diff options
Diffstat (limited to 'source/blender/blenkernel/intern/implicit.c')
| -rw-r--r-- | source/blender/blenkernel/intern/implicit.c | 88 |
1 files changed, 86 insertions, 2 deletions
diff --git a/source/blender/blenkernel/intern/implicit.c b/source/blender/blenkernel/intern/implicit.c index fc5213d5532..0bce71b57eb 100644 --- a/source/blender/blenkernel/intern/implicit.c +++ b/source/blender/blenkernel/intern/implicit.c @@ -1183,7 +1183,8 @@ DO_INLINE void dfdx_spring(float to[3][3], float dir[3],float length,float L,fl //return ( (I-outerprod(dir,dir))*Min(1.0f,rest/length) - I) * -k; mul_fvectorT_fvector(to, dir, dir); sub_fmatrix_fmatrix(to, I, to); - mul_fmatrix_S(to, (((L/length)> 1.0f) ? (1.0f): (L/length))); + + mul_fmatrix_S(to, (L/length)); sub_fmatrix_fmatrix(to, to, I); mul_fmatrix_S(to, -k); } @@ -1218,6 +1219,8 @@ DO_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s, float nulldfdx[3][3]={ {0,0,0}, {0,0,0}, {0,0,0}}; float scaling = 0.0; + + int no_compress = clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_NO_SPRING_COMPRESS; VECCOPY(s->f, nullf); cp_fmatrix(s->dfdx, nulldfdx); @@ -1254,7 +1257,7 @@ DO_INLINE void cloth_calc_spring_force(ClothModifierData *clmd, ClothSpring *s, // calculate force of structural + shear springs if((s->type & CLOTH_SPRING_TYPE_STRUCTURAL) || (s->type & CLOTH_SPRING_TYPE_SHEAR)) { - if(length > L) // only on elonglation + if(length > L || no_compress) { s->flags |= CLOTH_SPRING_FLAG_NEEDED; @@ -1393,6 +1396,84 @@ float calculateVertexWindForce(float wind[3], float vertexnormal[3]) return (INPR(wind, vertexnormal)); } +typedef struct HairGridVert { + float velocity[3]; + float density; +} HairGridVert; +/* Smoothing of hair velocities: + * adapted from + Volumetric Methods for Simulation and Rendering of Hair + by Lena Petrovic, Mark Henne and John Anderson + * Pixar Technical Memo #06-08, Pixar Animation Studios + */ +static void hair_velocity_smoothing(float smoothfac, lfVector *lF, lfVector *lX, lfVector *lV, int numverts) +{ + /* TODO: this is an initial implementation and should be made much better in due time */ + + /* 10x10x10 grid gives nice initial results */ + HairGridVert grid[10][10][10]; + float gmin[3], gmax[3], density; + int v = 0; + int i = 0; + int j = 0; + int k = 0; + lfVector temp; + + INIT_MINMAX(gmin, gmax); + + for(i = 0; i < numverts; i++) + DO_MINMAX(lX[i], gmin, gmax); + + /* initialize grid */ + for(i = 0; i < 10; i++) { + for(j = 0; j < 10; j++) { + for(k = 0; k < 10; k++) { + grid[i][j][k].velocity[0] = 0.0f; + grid[i][j][k].velocity[1] = 0.0f; + grid[i][j][k].velocity[2] = 0.0f; + grid[i][j][k].density = 0.0f; + } + } + } + + /* gather velocities & density */ + for(v = 0; v < numverts; v++) { + i = (int)( (lX[v][0] - gmin[0]) / (gmax[0] - gmin[0]) * 9.99f ); + j = (int)( (lX[v][1] - gmin[1]) / (gmax[1] - gmin[1]) * 9.99f ); + k = (int)( (lX[v][2] - gmin[2]) / (gmax[2] - gmin[2]) * 9.99f ); + + grid[i][j][k].velocity[0] += lV[v][0]; + grid[i][j][k].velocity[1] += lV[v][1]; + grid[i][j][k].velocity[2] += lV[v][2]; + grid[i][j][k].density += 1.0f; + } + + /* divide velocity with density */ + for(i = 0; i < 10; i++) { + for(j = 0; j < 10; j++) { + for(k = 0; k < 10; k++) { + density = grid[i][j][k].density; + if(density > 0.0f) { + grid[i][j][k].velocity[0] /= density; + grid[i][j][k].velocity[1] /= density; + grid[i][j][k].velocity[2] /= density; + } + } + } + } + + /* calculate forces */ + for(v = 0; v < numverts; v++) { + i = (int)( (lX[v][0] - gmin[0]) / (gmax[0] - gmin[0]) * 9.99f ); + j = (int)( (lX[v][1] - gmin[1]) / (gmax[1] - gmin[1]) * 9.99f ); + k = (int)( (lX[v][2] - gmin[2]) / (gmax[2] - gmin[2]) * 9.99f ); + + /* 2.0f is an experimental value that seems to give good results */ + lF[v][0] += 2.0f * smoothfac * (grid[i][j][k].velocity[0] - lV[v][0]); + lF[v][1] += 2.0f * smoothfac * (grid[i][j][k].velocity[1] - lV[v][1]); + lF[v][2] += 2.0f * smoothfac * (grid[i][j][k].velocity[2] - lV[v][2]); + } +} static void cloth_calc_force(ClothModifierData *clmd, float frame, lfVector *lF, lfVector *lX, lfVector *lV, fmatrix3x3 *dFdV, fmatrix3x3 *dFdX, ListBase *effectors, float time, fmatrix3x3 *M) { /* Collect forces and derivatives: F,dFdX,dFdV */ @@ -1416,6 +1497,9 @@ static void cloth_calc_force(ClothModifierData *clmd, float frame, lfVector *lF, init_lfvector(lF, gravity, numverts); + if(clmd->sim_parms->velocity_smooth > 0.0f) + hair_velocity_smoothing(clmd->sim_parms->velocity_smooth, lF, lX, lV, numverts); + /* multiply lF with mass matrix // force = mass * acceleration (in this case: gravity) */ |