// Copyright 2021 DeepMind Technologies Limited // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. #include "engine/engine_collision_convex.h" #include #include #include #include #include #include #include #include "engine/engine_collision_gjk.h" #include "engine/engine_collision_primitive.h" #include "engine/engine_io.h" #include "engine/engine_util_blas.h" #include "engine/engine_util_errmem.h" #include "engine/engine_util_misc.h" #include "engine/engine_util_spatial.h" // allocate callback for EPA in nativeccd static void* ccd_allocate(void* data, size_t nbytes) { mj_markStack((mjData*)data); return mj_stackAllocByte((mjData*)data, nbytes, sizeof(mjtNum)); } // free callback for EPA in nativeccd static void ccd_free(void* data, void* buffer) { mj_freeStack((mjData*)data); } // call libccd or nativeccd to recover penetration info static int mjc_penetration(const mjModel* m, mjCCDObj* obj1, mjCCDObj* obj2, const ccd_t* ccd, ccd_real_t* depth, ccd_vec3_t* dir, ccd_vec3_t* pos) { // fallback to MPR if (mjDISABLED(mjDSBL_NATIVECCD)) { return ccdMPRPenetration(obj1, obj2, ccd, depth, dir, pos); } mjCCDConfig config; mjCCDStatus status; // set config config.max_iterations = ccd->max_iterations, config.tolerance = ccd->mpr_tolerance, config.max_contacts = 1; config.dist_cutoff = 0; // no geom distances needed config.context = (void*)obj1->data; config.alloc = ccd_allocate; config.free = ccd_free; mjtNum dist = mjc_ccd(&config, &status, obj1, obj2); if (dist < 0) { if (depth) *depth = -dist; if (dir) { mju_sub3(dir->v, status.x1, status.x2); mju_normalize3(dir->v); } if (pos) { pos->v[0] = 0.5 * (status.x1[0] + status.x2[0]); pos->v[1] = 0.5 * (status.x1[1] + status.x2[1]); pos->v[2] = 0.5 * (status.x1[2] + status.x2[2]); } return 0; } if (depth) *depth = 0; if (dir) mju_zero3(dir->v); if (pos) mju_zero3(dir->v); return 1; } // ccd center function void mjccd_center(const void *obj, ccd_vec3_t *center) { mjc_center(center->v, (const mjCCDObj*) obj); } // center function for convex collision algorithms void mjc_center(mjtNum res[3], const mjCCDObj *obj) { int g = obj->geom; int f = obj->flex; int e = obj->elem; int v = obj->vert; // return geom position if (g >= 0) { mju_copy3(res, obj->data->geom_xpos + 3*g); } // return flex element position else if (e >= 0) { mju_copy3(res, obj->data->flexelem_aabb + 6*(obj->model->flex_elemadr[f]+e)); } // return flex vertex position else { mju_copy3(res, obj->data->flexvert_xpos + 3*(obj->model->flex_vertadr[f]+v)); } } // prism center function static void mjc_prism_center(mjtNum res[3], const mjCCDObj* obj) { // compute mean mju_zero3(res); for (int i=0; i < 6; i++) { mju_addTo3(res, obj->prism[i]); } mju_scl3(res, res, 1.0/6.0); } // ccd prism center function static void mjccd_prism_center(const void *obj, ccd_vec3_t *center) { mjc_prism_center(center->v, (const mjCCDObj*) obj); } // ------------------------------------ Support functions ----------------------------------------- // transform a vector from global to local frame static inline void mulMatTVec3(mjtNum res[3], const mjtNum mat[9], const mjtNum dir[3]) { // perform matT * dir