Cloth: Fixed: [#8210] (includes bad spring calculation), only mesh can get cloth assigned, New: initial try of Bridson/Fedkiw friction formula implementation, better GUI feedback when e.g. cache is protected and settings too

6 files changed, 224 insertions, 197 deletions

diff --git a/source/blender/blenkernel/intern/cloth.c b/source/blender/blenkernel/intern/cloth.c
index ace5f37b7a4..e27df5b1ba1 100644
--- a/source/blender/blenkernel/intern/cloth.c
+++ b/source/blender/blenkernel/intern/cloth.c
@@ -166,7 +166,7 @@ void cloth_init ( ClothModifierData *clmd )
 	clmd->sim_parms->firstcachedframe = -1.0;
 	
 	clmd->coll_parms->self_friction = 5.0;
-	clmd->coll_parms->friction = 10.0;
+	clmd->coll_parms->friction = 5.0;
 	clmd->coll_parms->loop_count = 3;
 	clmd->coll_parms->epsilon = 0.015f;
 	clmd->coll_parms->flags = CLOTH_COLLSETTINGS_FLAG_ENABLED;
@@ -689,7 +689,7 @@ DerivedMesh *clothModifier_do(ClothModifierData *clmd,Object *ob, DerivedMesh *d
 	clmd->sim_parms->dt = 1.0f / clmd->sim_parms->stepsPerFrame;
 	
 	if ( ( clmd->clothObject == NULL ) || (clmd->clothObject && (numverts != clmd->clothObject->numverts )) )
-	{
+	{	
 		/* only force free the cache if we have a different number of verts */
 		if(clmd->clothObject && (numverts != clmd->clothObject->numverts ))
 		{
@@ -756,6 +756,16 @@ DerivedMesh *clothModifier_do(ClothModifierData *clmd,Object *ob, DerivedMesh *d
 		return result;
 	}
 	
+	// check for autoprotection
+	if(framenr >= clmd->sim_parms->autoprotect)
+	{
+		if(G.rt > 0)
+			printf("fr#: %f, auto: %d\n", framenr, clmd->sim_parms->autoprotect);
+		clmd->sim_parms->flags |= CLOTH_SIMSETTINGS_FLAG_CCACHE_PROTECT;
+	}
+	if(G.rt > 0)
+		printf("clothModifier_do deltaTime=1 cachewrite\n");
+	
 	/* nice moving one frame forward */
 	if ( deltaTime == 1.0f )
 	{
@@ -795,16 +805,6 @@ DerivedMesh *clothModifier_do(ClothModifierData *clmd,Object *ob, DerivedMesh *d
 				cloth_write_cache(ob, clmd, framenr);
 			else
 				clmd->sim_parms->sim_time--;
-			
-			// check for autoprotection
-			if(framenr >= clmd->sim_parms->autoprotect)
-			{
-				if(G.rt > 0)
-					printf("fr#: %f, auto: %d\n", framenr, clmd->sim_parms->autoprotect);
-				clmd->sim_parms->flags |= CLOTH_SIMSETTINGS_FLAG_CCACHE_PROTECT;
-			}
-			if(G.rt > 0)
-				printf("clothModifier_do deltaTime=1 cachewrite\n");
 		}
 		else
 		{
@@ -1041,14 +1041,16 @@ static void cloth_apply_vgroup ( ClothModifierData *clmd, DerivedMesh *dm )
 
 	verts = clothObj->verts;
 	
-	if (((clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_SCALING ) || 
+	if ((((clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_SCALING ) || 
 		     (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL )) && 
 		     ((clmd->sim_parms->vgroup_mass>0) || 
 		     (clmd->sim_parms->vgroup_struct>0)||
-		     (clmd->sim_parms->vgroup_bend>0)))
+		     (clmd->sim_parms->vgroup_bend>0)))|| (clmd->sim_parms->vgroup_mass>0))
 	{
 		for ( i = 0; i < numverts; i++, verts++ )
 		{
+			verts->mass = 1.0; // standard mass
+			
 			dvert = dm->getVertData ( dm, i, CD_MDEFORMVERT );
 			if ( dvert )
 			{
@@ -1082,26 +1084,17 @@ static void cloth_apply_vgroup ( ClothModifierData *clmd, DerivedMesh *dm )
 							verts->bend_stiff = dvert->dw [j].weight;
 						}
 					}
+					
+					if( dvert->dw[j].def_nr == (clmd->sim_parms->vgroup_mass-1))
+					{
+						verts->mass = dvert->dw [j].weight;
+					}
 				}
 			}
 		}
 	}
 }
 
-/*
-helper function to get proper spring length
-when object is rescaled
-*/
-float cloth_globallen ( float *v1,float *v2,Object *ob )
-{
-	float p1[3],p2[3];
-	VECCOPY ( p1,v1 );
-	Mat4MulVecfl ( ob->obmat, p1 );
-	VECCOPY ( p2,v2 );
-	Mat4MulVecfl ( ob->obmat, p2 );
-	return VecLenf ( p1,p2 );
-}
-
 static int cloth_from_object(Object *ob, ClothModifierData *clmd, DerivedMesh *dm, float framenr)
 {
 	unsigned int i = 0;
@@ -1189,6 +1182,7 @@ static int cloth_from_object(Object *ob, ClothModifierData *clmd, DerivedMesh *d
 	// has to be happen before springs are build!
 	cloth_apply_vgroup (clmd, dm);
 	
+	
 	if ( !cloth_build_springs ( clmd, dm ) )
 	{
 		cloth_free_modifier ( ob, clmd );
@@ -1197,12 +1191,13 @@ static int cloth_from_object(Object *ob, ClothModifierData *clmd, DerivedMesh *d
 		return 0;
 	}
 	
+	
 	// init our solver
 	if ( solvers [clmd->sim_parms->solver_type].init )
 		solvers [clmd->sim_parms->solver_type].init ( ob, clmd );
 
 	clmd->clothObject->tree = bvh_build_from_cloth ( clmd, clmd->coll_parms->epsilon );
-	
+
 	return 1;
 }
 
@@ -1326,14 +1321,6 @@ int cloth_build_springs ( ClothModifierData *clmd, DerivedMesh *dm )
 			spring->kl = medge[i].v2;
 			VECSUB ( temp, cloth->verts[spring->kl].x, cloth->verts[spring->ij].x );
 			spring->restlen =  sqrt ( INPR ( temp, temp ) );
-			/*
-			if(spring->restlen > 1.0)
-			{
-			printf("i: %d, L: %f\n", i, spring->restlen);
-			printf("%d, x: %f, y: %f, z: %f\n", cloth->verts[spring->ij].x[0], cloth->verts[spring->ij].x[1], spring->ij, cloth->verts[spring->ij].x[2]);
-			printf("%d, x: %f, y: %f, z: %f\n\n",spring->kl, cloth->verts[spring->kl].x[0], cloth->verts[spring->kl].x[1], cloth->verts[spring->kl].x[2]);
-		}
-			*/
 			clmd->coll_parms->avg_spring_len += spring->restlen;
 			spring->type = CLOTH_SPRING_TYPE_STRUCTURAL;
 			spring->flags = 0;
@@ -1438,6 +1425,9 @@ int cloth_build_springs ( ClothModifierData *clmd, DerivedMesh *dm )
 		MEM_freeN ( edgelist );
 	
