Multires: Subdivide Simple and Subdivide Linear

This introduces two alternative subdivision modes that generates
displacement on the grids that look as Simple subdivisions but while
using the Catmull-Clark subdivision type in the modifier. This way,
Simple and Catmull-Clark subdivision can be combined when creating new
levels if needed, for example, to sculpt hard surface objects.

Subdivide simple smooths the sculpted data when creating a new
subdivision level. Subdivide linear also preserves the sharpness
in the sculpted data.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D7415

1 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/blenkernel/intern/multires.c b/source/blender/blenkernel/intern/multires.c
index 317c59182ed..d79dbbb7d32 100644
--- a/source/blender/blenkernel/intern/multires.c
+++ b/source/blender/blenkernel/intern/multires.c
@@ -2234,7 +2234,14 @@ void multiresModifier_sync_levels_ex(Object *ob_dst,
   }
 
   if (mmd_src->totlvl > mmd_dst->totlvl) {
-    multiresModifier_subdivide_to_level(ob_dst, mmd_dst, mmd_src->totlvl);
+    if (mmd_dst->simple) {
+      multiresModifier_subdivide_to_level(
+          ob_dst, mmd_dst, mmd_src->totlvl, MULTIRES_SUBDIVIDE_SIMPLE);
+    }
+    else {
+      multiresModifier_subdivide_to_level(
+          ob_dst, mmd_dst, mmd_src->totlvl, MULTIRES_SUBDIVIDE_CATMULL_CLARK);
+    }
   }
   else {
     multires_del_higher(mmd_dst, ob_dst, mmd_src->totlvl);