res[0] = mat[0]*dir[0] + mat[3]*dir[1] + mat[6]*dir[2]; res[1] = mat[1]*dir[0] + mat[4]*dir[1] + mat[7]*dir[2]; res[2] = mat[2]*dir[0] + mat[5]*dir[1] + mat[8]*dir[2]; } // transform a vector from local to global frame static inline void localToGlobal(mjtNum res[3], const mjtNum mat[9], const mjtNum dir[3], const mjtNum pos[3]) { // perform mat * dir + pos res[0] = mat[0]*dir[0] + mat[1]*dir[1] + mat[2]*dir[2]; res[1] = mat[3]*dir[0] + mat[4]*dir[1] + mat[5]*dir[2]; res[2] = mat[6]*dir[0] + mat[7]*dir[1] + mat[8]*dir[2]; res[0] += pos[0]; res[1] += pos[1]; res[2] += pos[2]; } // point support function void mjc_pointSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjtNum* pos = obj->data->geom_xpos + 3*obj->geom; res[0] = pos[0]; res[1] = pos[1]; res[2] = pos[2]; } // sphere support function static void mjc_sphereSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; // sphere data const mjtNum* pos = d->geom_xpos + 3*obj->geom; mjtNum radius = m->geom_size[3*obj->geom]; res[0] = radius*dir[0] + pos[0]; res[1] = radius*dir[1] + pos[1]; res[2] = radius*dir[2] + pos[2]; } // line support function (capsule) void mjc_lineSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; // capsule data int i = 3*obj->geom; const mjtNum* mat = d->geom_xmat + 3*i; const mjtNum* pos = d->geom_xpos + i; mjtNum length = m->geom_size[i+1]; // rotate dir to geom local frame mjtNum local_dir[3], tmp[3]; mulMatTVec3(local_dir, mat, dir); tmp[0] = 0; tmp[1] = 0; tmp[2] = (local_dir[2] >= 0 ? length : -length); // transform result to global frame localToGlobal(res, mat, tmp, pos); } // capsule support function static void mjc_capsuleSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; // capsule data int i = 3*obj->geom; const mjtNum* mat = d->geom_xmat + 3*i; const mjtNum* pos = d->geom_xpos + i; mjtNum radius = m->geom_size[i]; mjtNum length = m->geom_size[i+1]; // rotate dir to geom local frame mjtNum local_dir[3], tmp[3]; mulMatTVec3(local_dir, mat, dir); // start with sphere tmp[0] = local_dir[0] * radius; tmp[1] = local_dir[1] * radius; tmp[2] = local_dir[2] * radius; // add cylinder contribution tmp[2] += (local_dir[2] >= 0 ? length : -length); // transform result to global frame localToGlobal(res, mat, tmp, pos); } // ellipsoid support function static void mjc_ellipsoidSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; // ellipsoid data int i = 3*obj->geom; const mjtNum* mat = d->geom_xmat + 3*i; const mjtNum* pos = d->geom_xpos + i; const mjtNum* size = m->geom_size + i; // rotate dir to geom local frame mjtNum local_dir[3], tmp[3]; mulMatTVec3(local_dir, mat, dir); // find support point on unit sphere: scale dir by ellipsoid sizes tmp[0] = local_dir[0] * size[0]; tmp[1] = local_dir[1] * size[1]; tmp[2] = local_dir[2] * size[2]; mjtNum norm = mju_sqrt(tmp[0]*tmp[0] + tmp[1]*tmp[1] + tmp[2]*tmp[2]); // try normalizing and transform to ellipsoid if (norm < mjMINVAL) { tmp[0] = size[0]; tmp[1] = 0; tmp[2] = 0; } else { mjtNum norm_inv = 1/norm; tmp[0] *= norm_inv * size[0]; tmp[1] *= norm_inv * size[1]; tmp[2] *= norm_inv * size[2]; } // transform result to global frame localToGlobal(res, mat, tmp, pos); } // cylinder support function static void mjc_cylinderSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; // cylinder