7 files changed, 49 insertions, 4 deletions

diff --git a/source/blender/blenkernel/BKE_subdiv.h b/source/blender/blenkernel/BKE_subdiv.h
index 96a79d753cf..92da909b2ae 100644
--- a/source/blender/blenkernel/BKE_subdiv.h
+++ b/source/blender/blenkernel/BKE_subdiv.h
@@ -204,6 +204,9 @@ void BKE_subdiv_exit(void);
 /* NOTE: uv_smooth is eSubsurfUVSmooth. */
 eSubdivFVarLinearInterpolation BKE_subdiv_fvar_interpolation_from_uv_smooth(int uv_smooth);
 
+eSubdivVtxBoundaryInterpolation BKE_subdiv_vtx_boundary_interpolation_from_subsurf(
+    int boundary_smooth);
+
 /* =============================== STATISTICS =============================== */
 
 void BKE_subdiv_stats_init(SubdivStats *stats);
diff --git a/source/blender/blenkernel/intern/multires_subdiv.c b/source/blender/blenkernel/intern/multires_subdiv.c
index fc092d3ccce..73ef623fbfd 100644
--- a/source/blender/blenkernel/intern/multires_subdiv.c
+++ b/source/blender/blenkernel/intern/multires_subdiv.c
@@ -40,7 +40,8 @@ void BKE_multires_subdiv_settings_init(SubdivSettings *settings, const MultiresM
   settings->is_adaptive = true;
   settings->level = settings->is_simple ? 1 : mmd->quality;
   settings->use_creases = (mmd->flags & eMultiresModifierFlag_UseCrease);
-  settings->vtx_boundary_interpolation = SUBDIV_VTX_BOUNDARY_EDGE_ONLY;
+  settings->vtx_boundary_interpolation = BKE_subdiv_vtx_boundary_interpolation_from_subsurf(
+      mmd->boundary_smooth);
   settings->fvar_linear_interpolation = BKE_subdiv_fvar_interpolation_from_uv_smooth(
       mmd->uv_smooth);
 }
diff --git a/source/blender/blenkernel/intern/subdiv.c b/source/blender/blenkernel/intern/subdiv.c
index fe1dd3835fd..f1cde39f657 100644
--- a/source/blender/blenkernel/intern/subdiv.c
+++ b/source/blender/blenkernel/intern/subdiv.c
@@ -72,6 +72,19 @@ eSubdivFVarLinearInterpolation BKE_subdiv_fvar_interpolation_from_uv_smooth(int
   return SUBDIV_FVAR_LINEAR_INTERPOLATION_ALL;
 }
 
+eSubdivVtxBoundaryInterpolation BKE_subdiv_vtx_boundary_interpolation_from_subsurf(
+    int boundary_smooth)
+{
+  switch (boundary_smooth) {
+    case SUBSURF_BOUNDARY_SMOOTH_PRESERVE_CORNERS:
+      return SUBDIV_VTX_BOUNDARY_EDGE_AND_CORNER;
+    case SUBSURF_BOUNDARY_SMOOTH_ALL:
+      return SUBDIV_VTX_BOUNDARY_EDGE_ONLY;
+  }
+  BLI_assert(!"Unknown boundary smooth flag");
+  return SUBDIV_VTX_BOUNDARY_EDGE_ONLY;
+}
+
 /* ================================ SETTINGS ================================ */
 
 static bool check_mesh_has_non_quad(const Mesh *mesh)
diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index d7a41b5cb3b..fa2f54c7aa0 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -179,13 +179,19 @@ typedef enum {
   SUBSURF_UV_SMOOTH_ALL = 5,
 } eSubsurfUVSmooth;
 
+typedef enum {
+  SUBSURF_BOUNDARY_SMOOTH_ALL = 0,
+  SUBSURF_BOUNDARY_SMOOTH_PRESERVE_CORNERS = 1,
+} eSubsurfBoundarySmooth;
+
 typedef struct SubsurfModifierData {
   ModifierData modifier;
 
   short subdivType, levels, renderLevels, flags;
   short uv_smooth;
   short quality;
-  char _pad[4];
+  short boundary_smooth;
+  char _pad[2];
 
   /* TODO(sergey): Get rid of those with the old CCG subdivision code. */
   void *emCache, *mCache;
@@ -1042,7 +1048,8 @@ typedef struct MultiresModifierData {
   char simple, flags, _pad[2];
   short quality;
   short uv_smooth;
-  char _pad2[4];
+  short boundary_smooth;
+  char _pad2[2];
 } MultiresModifierData;
 
 typedef enum {
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index 134ce15e3f2..a0a8d37fd56 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -1686,6 +1686,16 @@ static PropertyRNA *rna_def_property_subdivision_common(StructRNA *srna, const c
     {0, NULL, 0, NULL, NULL},
   };
 