 	BLI_edgehash_free ( edgehash, NULL );
+	
+	if(G.rt>0)
+		printf("avg_len: %f\n",clmd->coll_parms->avg_spring_len);
 
 	return 1;
 
diff --git a/source/blender/blenkernel/intern/collision.c b/source/blender/blenkernel/intern/collision.c
index afca64670eb..7304ae09ef8 100644
--- a/source/blender/blenkernel/intern/collision.c
+++ b/source/blender/blenkernel/intern/collision.c
@@ -437,17 +437,6 @@ DO_INLINE void interpolateOnTriangle(float to[3], float v1[3], float v2[3], floa
 	VECADDMUL(to, v3, w3);
 }
 
-// unused in the moment, has some bug in
-DO_INLINE void calculateFrictionImpulse(float to[3], float vrel[3], float normal[3], double normalVelocity,
-					double frictionConstant, double delta_V_n) 
-{
-	float vrel_t_pre[3];
-	float vrel_t[3];
-	VECSUBS(vrel_t_pre, vrel, normal, normalVelocity);
-	VECCOPY(to, vrel_t_pre);
-	VecMulf(to, MAX2(1.0f - frictionConstant * delta_V_n / INPR(vrel_t_pre,vrel_t_pre), 0.0f));
-}
-
 int cloth_collision_response_static(ClothModifierData *clmd, CollisionModifierData *collmd)
 {
 	unsigned int i = 0;
@@ -477,9 +466,9 @@ int cloth_collision_response_static(ClothModifierData *clmd, CollisionModifierDa
 		// was: txold
 		cloth_compute_barycentric(collpair->pb,
 					  collmd->current_x[collpair->bp1].co,
-       collmd->current_x[collpair->bp2].co,
-       collmd->current_x[collpair->bp3].co,
-       &u1, &u2, &u3);
+					collmd->current_x[collpair->bp2].co,
+					collmd->current_x[collpair->bp3].co,
+					&u1, &u2, &u3);
 	
 		// Calculate relative "velocity".
 		interpolateOnTriangle(v1, cloth1->verts[collpair->ap1].tv, cloth1->verts[collpair->ap2].tv, cloth1->verts[collpair->ap3].tv, w1, w2, w3);
@@ -494,43 +483,45 @@ int cloth_collision_response_static(ClothModifierData *clmd, CollisionModifierDa
 		// printf("magrelVel: %f\n", magrelVel);
 				
 		// Calculate masses of points.
+		// TODO
 		
 		// If v_n_mag < 0 the edges are approaching each other.
 		if(magrelVel < -ALMOST_ZERO) 
 		{
 			// Calculate Impulse magnitude to stop all motion in normal direction.
-			// const double I_mag = v_n_mag / (1/m1 + 1/m2);
-			float magnitude_i = magrelVel / 2.0f; // TODO implement masses
-			float tangential[3], magtangent, magnormal, collvel[3];
-			float vrel_t_pre[3];
-			float vrel_t[3];
-			double impulse;
+			float magnitude_i = magrelVel / 2.0; // TODO implement masses
+			float tangential[3], magtangent, magnormal;
+			double impulse = 0.0;
 			float epsilon = clmd->coll_parms->epsilon;
-			float overlap = (epsilon + ALMOST_ZERO-collpair->distance);
+			float vrel_t_pre[3];
+			float vrel_t[3], temp[3];
+			
+			VECCOPY(temp, collpair->normal);
+			VecMulf(temp, magrelVel);
+			VECSUB(vrel_t_pre, relativeVelocity, temp);
+			
+			VECCOPY(vrel_t, vrel_t_pre);
+			
+			VecMulf(vrel_t, MAX2(1.0 - (clmd->coll_parms->friction * magrelVel / sqrt(INPR(vrel_t_pre,vrel_t_pre))), 0));
 			
-			// calculateFrictionImpulse(tangential, relativeVelocity, collpair->normal, magrelVel, clmd->coll_parms->friction*0.01, magrelVel);
+			VECSUB(tangential, vrel_t_pre, vrel_t);
+			VecMulf(tangential, 0.5);
 			
-			// magtangent = INPR(tangential, tangential);
+			// i_tangential = tangential
+			magtangent = INPR(tangential, tangential);
 			
 			// Apply friction impulse.
-			if (magtangent < -ALMOST_ZERO) 
+			if (magtangent > ALMOST_ZERO) 
 			{
-				
-				// printf("friction applied: %f\n", magtangent);
-				// TODO check original code 
-				/*
-				VECSUB(cloth1->verts[face1->v1].tv, cloth1->verts[face1->v1].tv,tangential);
-				VECSUB(cloth1->verts[face1->v1].tv, cloth1->verts[face1->v2].tv,tangential);
-				VECSUB(cloth1->verts[face1->v1].tv, cloth1->verts[face1->v3].tv,tangential);
-				VECSUB(cloth1->verts[face1->v1].tv, cloth1->verts[face1->v4].tv,tangential);
-				*/
+				impulse = magtangent / ( 1.0 + w1*w1 + w2*w2 + w3*w3);
+				VECADDMUL(cloth1->verts[collpair->ap1].impulse, tangential, w1 * impulse/magtangent);
+				VECADDMUL(cloth1->verts[collpair->ap2].impulse, tangential, w2 * impulse/magtangent);
+				VECADDMUL(cloth1->verts[collpair->ap3].impulse, tangential, w3 * impulse/magtangent);
 			}
 			
 
 			impulse = -2.0f * magrelVel / ( 1.0 + w1*w1 + w2*w2 + w3*w3);
 			
-			// printf("impulse: %f\n", impulse);
-			
 			VECADDMUL(cloth1->verts[collpair->ap1].impulse, collpair->normal, w1 * impulse); 
 			cloth1->verts[collpair->ap1].impulse_count++;
 			
@@ -541,40 +532,6 @@ int cloth_collision_response_static(ClothModifierData *clmd, CollisionModifierDa
 			cloth1->verts[collpair->ap3].impulse_count++;
 			
 			result = 1;
-			
-			/*
-			if (overlap > ALMOST_ZERO) {
-			double I_mag  = overlap * 0.1;
-				
-			impulse = -I_mag / ( 1.0 + w1*w1 + w2*w2 + w3*w3);
-				
-			VECADDMUL(cloth1->verts[collpair->ap1].impulse, collpair->normal, w1 * impulse); 
-			cloth1->verts[collpair->ap1].impulse_count++;
-							
-			VECADDMUL(cloth1->verts[collpair->ap2].impulse, collpair->normal, w2 * impulse); 
-			cloth1->verts[collpair->ap2].impulse_count++;
-			
-			VECADDMUL(cloth1->verts[collpair->ap3].impulse, collpair->normal, w3 * impulse); 
-			cloth1->verts[collpair->ap3].impulse_count++;
-		}
-			*/
-		
-			// printf("magnitude_i: %f\n", magnitude_i); // negative before collision in my case
-			
-			// Apply the impulse and increase impulse counters.
-
-			/*		
-			// calculateFrictionImpulse(tangential, collvel, collpair->normal, magtangent, clmd->coll_parms->friction*0.01, magtangent);
-			VECSUBS(vrel_t_pre, collvel, collpair->normal, magnormal);
-			// VecMulf(vrel_t_pre, clmd->coll_parms->friction*0.01f/INPR(vrel_t_pre,vrel_t_pre));
-			magtangent = Normalize(vrel_t_pre);
-			VecMulf(vrel_t_pre, MIN2(clmd->coll_parms->friction*0.01f*magnormal,magtangent));
-			
-			VECSUB(cloth1->verts[face1->v1].tv, cloth1->verts[face1->v1].tv,vrel_t_pre);
-			*/
-			
-			
-			
 		}
 		
