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, 42 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_brush.c b/source/blender/makesrna/intern/rna_brush.c
index a4091718487..1a163c9e2eb 100644
--- a/source/blender/makesrna/intern/rna_brush.c
+++ b/source/blender/makesrna/intern/rna_brush.c
@@ -1794,6 +1794,20 @@ static void rna_def_brush(BlenderRNA *brna)
       {0, NULL, 0, NULL, NULL},
   };
 
+  static const EnumPropertyItem brush_smooth_deform_type_items[] = {
+      {BRUSH_SMOOTH_DEFORM_LAPLACIAN,
+       "LAPLACIAN",
+       0,
+       "Laplacian",
+       "Smooths the surface and the volume"},
+      {BRUSH_SMOOTH_DEFORM_SURFACE,
+       "SURFACE",
+       0,
+       "Surface",
+       "Smooths the surface of the mesh, preserving the volue"},
+      {0, NULL, 0, NULL, NULL},
+  };
+
   srna = RNA_def_struct(brna, "Brush", "ID");
   RNA_def_struct_ui_text(
       srna, "Brush", "Brush data-block for storing brush settings for painting and sculpting");
@@ -1909,6 +1923,11 @@ static void rna_def_brush(BlenderRNA *brna)
       prop, "Force Falloff", "Shape used in the brush to apply force to the cloth");
   RNA_def_property_update(prop, 0, "rna_Brush_update");
 
+  prop = RNA_def_property(srna, "smooth_deform_type", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, brush_smooth_deform_type_items);
+  RNA_def_property_ui_text(prop, "Deformation", "Deformation type that is used in the brush");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
   prop = RNA_def_property(srna, "jitter_unit", PROP_ENUM, PROP_NONE); /* as an enum */
   RNA_def_property_enum_bitflag_sdna(prop, NULL, "flag");
   RNA_def_property_enum_items(prop, brush_jitter_unit_items);
@@ -2101,6 +2120,29 @@ static void rna_def_brush(BlenderRNA *brna)
       prop, "Pose Origin Offset", "Offset of the pose origin in relation to the brush radius");
   RNA_def_property_update(prop, 0, "rna_Brush_update");
 
+  prop = RNA_def_property(srna, "surface_smooth_shape_preservation", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_float_sdna(prop, NULL, "surface_smooth_shape_preservation");
+  RNA_def_property_range(prop, 0.0f, 1.0f);
+  RNA_def_property_ui_text(
+      prop, "Shape Preservation", "How much of the original shape is preserved when smoothing");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
+  prop = RNA_def_property(srna, "surface_smooth_current_vertex", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_float_sdna(prop, NULL, "surface_smooth_current_vertex");
+  RNA_def_property_range(prop, 0.0f, 1.0f);
+  RNA_def_property_ui_text(
+      prop,
+      "Per Vertex Displacement",
+      "How much the position of each individual vertex influences the final result");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
+  prop = RNA_def_property(srna, "surface_smooth_iterations", PROP_INT, PROP_UNSIGNED);
+  RNA_def_property_int_sdna(prop, NULL, "surface_smooth_iterations");
+  RNA_def_property_range(prop, 1, 10);
+  RNA_def_property_ui_range(prop, 1, 10, 1, 3);
+  RNA_def_property_ui_text(prop, "Iterations", "Number of smoothing iterations per brush step");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
   prop = RNA_def_property(srna, "multiplane_scrape_angle", PROP_FLOAT, PROP_FACTOR);
   RNA_def_property_float_sdna(prop, NULL, "multiplane_scrape_angle");
   RNA_def_property_range(prop, 0.0f, 160.0f);