data int i = 3*obj->geom; const mjtNum* mat = d->geom_xmat + 3*i; const mjtNum* pos = d->geom_xpos + i; const mjtNum* size = m->geom_size + i; // rotate dir to geom local frame mjtNum local_dir[3], tmp[3]; mulMatTVec3(local_dir, mat, dir); mjtNum n = local_dir[0]*local_dir[0] + local_dir[1]*local_dir[1]; if (n > mjMINVAL*mjMINVAL) { n = size[0] / mju_sqrt(n); tmp[0] = local_dir[0] * n; tmp[1] = local_dir[1] * n; } else { tmp[0] = tmp[1] = 0; } // set result in Z direction tmp[2] = mju_sign(local_dir[2]) * size[1]; // transform result to global frame localToGlobal(res, mat, tmp, pos); } // box support function static void mjc_boxSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; // box data int i = 3*obj->geom; const mjtNum* mat = d->geom_xmat + 3*i; const mjtNum* pos = d->geom_xpos + i; const mjtNum* size = m->geom_size + i; // rotate dir to geom local frame mjtNum local_dir[3], tmp[3]; mulMatTVec3(local_dir, mat, dir); // find support point in local frame tmp[0] = (local_dir[0] >= 0 ? 1 : -1) * size[0]; tmp[1] = (local_dir[1] >= 0 ? 1 : -1) * size[1]; tmp[2] = (local_dir[2] >= 0 ? 1 : -1) * size[2]; // mark the index of the corner of the box for fast lookup obj->vertindex = 0; if (tmp[0] > 0) obj->vertindex |= 1; if (tmp[1] > 0) obj->vertindex |= 2; if (tmp[2] > 0) obj->vertindex |= 4; // transform support point to global frame localToGlobal(res, mat, tmp, pos); } // dot product between mjtNum and float static inline mjtNum dot3f(const mjtNum a[3], const float b[3]) { return a[0]*(mjtNum)b[0] + a[1]*(mjtNum)b[1] + a[2]*(mjtNum)b[2]; } // mesh support function via exhaustive search static void mjc_meshSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; // mesh data int g = obj->geom; const mjtNum* mat = d->geom_xmat+9*g; const mjtNum* pos = d->geom_xpos+3*g; float* verts = m->mesh_vert + 3*m->mesh_vertadr[m->geom_dataid[g]]; int nverts = m->mesh_vertnum[m->geom_dataid[g]]; mjtNum local_dir[3]; mulMatTVec3(local_dir, mat, dir); mjtNum max = -FLT_MAX; int imax = 0; // used cached results from previous search if (obj->vertindex >= 0) { imax = obj->vertindex; max = dot3f(local_dir, verts + 3*imax); } // search all vertices, find maximum dot product for (int i=0; i < nverts; i++) { mjtNum vdot = dot3f(local_dir, verts + 3*i); // update max if (vdot > max) { max = vdot; imax = i; } } // record vertex index of maximum obj->vertindex = imax; local_dir[0] = (mjtNum)verts[3*imax + 0]; local_dir[1] = (mjtNum)verts[3*imax + 1]; local_dir[2] = (mjtNum)verts[3*imax + 2]; // transform result to global frame localToGlobal(res, mat, local_dir, pos); } // mesh support function via hill climbing static void mjc_hillclimbSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; // get mesh info int g = obj->geom; int graphadr = m->mesh_graphadr[m->geom_dataid[g]]; int numvert = m->mesh_graph[graphadr]; int* vert_edgeadr = m->mesh_graph + graphadr + 2; int* vert_globalid = m->mesh_graph + graphadr + 2 + numvert; int* edge_localid = m->mesh_graph + graphadr + 2 + 2*numvert; float* verts = m->mesh_vert + 3*m->mesh_vertadr[m->geom_dataid[g]]; const mjtNum* mat = d->geom_xmat + 9*g; const mjtNum* pos = d->geom_xpos+3*g; // rotate dir to geom local frame mjtNum local_dir[3]; mulMatTVec3(local_dir, mat, dir); // hillclimb until no change mjtNum max = -FLT_MAX; int prev = -1, imax = obj->meshindex < 0 ? 