 		search = search->next;
diff --git a/source/blender/blenkernel/intern/implicit.c b/source/blender/blenkernel/intern/implicit.c
index d08997d87eb..8490966283e 100644
--- a/source/blender/blenkernel/intern/implicit.c
+++ b/source/blender/blenkernel/intern/implicit.c
@@ -114,6 +114,9 @@ double itval()
 /* callbacks for errors and interrupts and some goo */
 static int (*CT_localInterruptCallBack)(void) = NULL;
 
+static float I[3][3] = {{1,0,0},{0,1,0},{0,0,1}};
+static float ZERO[3][3] = {{0,0,0}, {0,0,0}, {0,0,0}};
+
 /*
 #define C99
 #ifdef C99
@@ -131,7 +134,7 @@ struct Cloth;
 /* DEFINITIONS */
 typedef float lfVector[3];
 typedef struct fmatrix3x3 {
-	float m[3][3]; /* 4x4 matrix */
+	float m[3][3]; /* 3x3 matrix */
 	unsigned int c,r; /* column and row number */
 	int pinned; /* is this vertex allowed to move? */
 	float n1,n2,n3; /* three normal vectors for collision constrains */
@@ -170,11 +173,13 @@ DO_INLINE void mul_fvectorT_fvector(float to[3][3], float vectorA[3], float vect
 /* STATUS: HAS TO BE verified (*should* work) */
 DO_INLINE void mul_fvectorT_fvectorS(float to[3][3], float vectorA[3], float vectorB[3], float aS)
 {
-	mul_fvector_S(to[0], vectorB, vectorA[0]* aS);
-	mul_fvector_S(to[1], vectorB, vectorA[1]* aS);
-	mul_fvector_S(to[2], vectorB, vectorA[2]* aS);
+	mul_fvectorT_fvector(to, vectorA, vectorB);
+	mul_fvector_S(to[0], to[0], aS);
+	mul_fvector_S(to[1], to[1], aS);
+	mul_fvector_S(to[2], to[2], aS);
 }
 
+
 /* printf vector[3] on console: for debug output */
 void print_fvector(float m3[3])
 {
@@ -315,16 +320,17 @@ DO_INLINE void sub_lfvector_lfvector(float (*to)[3], float (*fLongVectorA)[3], f
 
 }
 ///////////////////////////
-// 4x4 matrix
+// 3x3 matrix
 ///////////////////////////
-/* printf 4x4 matrix on console: for debug output */
+/* printf 3x3 matrix on console: for debug output */
 void print_fmatrix(float m3[3][3])
 {
 	printf("%f\t%f\t%f\n",m3[0][0],m3[0][1],m3[0][2]);
 	printf("%f\t%f\t%f\n",m3[1][0],m3[1][1],m3[1][2]);
 	printf("%f\t%f\t%f\n\n",m3[2][0],m3[2][1],m3[2][2]);
 }
-/* copy 4x4 matrix */
+
+/* copy 3x3 matrix */
 DO_INLINE void cp_fmatrix(float to[3][3], float from[3][3])
 {
 	// memcpy(to, from, sizeof (float) * 9);
@@ -332,12 +338,24 @@ DO_INLINE void cp_fmatrix(float to[3][3], float from[3][3])
 	VECCOPY(to[1], from[1]);
 	VECCOPY(to[2], from[2]);
 }
-/* calculate determinant of 4x4 matrix */
+
+/* copy 3x3 matrix */
+DO_INLINE void initdiag_fmatrixS(float to[3][3], float aS)
+{
+	cp_fmatrix(to, ZERO);
+	
+	to[0][0] = aS;
+	to[1][1] = aS;
+	to[2][2] = aS;
+}
+
+/* calculate determinant of 3x3 matrix */
 DO_INLINE float det_fmatrix(float m[3][3])
 {
 	return  m[0][0]*m[1][1]*m[2][2] + m[1][0]*m[2][1]*m[0][2] + m[0][1]*m[1][2]*m[2][0] 
 			-m[0][0]*m[1][2]*m[2][1] - m[0][1]*m[1][0]*m[2][2] - m[2][0]*m[1][1]*m[0][2];
 }
+
 DO_INLINE void inverse_fmatrix(float to[3][3], float from[3][3])
 {
 	unsigned int i, j;
@@ -369,7 +387,7 @@ DO_INLINE void inverse_fmatrix(float to[3][3], float from[3][3])
 
 }
 
-/* 4x4 matrix multiplied by a scalar */
+/* 3x3 matrix multiplied by a scalar */
 /* STATUS: verified */
 DO_INLINE void mul_fmatrix_S(float matrix[3][3], float scalar)
 {
@@ -378,7 +396,7 @@ DO_INLINE void mul_fmatrix_S(float matrix[3][3], float scalar)
 	mul_fvector_S(matrix[2], matrix[2],scalar);
 }
 
-/* a vector multiplied by a 4x4 matrix */
+/* a vector multiplied by a 3x3 matrix */
 /* STATUS: verified */
 DO_INLINE void mul_fvector_fmatrix(float *to, float *from, float matrix[3][3])
 {
@@ -387,7 +405,7 @@ DO_INLINE void mul_fvector_fmatrix(float *to, float *from, float matrix[3][3])
 	to[2] = matrix[0][2]*from[0] + matrix[1][2]*from[1] + matrix[2][2]*from[2];
 }
 
