Partial response force for hair collisions.

This implements a penalty force as well as a repulsion force to avoid
further penetration, as suggested in
"Simulating Complex Hair with Robust Collision Handling"
(http://graphics.snu.ac.kr/publications/2005-choe-HairSim/Choe_2005_SCA.pdf)

Friction forces are still missing. More problematic is handling of
moving colliders, when face swap places with the hair vertex and a
collision is missed, putting the vertex inside the mesh volume. Larger
margins might help, but ultimately using Bullet collision detection is
probably more reliable and failsafe.

1 files changed, 3 insertions, 2 deletions

diff --git a/source/blender/makesdna/DNA_cloth_types.h b/source/blender/makesdna/DNA_cloth_types.h
index a9e066ef45e..4d862e48109 100644
--- a/source/blender/makesdna/DNA_cloth_types.h
+++ b/source/blender/makesdna/DNA_cloth_types.h
@@ -99,15 +99,16 @@ typedef struct ClothCollSettings {
 	float	epsilon;		/* min distance for collisions.		*/
 	float	self_friction;		/* Fiction/damping with self contact. */
 	float	friction;		/* Friction/damping applied on contact with other object.*/
+	float	damping;	/* Collision restitution on contact with other object.*/
 	float 	selfepsilon; 		/* for selfcollision */
 	float repel_force, distance_repel;
 	int	flags;			/* collision flags defined in BKE_cloth.h */
 	short	self_loop_count;	/* How many iterations for the selfcollision loop	*/
 	short	loop_count;		/* How many iterations for the collision loop.		*/
+	int pad;
 	struct Group *group;	/* Only use colliders from this group of objects */
 	short	vgroup_selfcol; /* vgroup to paint which vertices are used for self collisions */
-	short pad;
-	int pad2;
+	short pad2[3];
 } ClothCollSettings;