Sculpt: Boundary Brush

This brush includes a set of deformation modes designed to deform and
control the shape of the mesh boundaries, which are really hard to do
with regular sculpt brushes (and even in edit mode). This is useful
for creating cloth assets and hard surface base meshes.

The brush detects the mesh boundary closest to the active vertex and
propagates the deformation using the brush falloff into the mesh.
It includes bend, expand, inflate, grab and twist deform modes.

The main use cases of this brush are the Bend and Expand deformation
modes, which depend on a grid topology to create the best results.
In order to do further adjustments and tweaks to the result of these
deformation modes, the brush also includes the Inflate, Grab and
Twist deformation modes, which do not depend that much on the topology.

Grab and Inflate are the same operation that is implemented in the
Grab and Inflate tools, they are also available in the boundary brush
as producing deformations with regular brushes in these areas is very
hard to control.

Even if this brush can produce deformations in triangle meshes and
meshes with a non-regular quad grid, the more regular and clean the
topology is, the better. Most of the assets this brush is intended to
deform are always created from a cylindrical or plane quad grid, so it
should be fine. Also, its algorithms can be improved in future versions
to handle more corner cases and topology patterns.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D8356

1 files changed, 13 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_brush_types.h b/source/blender/makesdna/DNA_brush_types.h
index 036c6c9c9d6..503dba776a7 100644
--- a/source/blender/makesdna/DNA_brush_types.h
+++ b/source/blender/makesdna/DNA_brush_types.h
@@ -379,6 +379,14 @@ typedef enum eBrushSlideDeformType {
   BRUSH_SLIDE_DEFORM_EXPAND = 2,
 } eBrushSlideDeformType;
 
+typedef enum eBrushBoundaryDeformType {
+  BRUSH_BOUNDARY_DEFORM_BEND = 0,
+  BRUSH_BOUNDARY_DEFORM_EXPAND = 1,
+  BRUSH_BOUNDARY_DEFORM_INFLATE = 2,
+  BRUSH_BOUNDARY_DEFORM_GRAB = 3,
+  BRUSH_BOUNDARY_DEFORM_TWIST = 4,
+} eBrushBushBoundaryDeformType;
+
 /* Gpencilsettings.Vertex_mode */
 typedef enum eGp_Vertex_Mode {
   /* Affect to Stroke only. */
@@ -524,7 +532,7 @@ typedef struct Brush {
   /** Source for fill tool color gradient application. */
   char gradient_fill_mode;
 
-  char _pad0[5];
+  char _pad0[1];
 
   /** Projection shape (sphere, circle). */
   char falloff_shape;
@@ -586,6 +594,9 @@ typedef struct Brush {
   int pose_ik_segments;
   int pose_origin_type;
 
+  /* boundary */
+  int boundary_deform_type;
+
   /* cloth */
   int cloth_deform_type;
   int cloth_force_falloff_type;
@@ -798,6 +809,7 @@ typedef enum eBrushSculptTool {
   SCULPT_TOOL_DRAW_FACE_SETS = 27,
   SCULPT_TOOL_PAINT = 28,
   SCULPT_TOOL_SMEAR = 29,
+  SCULPT_TOOL_BOUNDARY = 30,
 } eBrushSculptTool;
 
 /* Brush.uv_sculpt_tool */