_customdata_pointers(struct Mesh *me, const bool do_ensure_tess_cd);
 void BKE_mesh_ensure_skin_customdata(struct Mesh *me);