Sculpt: Surface Smooth Brush and Mesh Filter

This implements the Surface Smooth Brush as a mode inside the Smooth tool,
which uses the HC algorithm from "Improved Laplacian Smoothing of Noisy Surface Meshes".
Comparted to the regular smooth brush with laplacian smooth, this brush removes
the surface while preserving the volume of the object.
The smooth result can be controlled by tweaing the original shape preservation,
displacement and iteration count.
The same surface smooth operation is also available as a mesh filter.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D7057

1 files changed, 11 insertions, 0 deletions

diff --git a/source/blender/makesdna/DNA_brush_types.h b/source/blender/makesdna/DNA_brush_types.h
index 1fad828e887..59e9d3be58d 100644
--- a/source/blender/makesdna/DNA_brush_types.h
+++ b/source/blender/makesdna/DNA_brush_types.h
@@ -281,6 +281,11 @@ typedef enum eBrushClothDeformType {
   BRUSH_CLOTH_DEFORM_EXPAND = 6,
 } eBrushClothDeformType;
 
+typedef enum eBrushSmoothDeformType {
+  BRUSH_SMOOTH_DEFORM_LAPLACIAN = 0,
+  BRUSH_SMOOTH_DEFORM_SURFACE = 1,
+} eBrushSmoothDeformType;
+
 typedef enum eBrushClothForceFalloffType {
   BRUSH_CLOTH_FORCE_FALLOFF_RADIAL = 0,
   BRUSH_CLOTH_FORCE_FALLOFF_PLANE = 1,
@@ -473,6 +478,12 @@ typedef struct Brush {
   float cloth_sim_limit;
   float cloth_sim_falloff;
 
+  /* smooth */
+  int smooth_deform_type;
+  float surface_smooth_shape_preservation;
+  float surface_smooth_current_vertex;
+  int surface_smooth_iterations;
+
   /* multiplane scrape */
   float multiplane_scrape_angle;