Sculpt: Cloth brush

This brush has a simple physics solver that helps when sculpting cloth.

- The mass and the damping properties of the simulation are properties of the brush.
- It has two additional radius control to limit the influence and falloff of the simulation.
- Masked vertices are pinned in the simulation, and it applies the sculpt gravity directly in the solver.
- The Cloth Brush has 7 deformation modes with 2 falloff types (radial and plane).

The brush can create the constraints only on the required PBVH nodes, so the simulation is isolated on high poly meshes. As long
as the brush size is not too big it should be possible to keep it real time.

Known issues:
- The way constraints are created is extremely basic and it creates repeated constraints. Maybe there is another way to create fewer constraints while keeping the simulation quality decent. This part can also be multithreaded. (As it is it works ok, but it could be better)

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D6715

1 files changed, 63 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_brush.c b/source/blender/makesrna/intern/rna_brush.c
index a219bbcfc8e..5f30e299a12 100644
--- a/source/blender/makesrna/intern/rna_brush.c
+++ b/source/blender/makesrna/intern/rna_brush.c
@@ -96,6 +96,7 @@ const EnumPropertyItem rna_enum_brush_sculpt_tool_items[] = {
     {SCULPT_TOOL_ROTATE, "ROTATE", ICON_BRUSH_ROTATE, "Rotate", ""},
     {SCULPT_TOOL_SLIDE_RELAX, "TOPOLOGY", ICON_BRUSH_GRAB, "Slide Relax", ""},
     {0, "", 0, NULL, NULL},
+    {SCULPT_TOOL_CLOTH, "CLOTH", ICON_BRUSH_SCULPT_DRAW, "Cloth", ""},
     {SCULPT_TOOL_SIMPLIFY, "SIMPLIFY", ICON_BRUSH_DATA, "Simplify", ""},
     {SCULPT_TOOL_MASK, "MASK", ICON_BRUSH_MASK, "Mask", ""},
     {0, NULL, 0, NULL, NULL},
@@ -1641,6 +1642,27 @@ static void rna_def_brush(BlenderRNA *brna)
       {0, NULL, 0, NULL, NULL},
   };
 
+  static const EnumPropertyItem brush_cloth_deform_type_items[] = {
+      {BRUSH_CLOTH_DEFORM_DRAG, "DRAG", 0, "Drag", ""},
+      {BRUSH_CLOTH_DEFORM_PUSH, "PUSH", 0, "Push", ""},
+      {BRUSH_CLOTH_DEFORM_PINCH_POINT, "PINCH_POINT", 0, "Pinch Point", ""},
+      {BRUSH_CLOTH_DEFORM_PINCH_PERPENDICULAR,
+       "PINCH_PERPENDICULAR",
+       0,
+       "Pinch Perpendicular",
+       ""},
+      {BRUSH_CLOTH_DEFORM_INFLATE, "INFLATE", 0, "Inflate", ""},
+      {BRUSH_CLOTH_DEFORM_GRAB, "GRAB", 0, "Grab", ""},
+      {BRUSH_CLOTH_DEFORM_EXPAND, "EXPAND", 0, "Expand", ""},
+      {0, NULL, 0, NULL, NULL},
+  };
+
+  static const EnumPropertyItem brush_cloth_force_falloff_type_items[] = {
+      {BRUSH_CLOTH_FORCE_FALLOFF_RADIAL, "RADIAL", 0, "Radial", ""},
+      {BRUSH_CLOTH_FORCE_FALLOFF_PLANE, "PLANE", 0, "Plane", ""},
+      {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");
@@ -1726,6 +1748,17 @@ static void rna_def_brush(BlenderRNA *brna)
   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, "cloth_deform_type", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, brush_cloth_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, "cloth_force_falloff_type", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_items(prop, brush_cloth_force_falloff_type_items);
+  RNA_def_property_ui_text(
+      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, "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);
@@ -1949,6 +1982,36 @@ static void rna_def_brush(BlenderRNA *brna)
   RNA_def_property_ui_text(prop, "Tip Roundness", "Roundness of the brush tip");
   RNA_def_property_update(prop, 0, "rna_Brush_update");
 
+  prop = RNA_def_property(srna, "cloth_mass", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_float_sdna(prop, NULL, "cloth_mass");
+  RNA_def_property_range(prop, 0.01f, 2.0f);
+  RNA_def_property_ui_text(prop, "Cloth mass", "Mass of each simulation particle");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
+  prop = RNA_def_property(srna, "cloth_damping", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_float_sdna(prop, NULL, "cloth_damping");
+  RNA_def_property_range(prop, 0.01f, 1.0f);
+  RNA_def_property_ui_text(
+      prop, "Cloth Damping", "How much the applied forces are propagated through the cloth");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
+  prop = RNA_def_property(srna, "cloth_sim_limit", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_float_sdna(prop, NULL, "cloth_sim_limit");
+  RNA_def_property_range(prop, 0.1f, 10.0f);
+  RNA_def_property_ui_text(
+      prop,
+      "Simulation Limit",
+      "Factor added relative to the size of the radius to limit the cloth simulation effects");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
+  prop = RNA_def_property(srna, "cloth_sim_falloff", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_float_sdna(prop, NULL, "cloth_sim_falloff");
+  RNA_def_property_range(prop, 0.0f, 1.0f);
+  RNA_def_property_ui_text(prop,
+                           "Simulation Falloff",
+                           "Area to apply deformation falloff to the effects of the simulation");
+  RNA_def_property_update(prop, 0, "rna_Brush_update");
+
   prop = RNA_def_property(srna, "auto_smooth_factor", PROP_FLOAT, PROP_FACTOR);
   RNA_def_property_float_sdna(prop, NULL, "autosmooth_factor");
   RNA_def_property_float_default(prop, 0);