-/* 4x4 matrix multiplied by a vector */
+/* 3x3 matrix multiplied by a vector */
 /* STATUS: verified */
 DO_INLINE void mul_fmatrix_fvector(float *to, float matrix[3][3], float *from)
 {
@@ -395,7 +413,7 @@ DO_INLINE void mul_fmatrix_fvector(float *to, float matrix[3][3], float *from)
 	to[1] = INPR(matrix[1],from);
 	to[2] = INPR(matrix[2],from);
 }
-/* 4x4 matrix multiplied by a 4x4 matrix */
+/* 3x3 matrix multiplied by a 3x3 matrix */
 /* STATUS: verified */
 DO_INLINE void mul_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float matrixB[3][3])
 {
@@ -403,49 +421,49 @@ DO_INLINE void mul_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float ma
 	mul_fvector_fmatrix(to[1], matrixA[1],matrixB);
 	mul_fvector_fmatrix(to[2], matrixA[2],matrixB);
 }
-/* 4x4 matrix addition with 4x4 matrix */
+/* 3x3 matrix addition with 3x3 matrix */
 DO_INLINE void add_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float matrixB[3][3])
 {
 	VECADD(to[0], matrixA[0], matrixB[0]);
 	VECADD(to[1], matrixA[1], matrixB[1]);
 	VECADD(to[2], matrixA[2], matrixB[2]);
 }
-/* 4x4 matrix add-addition with 4x4 matrix */
+/* 3x3 matrix add-addition with 3x3 matrix */
 DO_INLINE void addadd_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float matrixB[3][3])
 {
 	VECADDADD(to[0], matrixA[0], matrixB[0]);
 	VECADDADD(to[1], matrixA[1], matrixB[1]);
 	VECADDADD(to[2], matrixA[2], matrixB[2]);
 }
-/* 4x4 matrix sub-addition with 4x4 matrix */
+/* 3x3 matrix sub-addition with 3x3 matrix */
 DO_INLINE void addsub_fmatrixS_fmatrixS(float to[3][3], float matrixA[3][3], float aS, float matrixB[3][3], float bS)
 {
 	VECADDSUBSS(to[0], matrixA[0], aS, matrixB[0], bS);
 	VECADDSUBSS(to[1], matrixA[1], aS, matrixB[1], bS);
 	VECADDSUBSS(to[2], matrixA[2], aS, matrixB[2], bS);
 }
-/* A -= B + C (4x4 matrix sub-addition with 4x4 matrix) */
+/* A -= B + C (3x3 matrix sub-addition with 3x3 matrix) */
 DO_INLINE void subadd_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float matrixB[3][3])
 {
 	VECSUBADD(to[0], matrixA[0], matrixB[0]);
 	VECSUBADD(to[1], matrixA[1], matrixB[1]);
 	VECSUBADD(to[2], matrixA[2], matrixB[2]);
 }
-/* A -= B*x + C*y (4x4 matrix sub-addition with 4x4 matrix) */
+/* A -= B*x + C*y (3x3 matrix sub-addition with 3x3 matrix) */
 DO_INLINE void subadd_fmatrixS_fmatrixS(float to[3][3], float matrixA[3][3], float aS, float matrixB[3][3], float bS)
 {
 	VECSUBADDSS(to[0], matrixA[0], aS, matrixB[0], bS);
 	VECSUBADDSS(to[1], matrixA[1], aS, matrixB[1], bS);
 	VECSUBADDSS(to[2], matrixA[2], aS, matrixB[2], bS);
 }
-/* A = B - C (4x4 matrix subtraction with 4x4 matrix) */
+/* A = B - C (3x3 matrix subtraction with 3x3 matrix) */
 DO_INLINE void sub_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float matrixB[3][3])
 {
 	VECSUB(to[0], matrixA[0], matrixB[0]);
 	VECSUB(to[1], matrixA[1], matrixB[1]);
 	VECSUB(to[2], matrixA[2], matrixB[2]);
 }
-/* A += B - C (4x4 matrix add-subtraction with 4x4 matrix) */
+/* A += B - C (3x3 matrix add-subtraction with 3x3 matrix) */
 DO_INLINE void addsub_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float matrixB[3][3])
 {
 	VECADDSUB(to[0], matrixA[0], matrixB[0]);
@@ -455,35 +473,35 @@ DO_INLINE void addsub_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float
 /////////////////////////////////////////////////////////////////
 // special functions
 /////////////////////////////////////////////////////////////////
-/* a vector multiplied and added to/by a 4x4 matrix */
+/* a vector multiplied and added to/by a 3x3 matrix */
 DO_INLINE void muladd_fvector_fmatrix(float to[3], float from[3], float matrix[3][3])
 {
 	to[0] += matrix[0][0]*from[0] + matrix[1][0]*from[1] + matrix[2][0]*from[2];
 	to[1] += matrix[0][1]*from[0] + matrix[1][1]*from[1] + matrix[2][1]*from[2];
 	to[2] += matrix[0][2]*from[0] + matrix[1][2]*from[1] + matrix[2][2]*from[2];
 }
-/* 4x4 matrix multiplied and added  to/by a 4x4 matrix  and added to another 4x4 matrix */
+/* 3x3 matrix multiplied and added  to/by a 3x3 matrix  and added to another 3x3 matrix */
 DO_INLINE void muladd_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float matrixB[3][3])
 {
 	muladd_fvector_fmatrix(to[0], matrixA[0],matrixB);
 	muladd_fvector_fmatrix(to[1], matrixA[1],matrixB);
 	muladd_fvector_fmatrix(to[2], matrixA[2],matrixB);
 }
-/* a vector multiplied and sub'd to/by a 4x4 matrix */
+/* a vector multiplied and sub'd to/by a 3x3 matrix */
 DO_INLINE void mulsub_fvector_fmatrix(float to[3], float from[3], float matrix[3][3])
 {
 	to[0] -= matrix[0][0]*from[0] + matrix[1][0]*from[1] + matrix[2][0]*from[2];
 	to[1] -= matrix[0][1]*from[0] + matrix[1][1]*from[1] + matrix[2][1]*from[2];
 	to[2] -= matrix[0][2]*from[0] + matrix[1][2]*from[1] + matrix[2][2]*from[2];
 }
-/* 4x4 matrix multiplied and sub'd  to/by a 4x4 matrix  and added to another 4x4 matrix */
+/* 3x3 matrix multiplied and sub'd  to/by a 3x3 matrix  and added to another 3x3 matrix */
 DO_INLINE void mulsub_fmatrix_fmatrix(float to[3][3], float matrixA[3][3], float matrixB[3][3])
 {
 	mulsub_fvector_fmatrix(to[0], matrixA[0],matrixB);
 	mulsub_fvector_fmatrix(to[1], matrixA[1],matrixB);
 	mulsub_fvector_fmatrix(to[2], matrixA[2],matrixB);
 }
-/* 4x4 matrix multiplied+added by a vector */
+/* 3x3 matrix multiplied+added by a vector */
 /* STATUS: verified */
 DO_INLINE void muladd_fmatrix_fvector(float to[3], float matrix[3][3], float from[3])
 {
@@ -491,7 +509,7 @@ DO_INLINE void muladd_fmatrix_fvector(float to[3], float matrix[3][3], float fro
 	to[1] += INPR(matrix[1],from);
 	to[2] += INPR(matrix[2],from);	
 }
-/* 4x4 matrix multiplied+sub'ed by a vector */
+/* 3x3 matrix multiplied+sub'ed by a vector */
 DO_INLINE void mulsub_fmatrix_fvector(float to[3], float matrix[3][3], float from[3])
 {
 	to[0] -= INPR(matrix[0],from);
@@ -501,7 +519,7 @@ DO_INLINE void mulsub_fmatrix_fvector(float to[3], float matrix[3][3], float fro
 /////////////////////////////////////////////////////////////////
 
