Sculpt: Cloth Brush/Filter Collisions

This implements collisions in the solver of the cloth brush/filter. It
uses the scene colliders as a regular physics simulation.

There are still some parameters (friction, distance to the surface...)
that can be exposed as properties in later patches.

Thanks to Sebastian Parborg for helping me with the implementation.

Reviewed By: sergey, zeddb

Differential Revision: https://developer.blender.org/D8019

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_paint.h b/source/blender/blenkernel/BKE_paint.h
index e2b8a4d72e6..d5b09cff293 100644
--- a/source/blender/blenkernel/BKE_paint.h
+++ b/source/blender/blenkernel/BKE_paint.h
@@ -42,6 +42,7 @@ struct EdgeSet;
 struct GHash;
 struct GridPaintMask;
 struct ImagePool;
+struct ListBase;
 struct MLoop;
 struct MLoopTri;
 struct MVert;
@@ -295,7 +296,9 @@ typedef struct SculptClothSimulation {
   float (*pos)[3];
   float (*init_pos)[3];
   float (*prev_pos)[3];
+  float (*last_iteration_pos)[3];
 
+  struct ListBase *collider_list;
 } SculptClothSimulation;
 
 typedef struct SculptPersistentBase {
@@ -333,6 +336,9 @@ typedef struct SculptSession {
     int level;
   } multires;
 
+  /* Depsgraph for the Cloth Brush solver to get the colliders. */
+  struct Depsgraph *depsgraph;
+
   /* These are always assigned to base mesh data when using PBVH_FACES and PBVH_GRIDS. */
   struct MVert *mvert;
   struct MPoly *mpoly;