Main cloth force calculation function outside of implicit core code.
Still misses spring forces.
This commit is contained in:
@@ -1528,227 +1528,6 @@ DO_INLINE void cloth_apply_spring_force(ClothModifierData *UNUSED(clmd), ClothSp
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}
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}
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static void CalcFloat( float *v1, float *v2, float *v3, float *n)
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{
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float n1[3], n2[3];
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n1[0] = v1[0]-v2[0];
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n2[0] = v2[0]-v3[0];
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n1[1] = v1[1]-v2[1];
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n2[1] = v2[1]-v3[1];
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n1[2] = v1[2]-v2[2];
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n2[2] = v2[2]-v3[2];
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n[0] = n1[1]*n2[2]-n1[2]*n2[1];
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n[1] = n1[2]*n2[0]-n1[0]*n2[2];
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n[2] = n1[0]*n2[1]-n1[1]*n2[0];
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}
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static void CalcFloat4( float *v1, float *v2, float *v3, float *v4, float *n)
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{
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/* real cross! */
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float n1[3], n2[3];
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n1[0] = v1[0]-v3[0];
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n1[1] = v1[1]-v3[1];
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n1[2] = v1[2]-v3[2];
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n2[0] = v2[0]-v4[0];
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n2[1] = v2[1]-v4[1];
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n2[2] = v2[2]-v4[2];
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n[0] = n1[1]*n2[2]-n1[2]*n2[1];
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n[1] = n1[2]*n2[0]-n1[0]*n2[2];
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n[2] = n1[0]*n2[1]-n1[1]*n2[0];
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}
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static float calculateVertexWindForce(const float wind[3], const float vertexnormal[3])
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{
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return dot_v3v3(wind, vertexnormal);
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}
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static void cloth_calc_force(ClothModifierData *clmd, float UNUSED(frame), lfVector *lF, lfVector *lX, lfVector *lV, fmatrix3x3 *dFdV, fmatrix3x3 *dFdX, ListBase *effectors, float time, fmatrix3x3 *M)
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{
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/* Collect forces and derivatives: F, dFdX, dFdV */
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Cloth *cloth = clmd->clothObject;
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ClothVertex *verts = cloth->verts;
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RootTransform *roots = cloth->implicit->root;
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unsigned int i = 0;
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float drag = clmd->sim_parms->Cvi * 0.01f; /* viscosity of air scaled in percent */
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float gravity[3] = {0.0f, 0.0f, 0.0f};
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MFace *mfaces = cloth->mfaces;
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unsigned int numverts = cloth->numverts;
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LinkNode *search;
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lfVector *winvec;
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EffectedPoint epoint;
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/* initialize forces to zero */
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zero_lfvector(lF, numverts);
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init_bfmatrix(dFdX, ZERO);
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init_bfmatrix(dFdV, ZERO);
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#ifdef CLOTH_FORCE_GRAVITY
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/* global acceleration (gravitation) */
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if (clmd->scene->physics_settings.flag & PHYS_GLOBAL_GRAVITY) {
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copy_v3_v3(gravity, clmd->scene->physics_settings.gravity);
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mul_fvector_S(gravity, gravity, 0.001f * clmd->sim_parms->effector_weights->global_gravity); /* scale gravity force */
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}
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/* multiply lF with mass matrix
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* force = mass * acceleration (in this case: gravity)
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*/
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for (i = 0; i < numverts; i++) {
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float g[3];
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acc_world_to_root(g, lX[i], lV[i], gravity, &roots[i]);
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mul_m3_v3(M[i].m, g);
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add_v3_v3(lF[i], g);
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}
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#else
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zero_lfvector(lF, numverts);
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#endif
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// XXX TODO
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// hair_volume_forces(clmd, lF, lX, lV, numverts);
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#ifdef CLOTH_FORCE_DRAG
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/* set dFdX jacobi matrix diagonal entries to -spring_air */
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for (i = 0; i < numverts; i++) {
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dFdV[i].m[0][0] -= drag;
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dFdV[i].m[1][1] -= drag;
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dFdV[i].m[2][2] -= drag;
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}
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submul_lfvectorS(lF, lV, drag, numverts);
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for (i = 0; i < numverts; i++) {
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#if 1
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float tmp[3][3];
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/* NB: uses root space velocity, no need to transform */
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madd_v3_v3fl(lF[i], lV[i], -drag);
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copy_m3_m3(tmp, I);
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mul_m3_fl(tmp, -drag);
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add_m3_m3m3(dFdV[i].m, dFdV[i].m, tmp);
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#else
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float f[3], tmp[3][3], drag_dfdv[3][3], t[3];
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mul_v3_v3fl(f, lV[i], -drag);
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force_world_to_root(t, lX[i], lV[i], f, verts[i].mass, &roots[i]);
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add_v3_v3(lF[i], t);
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copy_m3_m3(drag_dfdv, I);
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mul_m3_fl(drag_dfdv, -drag);
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dfdv_world_to_root(tmp, drag_dfdv, verts[i].mass, &roots[i]);
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add_m3_m3m3(dFdV[i].m, dFdV[i].m, tmp);
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#endif