 ///////////////////////////
-// SPARSE SYMMETRIC big matrix with 4x4 matrix entries
+// SPARSE SYMMETRIC big matrix with 3x3 matrix entries
 ///////////////////////////
 /* printf a big matrix on console: for debug output */
 void print_bfmatrix(fmatrix3x3 *m3)
@@ -530,12 +548,26 @@ DO_INLINE void del_bfmatrix(fmatrix3x3 *matrix)
 		MEM_freeN (matrix);
 	}
 }
+
 /* copy big matrix */
 DO_INLINE void cp_bfmatrix(fmatrix3x3 *to, fmatrix3x3 *from)
 {	
 	// TODO bounds checking	
 	memcpy(to, from, sizeof(fmatrix3x3) * (from[0].vcount+from[0].scount) );
 }
+
+/* init big matrix */
+// slow in parallel
+DO_INLINE void init_bfmatrix(fmatrix3x3 *matrix, float m3[3][3])
+{
+	unsigned int i;
+
+	for(i = 0; i < matrix[0].vcount+matrix[0].scount; i++)
+	{		
+		cp_fmatrix(matrix[i].m, m3); 
+	}
+}
+
 /* init the diagonal of big matrix */
 // slow in parallel
 DO_INLINE void initdiag_bfmatrix(fmatrix3x3 *matrix, float m3[3][3])
@@ -552,16 +584,7 @@ DO_INLINE void initdiag_bfmatrix(fmatrix3x3 *matrix, float m3[3][3])
 		cp_fmatrix(matrix[j].m, tmatrix); 
 	}
 }
-/* init big matrix */
-DO_INLINE void init_bfmatrix(fmatrix3x3 *matrix, float m3[3][3])
-{
-	unsigned int i;
 
-	for(i = 0; i < matrix[0].vcount+matrix[0].scount; i++)
-	{
-		cp_fmatrix(matrix[i].m, m3); 
-	}
-}
 /* multiply big matrix with scalar*/
 DO_INLINE void mul_bfmatrix_S(fmatrix3x3 *matrix, float scalar)
 {
@@ -707,12 +730,10 @@ DO_INLINE void subadd_bfmatrixS_bfmatrixS( fmatrix3x3 *to, fmatrix3x3 *from, flo
 ///////////////////////////////////////////////////////////////////
 // simulator start
 ///////////////////////////////////////////////////////////////////
-static float I[3][3] = {{1,0,0},{0,1,0},{0,0,1}};
-static float ZERO[3][3] = {{0,0,0}, {0,0,0}, {0,0,0}};
 typedef struct Implicit_Data 
 {
 	lfVector *X, *V, *Xnew, *Vnew, *olddV, *F, *B, *dV, *z;
-	fmatrix3x3 *A, *dFdV, *dFdX, *S, *P, *Pinv, *bigI; 
+	fmatrix3x3 *A, *dFdV, *dFdX, *S, *P, *Pinv, *bigI, *M; 
 } Implicit_Data;
 
 int implicit_init (Object *ob, ClothModifierData *clmd)
@@ -746,6 +767,7 @@ int implicit_init (Object *ob, ClothModifierData *clmd)
 	id->Pinv = create_bfmatrix(cloth->numverts, cloth->numsprings);
 	id->P = create_bfmatrix(cloth->numverts, cloth->numsprings);
 	id->bigI = create_bfmatrix(cloth->numverts, cloth->numsprings); // TODO 0 springs
+	id->M = create_bfmatrix(cloth->numverts, cloth->numsprings);
 	id->X = create_lfvector(cloth->numverts);
 	id->Xnew = create_lfvector(cloth->numverts);
 	id->V = create_lfvector(cloth->numverts);
@@ -759,7 +781,7 @@ int implicit_init (Object *ob, ClothModifierData *clmd)
 	
 	for(i=0;i<cloth->numverts;i++) 
 	{
-		id->A[i].r = id->A[i].c = id->dFdV[i].r = id->dFdV[i].c = id->dFdX[i].r = id->dFdX[i].c = id->P[i].c = id->P[i].r = id->Pinv[i].c = id->Pinv[i].r = id->bigI[i].c = id->bigI[i].r = i;
+		id->A[i].r = id->A[i].c = id->dFdV[i].r = id->dFdV[i].c = id->dFdX[i].r = id->dFdX[i].c = id->P[i].c = id->P[i].r = id->Pinv[i].c = id->Pinv[i].r = id->bigI[i].c = id->bigI[i].r = id->M[i].r = id->M[i].c = i;
 
 		if(verts [i].goal >= SOFTGOALSNAP)
 		{
@@ -767,12 +789,14 @@ int implicit_init (Object *ob, ClothModifierData *clmd)
 			id->S[pinned].c = id->S[pinned].r = i;
 			pinned++;
 		}
+		
+		initdiag_fmatrixS(id->M[i].m, verts[i].mass);
 	}
 
 	// S is special and needs specific vcount and scount
 	id->S[0].vcount = pinned; id->S[0].scount = 0;
 
-	// init springs */
+	// init springs 
 	search = cloth->springs;
 	for(i=0;i<cloth->numsprings;i++) 
 	{
@@ -780,11 +804,11 @@ int implicit_init (Object *ob, ClothModifierData *clmd)
 		
 		// dFdV_start[i].r = big_I[i].r = big_zero[i].r = 
 		id->A[i+cloth->numverts].r = id->dFdV[i+cloth->numverts].r = id->dFdX[i+cloth->numverts].r = 
-				id->P[i+cloth->numverts].r = id->Pinv[i+cloth->numverts].r = id->bigI[i+cloth->numverts].r = spring->ij;
+				id->P[i+cloth->numverts].r = id->Pinv[i+cloth->numverts].r = id->bigI[i+cloth->numverts].r = id->M[i+cloth->numverts].r = spring->ij;
 
 		// dFdV_start[i].c = big_I[i].c = big_zero[i].c = 
 		id->A[i+cloth->numverts].c = id->dFdV[i+cloth->numverts].c = id->dFdX[i+cloth->numverts].c = 
-				id->P[i+cloth->numverts].c = id->Pinv[i+cloth->numverts].c = id->bigI[i+cloth->numverts].c = spring->kl;
+				id->P[i+cloth->numverts].c = id->Pinv[i+cloth->numverts].c = id->bigI[i+cloth->numverts].c = id->M[i+cloth->numverts].c = spring->kl;
 
 		spring->matrix_index = i + cloth->numverts;
 		
@@ -817,6 +841,7 @@ int	implicit_free (ClothModifierData *clmd)
 			del_bfmatrix(id->P);
 			del_bfmatrix(id->Pinv);
 			del_bfmatrix(id->bigI);
+			del_bfmatrix(id->M);
 
 			del_lfvector(id->X);
 			del_lfvector(id->Xnew);
@@ -1037,29 +1062,37 @@ int cg_filtered_pre(lfVector *dv, fmatrix3x3 *lA, lfVector *lB, lfVector *z, fma
 }
 