+  static const EnumPropertyItem prop_boundary_smooth_items[] = {
+      {SUBSURF_BOUNDARY_SMOOTH_PRESERVE_CORNERS,
+       "PRESERVE_CORNERS",
+       0,
+       "Keep Corners",
+       "Smooth boundaries, but corners are kept sharp"},
+      {SUBSURF_BOUNDARY_SMOOTH_ALL, "ALL", 0, "All", "Smooth boundaries, including corners"},
+      {0, NULL, 0, NULL, NULL},
+  };
+
   PropertyRNA *prop;
 
   RNA_define_lib_overridable(true);
@@ -1704,6 +1714,12 @@ static PropertyRNA *rna_def_property_subdivision_common(StructRNA *srna, const c
       prop, "Quality", "Accuracy of vertex positions, lower value is faster but less precise");
   RNA_def_property_update(prop, 0, "rna_Modifier_update");
 
+  prop = RNA_def_property(srna, "boundary_smooth", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "boundary_smooth");
+  RNA_def_property_enum_items(prop, prop_boundary_smooth_items);
+  RNA_def_property_ui_text(prop, "Boundary Smooth", "Controls how open boundaries are smoothed");
+  RNA_def_property_update(prop, 0, "rna_Modifier_update");
+
   prop = RNA_def_property(srna, "subdivision_type", PROP_ENUM, PROP_NONE);
   RNA_def_property_enum_sdna(prop, NULL, type);
   RNA_def_property_enum_items(prop, prop_subdivision_type_items);
diff --git a/source/blender/modifiers/intern/MOD_multires.c b/source/blender/modifiers/intern/MOD_multires.c
index 2c6ee50d419..41188fcc907 100644
--- a/source/blender/modifiers/intern/MOD_multires.c
+++ b/source/blender/modifiers/intern/MOD_multires.c
@@ -73,6 +73,7 @@ static void initData(ModifierData *md)
   mmd->renderlvl = 0;
   mmd->totlvl = 0;
   mmd->uv_smooth = SUBSURF_UV_SMOOTH_PRESERVE_CORNERS;
+  mmd->boundary_smooth = SUBSURF_BOUNDARY_SMOOTH_ALL;
   mmd->quality = 4;
   mmd->flags |= (eMultiresModifierFlag_UseCrease | eMultiresModifierFlag_ControlEdges);
 
@@ -489,6 +490,7 @@ static void advanced_panel_draw(const bContext *UNUSED(C), Panel *panel)
   col = uiLayoutColumn(layout, false);
   uiLayoutSetEnabled(col, true);
   uiItemR(col, ptr, "uv_smooth", 0, NULL, ICON_NONE);
+  uiItemR(col, ptr, "boundary_smooth", 0, NULL, ICON_NONE);
 
   uiItemR(layout, ptr, "use_creases", 0, NULL, ICON_NONE);
   uiItemR(layout, ptr, "use_custom_normals", 0, NULL, ICON_NONE);
diff --git a/source/blender/modifiers/intern/MOD_subsurf.c b/source/blender/modifiers/intern/MOD_subsurf.c
index 7a118c6c14d..10d7b21d56f 100644
--- a/source/blender/modifiers/intern/MOD_subsurf.c
+++ b/source/blender/modifiers/intern/MOD_subsurf.c
@@ -74,6 +74,7 @@ static void initData(ModifierData *md)
   smd->levels = 1;
   smd->renderLevels = 2;
   smd->uv_smooth = SUBSURF_UV_SMOOTH_PRESERVE_CORNERS;
+  smd->boundary_smooth = SUBSURF_BOUNDARY_SMOOTH_ALL;
   smd->quality = 3;
   smd->flags |= (eSubsurfModifierFlag_UseCrease | eSubsurfModifierFlag_ControlEdges);
 }
@@ -167,7 +168,8 @@ static void subdiv_settings_init(SubdivSettings *settings,
                         1 :
                         (settings->is_adaptive ? smd->quality : requested_levels);
   settings->use_creases = (smd->flags & eSubsurfModifierFlag_UseCrease);
-  settings->vtx_boundary_interpolation = SUBDIV_VTX_BOUNDARY_EDGE_ONLY;
+  settings->vtx_boundary_interpolation = BKE_subdiv_vtx_boundary_interpolation_from_subsurf(
+      smd->boundary_smooth);
   settings->fvar_linear_interpolation = BKE_subdiv_fvar_interpolation_from_uv_smooth(
       smd->uv_smooth);
 }
@@ -471,6 +473,7 @@ static void advanced_panel_draw(const bContext *C, Panel *panel)
   uiItemR(col, ptr, "quality", 0, NULL, ICON_NONE);
 
   uiItemR(layout, ptr, "uv_smooth", 0, NULL, ICON_NONE);
+  uiItemR(layout, ptr, "boundary_smooth", 0, NULL, ICON_NONE);
   uiItemR(layout, ptr, "use_creases", 0, NULL, ICON_NONE);
   uiItemR(layout, ptr, "use_custom_normals", 0, NULL, ICON_NONE);
 }