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}
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#endif
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/* handle external forces like wind */
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if (effectors) {
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// 0 = force, 1 = normalized force
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winvec = create_lfvector(cloth->numverts);
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if (!winvec)
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printf("winvec: out of memory in implicit.c\n");
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// precalculate wind forces
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for (i = 0; i < cloth->numverts; i++) {
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pd_point_from_loc(clmd->scene, (float*)lX[i], (float*)lV[i], i, &epoint);
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pdDoEffectors(effectors, NULL, clmd->sim_parms->effector_weights, &epoint, winvec[i], NULL);
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}
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for (i = 0; i < cloth->numfaces; i++) {
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float trinormal[3] = {0, 0, 0}; // normalized triangle normal
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float triunnormal[3] = {0, 0, 0}; // not-normalized-triangle normal
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float tmp[3] = {0, 0, 0};
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float factor = (mfaces[i].v4) ? 0.25 : 1.0 / 3.0;
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factor *= 0.02f;
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// calculate face normal
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if (mfaces[i].v4)
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CalcFloat4(lX[mfaces[i].v1], lX[mfaces[i].v2], lX[mfaces[i].v3], lX[mfaces[i].v4], triunnormal);
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else
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CalcFloat(lX[mfaces[i].v1], lX[mfaces[i].v2], lX[mfaces[i].v3], triunnormal);
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normalize_v3_v3(trinormal, triunnormal);
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// add wind from v1
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copy_v3_v3(tmp, trinormal);
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mul_v3_fl(tmp, calculateVertexWindForce(winvec[mfaces[i].v1], triunnormal));
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VECADDS(lF[mfaces[i].v1], lF[mfaces[i].v1], tmp, factor);
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// add wind from v2
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copy_v3_v3(tmp, trinormal);
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mul_v3_fl(tmp, calculateVertexWindForce(winvec[mfaces[i].v2], triunnormal));
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VECADDS(lF[mfaces[i].v2], lF[mfaces[i].v2], tmp, factor);
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// add wind from v3
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copy_v3_v3(tmp, trinormal);
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mul_v3_fl(tmp, calculateVertexWindForce(winvec[mfaces[i].v3], triunnormal));
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VECADDS(lF[mfaces[i].v3], lF[mfaces[i].v3], tmp, factor);
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// add wind from v4
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if (mfaces[i].v4) {
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copy_v3_v3(tmp, trinormal);
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mul_v3_fl(tmp, calculateVertexWindForce(winvec[mfaces[i].v4], triunnormal));
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VECADDS(lF[mfaces[i].v4], lF[mfaces[i].v4], tmp, factor);
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}
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}
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/* Hair has only edges */
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if (cloth->numfaces == 0) {
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ClothSpring *spring;
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float edgevec[3] = {0, 0, 0}; //edge vector
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float edgeunnormal[3] = {0, 0, 0}; // not-normalized-edge normal
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float tmp[3] = {0, 0, 0};
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float factor = 0.01;
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search = cloth->springs;
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while (search) {
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spring = search->link;
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if (spring->type == CLOTH_SPRING_TYPE_STRUCTURAL) {
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sub_v3_v3v3(edgevec, (float*)lX[spring->ij], (float*)lX[spring->kl]);
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project_v3_v3v3(tmp, winvec[spring->ij], edgevec);
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sub_v3_v3v3(edgeunnormal, winvec[spring->ij], tmp);
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/* hair doesn't stretch too much so we can use restlen pretty safely */
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VECADDS(lF[spring->ij], lF[spring->ij], edgeunnormal, spring->restlen * factor);
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project_v3_v3v3(tmp, winvec[spring->kl], edgevec);
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sub_v3_v3v3(edgeunnormal, winvec[spring->kl], tmp);
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VECADDS(lF[spring->kl], lF[spring->kl], edgeunnormal, spring->restlen * factor);
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}
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search = search->next;
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}
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}
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del_lfvector(winvec);
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}
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// calculate spring forces
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search = cloth->springs;
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while (search) {
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// only handle active springs
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ClothSpring *spring = search->link;
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if (!(spring->flags & CLOTH_SPRING_FLAG_DEACTIVATE))
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cloth_calc_spring_force(clmd, search->link, lF, lX, lV, dFdV, dFdX, time);
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search = search->next;
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}
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// apply spring forces
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search = cloth->springs;
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while (search) {
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// only handle active springs
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ClothSpring *spring = search->link;
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if (!(spring->flags & CLOTH_SPRING_FLAG_DEACTIVATE))
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cloth_apply_spring_force(clmd, search->link, lF, lX, lV, dFdV, dFdX);
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search = search->next;
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}
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// printf("\n");
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}
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bool BPH_mass_spring_solve(Implicit_Data *data, float dt)
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{
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unsigned int numverts = data->dFdV[0].vcount;
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@@ -1925,4 +1704,120 @@ void BPH_mass_spring_add_constraint_ndof2(Implicit_Data *data, int index, const