 // outer product is NOT cross product!!!
-DO_INLINE void dfdx_spring_type1(float to[3][3], float dir[3],float length,float L,float k)
+DO_INLINE void dfdx_spring_type1(float to[3][3], float extent[3], float length, float L, float dot, float k)
 {
 	// dir is unit length direction, rest is spring's restlength, k is spring constant.
 	// return  (outerprod(dir,dir)*k + (I - outerprod(dir,dir))*(k - ((k*L)/length)));
 	float temp[3][3];
+	float temp1 = k*(1.0 - (L/length));	
+	mul_fvectorT_fvectorS(temp, extent, extent, 1.0 / dot);
+	sub_fmatrix_fmatrix(to, I, temp);
+	mul_fmatrix_S(to, temp1);
+	mul_fvectorT_fvectorS(temp, extent, extent, k/ dot);
+	add_fmatrix_fmatrix(to, to, temp);
+	/*
 	mul_fvectorT_fvector(temp, dir, dir);
 	sub_fmatrix_fmatrix(to, I, temp);
 	mul_fmatrix_S(to, k* (1.0f-(L/length)));
 	mul_fmatrix_S(temp, k);
 	add_fmatrix_fmatrix(to, temp, to);
+	*/
 }
 
-DO_INLINE void dfdx_spring_type2(float to[3][3], float dir[3],float length,float L,float k, float cb)
+DO_INLINE void dfdx_spring_type2(float to[3][3], float dir[3], float length, float L, float k, float cb)
 {
 	// return  outerprod(dir,dir)*fbstar_jacobi(length, L, k, cb);
 	mul_fvectorT_fvectorS(to, dir, dir, fbstar_jacobi(length, L, k, cb));
 }
 
-DO_INLINE void dfdv_damp(float to[3][3], float dir[3], float damping)
+DO_INLINE void dfdv_damp(float to[3][3], float ext[3], float damping, float dot)
 {
 	// derivative of force wrt velocity.  
-	// return outerprod(dir,dir) * damping;
-	mul_fvectorT_fvectorS(to, dir, dir, damping);
+	mul_fvectorT_fvectorS(to, ext, ext, damping / dot);
+	
 }
 
 DO_INLINE void dfdx_spring(float to[3][3],  float dir[3],float length,float L,float k)
@@ -1073,6 +1106,7 @@ DO_INLINE void dfdx_spring(float to[3][3],  float dir[3],float length,float L,fl
 	mul_fmatrix_S(to, -k);
 }
 
+// unused atm
 DO_INLINE void dfdx_damp(float to[3][3],  float dir[3],float length,const float vel[3],float rest,float damping)
 {
 	// inner spring damping   vel is the relative velocity  of the endpoints.  
@@ -1086,7 +1120,7 @@ DO_INLINE void dfdx_damp(float to[3][3],  float dir[3],float length,const float
 DO_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s, lfVector *lF, lfVector *X, lfVector *V, fmatrix3x3 *dFdV, fmatrix3x3 *dFdX)
 {
 	float extent[3];
-	float length = 0;
+	float length = 0, dot = 0;
 	float dir[3] = {0,0,0};
 	float vel[3];
 	float k = 0.0f;
@@ -1108,7 +1142,8 @@ DO_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s,
 	// calculate elonglation
 	VECSUB(extent, X[s->kl], X[s->ij]);
 	VECSUB(vel, V[s->kl], V[s->ij]);
-	length = sqrt(INPR(extent, extent));
+	dot = INPR(extent, extent);
+	length = sqrt(dot);
 	
 	s->flags &= ~CLOTH_SPRING_FLAG_NEEDED;
 	
@@ -1144,29 +1179,34 @@ DO_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s,
 			scaling = k + s->stiffness * ABS(clmd->sim_parms->max_struct-k);
 			
 			k = scaling / (clmd->coll_parms->avg_spring_len + FLT_EPSILON);
-			
-			// printf("scaling: %f, stiffness: %f\n", k, s->stiffness);
+			if(G.rt>3)
+			printf("struct scaling: %f\n", k);
 			
 			/*
-			if((s->ij == 109) || (s->kl == 109))
+			if((s->ij == 4) || (s->kl == 4))
 			{
 			printf("length-L: %f, f: %f, len: %f, L: %f\n", length-L, (k*(length-L)), length, L);
 			printf("kl X-x: %f, f-y: %f, f-z: %f\n", X[s->kl][0], X[s->kl][1], X[s->kl][2]);
 			printf("ij X-x: %f, f-y: %f, f-z: %f\n\n", X[s->ij][0], X[s->ij][1], X[s->ij][2]);
-		}
+			}
 			*/
-
-			mul_fvector_S(stretch_force, dir, (k*(length-L))); 
+			
+			// TODO: verify, half verified (couldn't see error)
+			mul_fvector_S(stretch_force, dir, k*(length-L)); 
 
 			VECADD(s->f, s->f, stretch_force);
 
 			// Ascher & Boxman, p.21: Damping only during elonglation
-			mul_fvector_S(damping_force, extent, clmd->sim_parms->Cdis * ((INPR(vel,extent)/length))); 
+			/* VERIFIED */
+			mul_fvector_S(damping_force, extent, clmd->sim_parms->Cdis * (INPR(vel,extent)/dot)); 
 			VECADD(s->f, s->f, damping_force);
-
-			dfdx_spring_type1(s->dfdx, dir,length,L,k);
-
-			dfdv_damp(s->dfdv, dir,clmd->sim_parms->Cdis);
+			
+			// TODO: verify, half verified (couldn't see error)
+			dfdx_spring_type1(s->dfdx, extent, length, L, dot, k);
+			
+			
+			/* VERIFIED */
+			dfdv_damp(s->dfdv, extent, clmd->sim_parms->Cdis, dot);
 		}
 	}
 	else // calculate force of bending springs
@@ -1180,12 +1220,13 @@ DO_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s,
 			scaling = k + s->stiffness * ABS(clmd->sim_parms->max_bend-k);			
 			cb = k = scaling / (20.0*(clmd->coll_parms->avg_spring_len + FLT_EPSILON));
 			
-			// printf("scaling: %f, stiffness: %f\n", k, s->stiffness);
+			if(G.rt>3)
+			printf("bend scaling: %f\n", k);
 
 			mul_fvector_S(bending_force, dir, fbstar(length, L, k, cb));
 			VECADD(s->f, s->f, bending_force);
 
-			dfdx_spring_type2(s->dfdx, dir,length,L,k, cb);
+			dfdx_spring_type2(s->dfdx, dir, length,L, k, cb);
 		}
 	}
 	/*
@@ -1258,7 +1299,7 @@ DO_INLINE void calc_triangle_force(ClothModifierData *clmd, MFace mface, lfVecto
 
 }
 
-void cloth_calc_force(ClothModifierData *clmd, lfVector *lF, lfVector *lX, lfVector *lV, fmatrix3x3 *dFdV, fmatrix3x3 *dFdX, ListBase *effectors, float time)
+void cloth_calc_force(ClothModifierData *clmd, lfVector *lF, lfVector *lX, lfVector *lV, fmatrix3x3 *dFdV, fmatrix3x3 *dFdX, ListBase *effectors, float time, fmatrix3x3 *M)
 {
 	/* Collect forces and derivatives:  F,dFdX,dFdV */
 	Cloth 		*cloth 		= clmd->clothObject;
@@ -1284,6 +1325,14 @@ void cloth_calc_force(ClothModifierData *clmd, lfVector *lF, lfVector *lX, lfVec
 	initdiag_bfmatrix(dFdV, tm2);
 
 	init_lfvector(lF, gravity, numverts);
+	
+	// multiply lF with mass matrix
+	for(i = 0; i < numverts; i++)
+	{
+		float temp[3];
+		VECCOPY(temp, lF[i]);
+		mul_fmatrix_fvector(lF[i], M[i].m, temp);
+	}
 
 	submul_lfvectorS(lF, lV, spring_air, numverts);
 		