0 : obj->meshindex; do { prev = imax; for (int i = vert_edgeadr[imax]; edge_localid[i] >= 0; i++) { int idx = 3*vert_globalid[edge_localid[i]]; mjtNum vdot = dot3f(local_dir, verts + idx); if (vdot > max) { max = vdot; imax = edge_localid[i]; // update maximum vertex index } } } while (imax != prev); // record vertex index of maximum (local id) obj->meshindex = imax; // get resulting support vertex imax = 3*vert_globalid[imax]; obj->vertindex = imax / 3; local_dir[0] = (mjtNum)verts[imax + 0]; local_dir[1] = (mjtNum)verts[imax + 1]; local_dir[2] = (mjtNum)verts[imax + 2]; // transform result to global frame localToGlobal(res, mat, local_dir, pos); } // prism support function static void mjc_prism_support(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { int istart, ibest; mjtNum best, tmp; // find best vertex in halfspace determined by dir.z istart = dir[2] < 0 ? 0 : 3; ibest = istart; best = mju_dot3(obj->prism[istart], dir); for (int i=istart+1; i < istart+3; i++) { if ((tmp = mju_dot3(obj->prism[i], dir)) > best) { ibest = i; best = tmp; } } // copy best point mju_copy3(res, obj->prism[ibest]); } // flex support function static void mjc_flexSupport(mjtNum res[3], mjCCDObj* obj, const mjtNum dir[3]) { const mjModel* m = obj->model; const mjData* d = obj->data; int f = obj->flex; int dim = m->flex_dim[f]; // flex element if (obj->elem >= 0) { int e = obj->elem; const int* edata = m->flex_elem + m->flex_elemdataadr[f] + e*(dim+1); const mjtNum* vert = d->flexvert_xpos + 3*m->flex_vertadr[f]; // find element vertex with largest projection along dir mju_copy3(res, vert+3*edata[0]); mjtNum best = mju_dot3(res, dir); for (int i=1; i <= dim; i++) { mjtNum dot = mju_dot3(vert+3*edata[i], dir); // better vertex found: assign if (dot > best) { best = dot; mju_copy3(res, vert+3*edata[i]); } } // add radius and margin/2 mju_addToScl3(res, dir, m->flex_radius[f] + 0.5*obj->margin); return; } // flex vertex else { const mjtNum* vert = d->flexvert_xpos + 3*(m->flex_vertadr[f] + obj->vert); mju_addScl3(res, vert, dir, m->flex_radius[f] + 0.5*obj->margin); return; } } // libccd support function void mjccd_support(const void *_obj, const ccd_vec3_t *_dir, ccd_vec3_t *vec) { mjCCDObj *obj = (mjCCDObj *)_obj; mjtNum *res = vec->v; const mjtNum *dir = _dir->v; const mjModel* m = obj->model; const mjData* d = obj->data; int g = obj->geom; if (g < 0) { int f = obj->flex; int dim = m->flex_dim[f]; // flex element if (obj->elem >= 0) { int e = obj->elem; const int* edata = m->flex_elem + m->flex_elemdataadr[f] + e*(dim+1); const mjtNum* vert = d->flexvert_xpos + 3*m->flex_vertadr[f]; // find element vertex with largest projection along dir mju_copy3(res, vert+3*edata[0]); mjtNum best = mju_dot3(res, dir); for (int i=1; i <= dim; i++) { mjtNum dot = mju_dot3(vert+3*edata[i], dir); // better vertex found: assign if (dot > best) { best = dot; mju_copy3(res, vert+3*edata[i]); } } // add radius and margin/2 mju_addToScl3(res, dir, m->flex_radius[f] + 0.5*obj->margin); return; } // flex vertex else { const mjtNum* vert = d->flexvert_xpos + 3*(m->flex_vertadr[f] + obj->vert); mju_addScl3(res, vert, dir, m->flex_radius[f] + 0.5*obj->margin); return; } } float* vertdata; int ibest, graphadr, numvert, change, locid; int *vert_edgeadr, *vert_globalid, *edge_localid; mjtNum tmp, vdot; const mjtNum* size = m->geom_size+3*g; // geom sizes mjtNum local_dir[3]; // direction in geom local frame // rotate dir to geom local frame mju_mulMatTVec3(local_dir, d->geom_xmat+9*g, dir); // compute result according to geom type switch ((mjtGeom) obj->geom_type) { case mjGEOM_SPHERE: mju_scl3(res, local_dir, size[0]); break; case mjGEOM_CAPSULE: // start with sphere mju_scl3(res, local_dir, size[0]); // add cylinder contribution res[2] += mju_sign(local_dir[2]) * size[1]; break; case mjGEOM_ELLIPSOID: // find support point on unit sphere: scale dir by ellipsoid sizes and renormalize for (int i=0; i < 3; i++) { res[i] = local_dir[i] * size[i]; } mju_normalize3(res); // transform to ellipsoid for (int i=0; i < 3; i++) { res[i] *= size[i]; } break; case mjGEOM_CYLINDER: // set result in XY plane: support on circle tmp = mju_sqrt(local_dir[0]*local_dir[0] + local_dir[1]*local_dir[1]); if (tmp > mjMINVAL) { res[0] = local_dir[0]/tmp*size[0]; res[1] = local_dir[1]/tmp*size[0]; } else { res[0] = res[1] = 0; } // set result in Z direction res[2] = mju_sign(local_dir[2]) * size[1]; break; case mjGEOM_BOX: for (int i=0; i < 3; i++) { res[i] = mju_sign(local_dir[i]) * size[i]; } break; case mjGEOM_MESH: case mjGEOM_SDF: // init search vertdata = m->mesh_vert + 3*m->mesh_vertadr[m->geom_dataid[g]]; tmp = -1E+10; ibest = -1; // no graph data: exhaustive search if (m->mesh_graphadr[m->geom_dataid[g]] < 0) { // search all vertices, find best for (int i=0; i < m->mesh_vertnum[m->geom_dataid[g]]; i++) { // vdot = dot(vertex, dir) vdot = local_dir[0] * (mjtNum)vertdata[3*i] + local_dir[1] * (mjtNum)vertdata[3*i+1] + local_dir[2] * (mjtNum)vertdata[3*i+2]; // update best if (vdot > tmp) { tmp = vdot; ibest = i; } } // record best vertex index, in globalid format obj->meshindex = ibest; } // hill-climb using graph data else { // get info graphadr = m->mesh_graphadr[m->geom_dataid[g]]; numvert = m->mesh_graph[graphadr]; vert_edgeadr = m->mesh_graph + graphadr + 2; vert_globalid = m->mesh_graph + graphadr + 2 + numvert; edge_localid = m->mesh_graph + graphadr + 2 + 2*numvert; // init with first vertex in convex hull or warmstart ibest = obj->meshindex < 0 ? 0 : obj->meshindex; tmp = local_dir[0] * (mjtNum)vertdata[3*vert_globalid[ibest]+0] + local_dir[1] * (mjtNum)vertdata[3*vert_globalid[ibest]+1] + local_dir[2] * (mjtNum)vertdata[3*vert_globalid[ibest]+2]; // hill-climb until no change change = 1; while (change) { // look for improvement in ibest neighborhood change = 0; int i = vert_edgeadr[ibest]; while ((locid=edge_localid[i]) >= 0) { // vdot = dot(vertex, local_dir) vdot = local_dir[0] * (mjtNum)vertdata[3*vert_globalid[locid]] + local_dir[1] * (mjtNum)vertdata[3*vert_globalid[locid]+1] + local_dir[2] * (mjtNum)vertdata[3*vert_globalid[locid]+2]; // update best if (vdot > tmp) { tmp = vdot; ibest = locid; change = 1; } // advance to next edge i++; } } // record best vertex index, in locid format