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add_v3_v3(data->z[index], u);
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}
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void BPH_mass_spring_force_clear(Implicit_Data *data)
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{
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int numverts = data->M[0].vcount;
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zero_lfvector(data->F, numverts);
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init_bfmatrix(data->dFdX, ZERO);
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init_bfmatrix(data->dFdV, ZERO);
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}
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void BPH_mass_spring_force_gravity(Implicit_Data *data, const float g[3])
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{
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int i, numverts = data->M[0].vcount;
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/* multiply F with mass matrix
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* force = mass * acceleration (in this case: gravity)
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*/
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for (i = 0; i < numverts; i++) {
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float f[3];
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acc_world_to_root(f, data->X[i], data->V[i], g, &data->root[i]);
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mul_m3_v3(data->M[i].m, f);
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add_v3_v3(data->F[i], f);
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}
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}
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void BPH_mass_spring_force_drag(Implicit_Data *data, float drag)
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{
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int i, numverts = data->M[0].vcount;
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for (i = 0; i < numverts; i++) {
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#if 1
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float tmp[3][3];
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/* NB: uses root space velocity, no need to transform */
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madd_v3_v3fl(data->F[i], data->V[i], -drag);
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copy_m3_m3(tmp, I);
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mul_m3_fl(tmp, -drag);
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add_m3_m3m3(data->dFdV[i].m, data->dFdV[i].m, tmp);
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#else
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float f[3], tmp[3][3], drag_dfdv[3][3], t[3];
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mul_v3_v3fl(f, data->V[i], -drag);
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force_world_to_root(t, data->X[i], data->V[i], f, verts[i].mass, &data->root[i]);
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add_v3_v3(data->F[i], t);
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copy_m3_m3(drag_dfdv, I);
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mul_m3_fl(drag_dfdv, -drag);
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dfdv_world_to_root(tmp, drag_dfdv, verts[i].mass, &data->root[i]);
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add_m3_m3m3(data->dFdV[i].m, data->dFdV[i].m, tmp);
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#endif
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}
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}
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static float calc_nor_area_tri(float nor[3], const float v1[3], const float v2[3], const float v3[3])
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{
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float n1[3], n2[3];
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sub_v3_v3v3(n1, v1, v2);
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sub_v3_v3v3(n2, v2, v3);
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cross_v3_v3v3(nor, n1, n2);
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return normalize_v3(nor);
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}
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static float calc_nor_area_quad(float nor[3], const float v1[3], const float v2[3], const float v3[3], const float v4[3])
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{
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float n1[3], n2[3];
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sub_v3_v3v3(n1, v1, v3);
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sub_v3_v3v3(n2, v2, v4);
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cross_v3_v3v3(nor, n1, n2);
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return normalize_v3(nor);
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}
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/* XXX does not support force jacobians yet, since the effector system does not provide them either */
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void BPH_mass_spring_force_face_wind(Implicit_Data *data, int v1, int v2, int v3, int v4, const float (*winvec)[3])
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{
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const float effector_scale = 0.02f;
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float nor[3], area;
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float factor;
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// calculate face normal and area
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if (v4) {
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area = calc_nor_area_quad(nor, data->X[v1], data->X[v2], data->X[v3], data->X[v4]);
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factor = effector_scale * area * 0.25f;
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}
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else {
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area = calc_nor_area_tri(nor, data->X[v1], data->X[v2], data->X[v3]);
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factor = effector_scale * area / 3.0f;
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}
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madd_v3_v3fl(data->F[v1], nor, factor * dot_v3v3(winvec[v1], nor));
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madd_v3_v3fl(data->F[v2], nor, factor * dot_v3v3(winvec[v2], nor));
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madd_v3_v3fl(data->F[v3], nor, factor * dot_v3v3(winvec[v3], nor));
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if (v4)
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madd_v3_v3fl(data->F[v4], nor, factor * dot_v3v3(winvec[v4], nor));
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}
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void BPH_mass_spring_force_edge_wind(struct Implicit_Data *data, int v1, int v2, const float (*winvec)[3])
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{
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const float effector_scale = 0.01;
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const float *win1 = winvec[v1];
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const float *win2 = winvec[v2];
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float win_ortho[3], dir[3], length;
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sub_v3_v3v3(dir, data->X[v1], data->X[v2]);
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length = normalize_v3(dir);
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madd_v3_v3v3fl(win_ortho, win1, dir, -dot_v3v3(win1, dir));
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madd_v3_v3fl(data->F[v1], win_ortho, effector_scale * length);
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madd_v3_v3v3fl(win_ortho, win2, dir, -dot_v3v3(win2, dir));
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madd_v3_v3fl(data->F[v2], win_ortho, effector_scale * length);
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}
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#endif /* IMPLICIT_SOLVER_BLENDER */
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