@@ -1362,14 +1411,15 @@ void cloth_calc_force(ClothModifierData *clmd, lfVector *lF, lfVector *lX, lfVec
 	// printf("\n");
 }
 
-void simulate_implicit_euler(lfVector *Vnew, lfVector *lX, lfVector *lV, lfVector *lF, fmatrix3x3 *dFdV, fmatrix3x3 *dFdX, float dt, fmatrix3x3 *A, lfVector *B, lfVector *dV, fmatrix3x3 *S, lfVector *z, lfVector *olddV, fmatrix3x3 *P, fmatrix3x3 *Pinv)
+void simulate_implicit_euler(lfVector *Vnew, lfVector *lX, lfVector *lV, lfVector *lF, fmatrix3x3 *dFdV, fmatrix3x3 *dFdX, float dt, fmatrix3x3 *A, lfVector *B, lfVector *dV, fmatrix3x3 *S, lfVector *z, lfVector *olddV, fmatrix3x3 *P, fmatrix3x3 *Pinv, fmatrix3x3 *M)
 {
 	unsigned int numverts = dFdV[0].vcount;
 
 	lfVector *dFdXmV = create_lfvector(numverts);
-	initdiag_bfmatrix(A, I);
 	zero_lfvector(dV, numverts);
-
+	
+	cp_bfmatrix(A, M);
+	
 	subadd_bfmatrixS_bfmatrixS(A, dFdV, dt, dFdX, (dt*dt));
 
 	mul_bfmatrix_lfvector(dFdXmV, dFdX, lV);
@@ -1379,7 +1429,7 @@ void simulate_implicit_euler(lfVector *Vnew, lfVector *lX, lfVector *lV, lfVecto
 	itstart();
 	
 	cg_filtered(dV, A, B, z, S); /* conjugate gradient algorithm to solve Ax=b */
-	// cg_filtered_pre(dV, A, B, z, olddV, P, Pinv, dt);
+	// cg_filtered_pre(dV, A, B, z, S, P, Pinv);
 	
 	itend();
 	// printf("cg_filtered calc time: %f\n", (float)itval());
@@ -1422,19 +1472,19 @@ int implicit_solver (Object *ob, float frame, ClothModifierData *clmd, ListBase
 		effectors= pdInitEffectors(ob,NULL);
 		
 		// calculate 
-		cloth_calc_force(clmd, id->F, id->X, id->V, id->dFdV, id->dFdX, effectors, step );
+		cloth_calc_force(clmd, id->F, id->X, id->V, id->dFdV, id->dFdX, effectors, step, id->M);
 		
 		// printf("F -> x: %f, y: %f; z: %f\n\n", id->F[109][0], id->F[109][1], id->F[109][2]);
-			
-		simulate_implicit_euler(id->Vnew, id->X, id->V, id->F, id->dFdV, id->dFdX, dt, id->A, id->B, id->dV, id->S, id->z, id->olddV, id->P, id->Pinv);
 		
-		add_lfvector_lfvectorS(id->Xnew, id->X, id->Vnew, dt, numverts);
+		simulate_implicit_euler(id->Vnew, id->X, id->V, id->F, id->dFdV, id->dFdX, dt, id->A, id->B, id->dV, id->S, id->z, id->olddV, id->P, id->Pinv, id->M);
 		
+		add_lfvector_lfvectorS(id->Xnew, id->X, id->Vnew, dt, numverts);
 		/*
 		printf("dt: %f\n", dt);
-		printf("Xnew -> x: %f, y: %f; z: %f\n", id->Xnew[109][0], id->Xnew[109][1], id->Xnew[109][2]);
-		printf("X    -> x: %f, y: %f; z: %f\n", id->X[109][0], id->X[109][1], id->X[109][2]);
-		printf("Vnew -> x: %f, y: %f; z: %f\n\n", id->Vnew[109][0], id->Vnew[109][1], id->Vnew[109][2]);
+		printf("Xnew -> x: %f, y: %f; z: %f\n", id->Xnew[4][0], id->Xnew[4][1], id->Xnew[4][2]);
+		printf("X    -> x: %f, y: %f; z: %f\n", id->X[4][0], id->X[4][1], id->X[4][2]);
+		printf("Vnew -> x: %f, y: %f; z: %f\n", id->Vnew[4][0], id->Vnew[3][1], id->Vnew[4][2]);
+		printf("V -> x: %f, y: %f; z: %f\n\n", id->V[4][0], id->V[4][1], id->V[4][2]);
 		*/
 		
 		// clmd->coll_parms->flags &= ~CLOTH_COLLSETTINGS_FLAG_ENABLED;
@@ -1510,8 +1560,8 @@ int implicit_solver (Object *ob, float frame, ClothModifierData *clmd, ListBase
 				cp_lfvector(id->V, id->Vnew, numverts);
 				
 				// calculate 
-				cloth_calc_force(clmd, id->F, id->X, id->V, id->dFdV, id->dFdX, effectors, step);	
-				simulate_implicit_euler(id->Vnew, id->X, id->V, id->F, id->dFdV, id->dFdX, dt / 2.0f, id->A, id->B, id->dV, id->S, id->z, id->olddV, id->P, id->Pinv);
+				cloth_calc_force(clmd, id->F, id->X, id->V, id->dFdV, id->dFdX, effectors, step, id->M);	
+				simulate_implicit_euler(id->Vnew, id->X, id->V, id->F, id->dFdV, id->dFdX, dt / 2.0f, id->A, id->B, id->dV, id->S, id->z, id->olddV, id->P, id->Pinv, id->M);
 			}
 		}
 		else
diff --git a/source/blender/blenkernel/intern/modifier.c b/source/blender/blenkernel/intern/modifier.c
index f5775211d66..049146fb05f 100644
--- a/source/blender/blenkernel/intern/modifier.c
+++ b/source/blender/blenkernel/intern/modifier.c
@@ -5016,12 +5016,7 @@ CustomDataMask clothModifier_requiredDataMask(ModifierData *md)
 	CustomDataMask dataMask = 0;
 
 	/* ask for vertexgroups if we need them */
-	if (((clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_SCALING ) || 
-		     (clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL )) && 
-		     ((clmd->sim_parms->vgroup_mass>0) || 
-		     (clmd->sim_parms->vgroup_struct>0)||
-		     (clmd->sim_parms->vgroup_bend>0)))
-	 		dataMask |= (1 << CD_MDEFORMVERT);
+	dataMask |= (1 << CD_MDEFORMVERT);
 
 	return dataMask;
 }
@@ -5148,12 +5143,13 @@ static void collisionModifier_deformVerts(
 		
 		current_time = bsystem_time ( ob, ( float ) G.scene->r.cfra, 0.0 );
 		
