Mesh: Add Auto Smooth option to Shade Smooth operator

Add a property to the **Shade Smooth** operator to quickly enable the Mesh `use_auto_smooth` option.

The `Angle` property is exposed in the **Adjust Last Operation** panel to make it easy to tweak on multiple objects without having to go to the Properties editor.

The operator is exposed in the `Object` menu and `Object Context Menu`.

=== Demo ===

{F13066173, size=full}

Regarding the implementation, there are multiple ways to go about this (like making a whole new operator altogether), but I think a property is the cleanest/simplest.

I imagine there are simpler ways to achieve this without duplicating the `use_auto_smooth` property in the operator itself (getting it from the Mesh props?), but I couldn't find other operators doing something similar.

Reviewed By: #modeling, mont29

Differential Revision: https://developer.blender.org/D14894

release/scripts/startup/bl_ui/space_view3d.py

@@ -2346,6 +2346,7 @@ class VIEW3D_MT_object(Menu):
         layout.separator()
 
         layout.operator("object.shade_smooth")
+        layout.operator("object.shade_smooth", text="Shade Auto Smooth").use_auto_smooth = True
         layout.operator("object.shade_flat")
 
         layout.separator()
@@ -2588,7 +2589,8 @@ class VIEW3D_MT_object_context_menu(Menu):
         # Shared among some object types.
         if obj is not None:
             if obj.type in {'MESH', 'CURVE', 'SURFACE'}:
-                layout.operator("object.shade_smooth", text="Shade Smooth")
+                layout.operator("object.shade_smooth")
+                layout.operator("object.shade_smooth", text="Shade Auto Smooth").use_auto_smooth = True
                 layout.operator("object.shade_flat", text="Shade Flat")
 
                 layout.separator()

source/blender/blenkernel/BKE_mesh.h

@@ -204,6 +204,7 @@ bool BKE_mesh_material_index_used(struct Mesh *me, short index);
 void BKE_mesh_material_index_clear(struct Mesh *me);
 void BKE_mesh_material_remap(struct Mesh *me, const unsigned int *remap, unsigned int remap_len);
 void BKE_mesh_smooth_flag_set(struct Mesh *me, bool use_smooth);
+void BKE_mesh_auto_smooth_flag_set(struct Mesh *me, bool use_auto_smooth, float auto_smooth_angle);
 
 /**
  * Needed after converting a mesh with subsurf optimal display to mesh.

source/blender/blenkernel/intern/mesh.cc

@@ -1577,6 +1577,19 @@ void BKE_mesh_smooth_flag_set(Mesh *me, const bool use_smooth)
   }
 }
 
+void BKE_mesh_auto_smooth_flag_set(Mesh *me,
+                                   const bool use_auto_smooth,
+                                   const float auto_smooth_angle)
+{
+  if (use_auto_smooth) {
+    me->flag |= ME_AUTOSMOOTH;
+    me->smoothresh = auto_smooth_angle;
+  }
+  else {
+    me->flag &= ~ME_AUTOSMOOTH;
+  }
+}
+
 int poly_find_loop_from_vert(const MPoly *poly, const MLoop *loopstart, uint vert)
 {
   for (int j = 0; j < poly->totloop; j++, loopstart++) {

source/blender/editors/object/object_edit.c

@@ -17,6 +17,7 @@
 
 #include "BLI_blenlib.h"
 #include "BLI_ghash.h"
+#include "BLI_math_rotation.h"
 #include "BLI_utildefines.h"
 
 #include "BLT_translation.h"
@@ -86,6 +87,7 @@
 #include "RNA_access.h"
 #include "RNA_define.h"
 #include "RNA_enum_types.h"
+#include "RNA_types.h"
 
 #include "UI_interface_icons.h"
 
@@ -1461,6 +1463,8 @@ void OBJECT_OT_paths_clear(wmOperatorType *ot)
 static int shade_smooth_exec(bContext *C, wmOperator *op)
 {
   const bool use_smooth = STREQ(op->idname, "OBJECT_OT_shade_smooth");
+  const bool use_auto_smooth = RNA_boolean_get(op->ptr, "use_auto_smooth");
+  const float auto_smooth_angle = RNA_float_get(op->ptr, "auto_smooth_angle");
   bool changed_multi = false;
   bool has_linked_data = false;
 
@@ -1508,6 +1512,7 @@ static int shade_smooth_exec(bContext *C, wmOperator *op)
     bool changed = false;
     if (ob->type == OB_MESH) {
       BKE_mesh_smooth_flag_set(ob->data, use_smooth);
+      BKE_mesh_auto_smooth_flag_set(ob->data, use_auto_smooth, auto_smooth_angle);
       BKE_mesh_batch_cache_dirty_tag(ob->data, BKE_MESH_BATCH_DIRTY_ALL);
       changed = true;
     }
@@ -1577,6 +1582,25 @@ void OBJECT_OT_shade_smooth(wmOperatorType *ot)
 
   /* flags */
   ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
+
+  /* properties */
+  PropertyRNA *prop;
+
+  prop = RNA_def_boolean(
+      ot->srna,
+      "use_auto_smooth",
+      false,
+      "Auto Smooth",
+      "Enable automatic smooth based on smooth/sharp faces/edges and angle between faces");
+  RNA_def_property_flag(prop, PROP_SKIP_SAVE);
+
+  prop = RNA_def_property(ot->srna, "auto_smooth_angle", PROP_FLOAT, PROP_ANGLE);
+  RNA_def_property_range(prop, 0.0f, DEG2RADF(180.0f));
+  RNA_def_property_float_default(prop, DEG2RADF(30.0f));
+  RNA_def_property_ui_text(prop,
+                           "Angle",
+                           "Maximum angle between face normals that will be considered as smooth"
+                           "(unused if custom split normals data are available)");
 }
 
 /** \} */