-		// printf("current_time %f, collmd->time %f\n", current_time, collmd->time);
+		if(G.rt > 0)
+			printf("current_time %f, collmd->time %f\n", current_time, collmd->time);
+		
+		numverts = dm->getNumVerts ( dm );
 		
 		if(current_time > collmd->time)
 		{	
-			numverts = dm->getNumVerts ( dm );
-			
 			// check if mesh has changed
 			if(collmd->x && (numverts != collmd->numverts))
 				collisionModifier_freeData((ModifierData *)collmd);
@@ -5221,10 +5217,17 @@ static void collisionModifier_deformVerts(
 			}
 			
 		}
-		else
+		else if(current_time < collmd->time)
 		{	
 			collisionModifier_freeData((ModifierData *)collmd);
 		}
+		else
+		{
+			if(numverts != collmd->numverts)
+			{
+				collisionModifier_freeData((ModifierData *)collmd);
+			}
+		}
 	}
 	
 	if(dm)
diff --git a/source/blender/src/buttons_object.c b/source/blender/src/buttons_object.c
index 0c8768bd195..be81f0139f3 100644
--- a/source/blender/src/buttons_object.c
+++ b/source/blender/src/buttons_object.c
@@ -5104,11 +5104,18 @@ static void object_cloth__enabletoggle(void *ob_v, void *arg2)
 	}
 }
 
+static int _can_cloth_at_all(Object *ob)
+{
+	// list of Yes
+	if ((ob->type==OB_MESH)) return 1;
+	// else deny
+	return 0;
+}
 
 static void object_panel_cloth(Object *ob)
 {
-	uiBlock *block;
-	uiBut *but;
+	uiBlock *block=NULL;
+	uiBut *but=NULL;
 	static int val, val2;
 	ClothModifierData *clmd = (ClothModifierData *)modifiers_findByType(ob, eModifierType_Cloth);
 	
@@ -5117,8 +5124,15 @@ static void object_panel_cloth(Object *ob)
 	uiSetButLock(object_data_is_libdata(ob), ERROR_LIBDATA_MESSAGE);
 	
 	val = (clmd ? 1:0);
-
+	
+	if(!_can_cloth_at_all(ob))
+	{
+		uiDefBut(block, LABEL, 0, "Cloth can be activated on mesh only.",  10,200,300,20, NULL, 0.0, 0, 0, 0, "");
+	}
+	else	
+	{
 	but = uiDefButI(block, TOG, REDRAWBUTSOBJECT, "Cloth",	10,200,130,20, &val, 0, 0, 0, 0, "Sets object to become cloth");
+	}
 
 	uiButSetFunc(but, object_cloth__enabletoggle, ob, NULL);
 	uiDefBut(block, LABEL, 0, "",10,10,300,0, NULL, 0.0, 0, 0, 0, ""); /* tell UI we go to 10,10*/
@@ -5133,6 +5147,8 @@ static void object_panel_cloth(Object *ob)
 		
 		/* GENERAL STUFF */
 		uiClearButLock();
+		if(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_CCACHE_PROTECT) uiSetButLock(1, "Cache is protected");
+		
 		uiBlockBeginAlign(block);
 		uiDefButF(block, NUM, B_CLOTH_RENEW, "StructStiff:",	   10,170,150,20, &clmd->sim_parms->structural, 1.0, 10000.0, 100, 0, "Overall stiffness of structure");
 		uiDefButF(block, NUM, B_CLOTH_RENEW, "BendStiff:",	   160,170,150,20, &clmd->sim_parms->bending, 0.0, 10000.0, 1000, 0, "Wrinkle coefficient (higher = less smaller but more big wrinkles)");
@@ -5237,11 +5253,14 @@ static void object_panel_cloth_II(Object *ob)
 	
 	if(clmd)
 	{	
+		uiClearButLock();
+		if(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_CCACHE_PROTECT) uiSetButLock(1, "Cache is protected");
+		
 		uiDefButI(block, NUM, B_CLOTH_RENEW, "First Frame:",10,160,150,20, &clmd->sim_parms->firstframe, 0, MAXFRAME, 1, 0, "Frame on which the simulation starts");
 		uiDefButI(block, NUM, B_CLOTH_RENEW, "Last Frame:",160,160,150,20, &clmd->sim_parms->lastframe, 0, MAXFRAME, 1, 0, "Frame on which the simulation stops");
 		
 		uiDefBut(block, LABEL, 0, "",10,140,300,20, NULL, 0.0, 0, 0, 0, "");
-		
+		uiClearButLock();
 		if (!G.relbase_valid)
 		{
 			uiDefBut(block, LABEL, 0, "Cache deactivated until file is saved.",  10,120,300,20, NULL, 0.0, 0, 0, 0, "");
@@ -5256,7 +5275,10 @@ static void object_panel_cloth_II(Object *ob)
 			uiDefBut(block, BUT, B_CLOTH_CLEARCACHEFRAME, "From next frame", 200, 100,110,20, NULL, 0.0, 0.0, 10, 0, "Free cloth cache starting from next frame");	
 			uiDefBut(block, LABEL, 0, " ",  10,80,300,20, NULL, 0.0, 0, 0, 0, "");
 		}
-
+		
+		uiClearButLock();
+		if(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_CCACHE_PROTECT) uiSetButLock(1, "Cache is protected");
+		
 		/*
 		TODO: implement this again in cloth!
 		if(length>1) // B_CLOTH_CHANGEPREROLL
@@ -5303,6 +5325,10 @@ static void object_panel_cloth_III(Object *ob)
 		char clmvg [] = "Vertex Groups%t|None%x0|";
 		char clmvg2 [] = "Vertex Groups%t|None%x0|";
 		
+		uiClearButLock();
+		if(clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_CCACHE_PROTECT) uiSetButLock(1, "Cache is protected");
+		
+		
 		uiDefButI(block, NUM, B_DIFF, "Autoprotect Cache From:",10,160,300,20, &clmd->sim_parms->autoprotect, 0.0, MAXFRAME + 1, 1, 0, "Frame on which the simulation gets cache protection enabled automatically (To prevent accidently cleaning it).");
 				
 		uiDefButBitI(block, TOG, CLOTH_SIMSETTINGS_FLAG_SCALING, B_CLOTH_RENEW, "Enable stiffness scaling",10,130,300,20, &clmd->sim_parms->flags, 0, 0, 0, 0, "If enabled, stiffness can be scaled along a weight painted vertex group.");
diff --git a/source/blender/src/editmesh.c b/source/blender/src/editmesh.c
index 94ac17ebd6c..7f9391238dd 100644
--- a/source/blender/src/editmesh.c
+++ b/source/blender/src/editmesh.c
@@ -1187,6 +1187,7 @@ void load_editMesh(void)
 			printf("loadmesh --> CLOTH_SIMSETTINGS_FLAG_RESET\n");
 			/* only reset cloth when no cache was used */
 			clmd->sim_parms->flags |= CLOTH_SIMSETTINGS_FLAG_RESET;
+			clmd->sim_parms->flags |= CLOTH_SIMSETTINGS_FLAG_CCACHE_FFREE;
 			clmd->sim_parms->flags &= ~CLOTH_SIMSETTINGS_FLAG_EDITMODE;
 		}
 	}