obj->meshindex = ibest; // map best index to globalid ibest = vert_globalid[ibest]; } // sanity check, SHOULD NOT OCCUR if (ibest < 0) { mju_warning("mesh_support could not find support vertex"); mju_zero3(res); } // copy best vertex else { for (int i=0; i < 3; i++) { res[i] = (mjtNum)vertdata[3*ibest + i]; } } break; default: mjERROR("ccd support function is undefined for geom type %d", m->geom_type[g]); } // add local_dir*margin/2 to result for (int i=0; i < 3; i++) { res[i] += local_dir[i] * obj->margin/2; } // rotate result to global frame mju_mulMatVec3(res, d->geom_xmat+9*g, res); // add geom position mju_addTo3(res, d->geom_xpos+3*g); } // libccd prism support function static void mjccd_prism_support(const void *obj, const ccd_vec3_t *dir, ccd_vec3_t *vec) { mjc_prism_support(vec->v, (mjCCDObj*) obj, dir->v); } // ------------------------------------------------------------------------------------------------ // initialize a CCD object void mjc_initCCDObj(mjCCDObj* obj, const mjModel* m, const mjData* d, int g, mjtNum margin) { obj->model = m; obj->data = d; obj->geom = g; obj->margin = margin; obj->center = mjc_center; obj->vertindex = -1; obj->meshindex = -1; obj->flex = -1; obj->elem = -1; obj->vert = -1; mju_zero4(obj->rotate); obj->rotate[0] = 1; if (g >= 0) { obj->geom_type = m->geom_type[g]; switch ((mjtGeom) obj->geom_type) { case mjGEOM_ELLIPSOID: obj->support = mjc_ellipsoidSupport; break; case mjGEOM_MESH: case mjGEOM_SDF: if (m->mesh_graphadr[m->geom_dataid[g]] < 0 || m->mesh_vertnum[m->geom_dataid[g]] < mjMESH_HILLCLIMB_MIN) { obj->support = mjc_meshSupport; } else { obj->support = mjc_hillclimbSupport; } break; case mjGEOM_SPHERE: obj->support = mjc_sphereSupport; break; case mjGEOM_CAPSULE: obj->support = mjc_capsuleSupport; break; case mjGEOM_CYLINDER: obj->support = mjc_cylinderSupport; break; case mjGEOM_BOX: obj->support = mjc_boxSupport; break; case mjGEOM_HFIELD: obj->center = mjc_prism_center; obj->support = mjc_prism_support; break; default: obj->support = NULL; break; } } else { obj->geom_type = mjGEOM_FLEX; obj->support = mjc_flexSupport; } } // set flex data for CCD object static void mjc_setCCDObjFlex(mjCCDObj* obj, int flex, int elem, int vert) { obj->flex = flex; obj->elem = elem; obj->vert = vert; } // initialize CCD structure static void mjc_initCCD(ccd_t* ccd, const mjModel* m) { CCD_INIT(ccd); ccd->mpr_tolerance = m->opt.ccd_tolerance; ccd->epa_tolerance = m->opt.ccd_tolerance; // use MPR tolerance for EPA ccd->max_iterations = m->opt.ccd_iterations; } // find convex-convex collision static int mjc_CCDIteration(const mjModel* m, const mjData* d, mjCCDObj* obj1, mjCCDObj* obj2, mjContact* con, int max_contacts, mjtNum margin) { if (!mjDISABLED(mjDSBL_NATIVECCD)) { mjCCDConfig config; mjCCDStatus status; // set config config.max_iterations = m->opt.ccd_iterations; config.tolerance = m->opt.ccd_tolerance; config.max_contacts = max_contacts; config.dist_cutoff = 0; // no geom distances needed config.context = (void*)d; config.alloc = ccd_allocate; config.free = ccd_free; mjtNum dist = mjc_ccd(&config, &status, obj1, obj2); if (dist < 0) { for (int i = 0; i < status.nx; i++) { mjContact* c = con++; c->dist = margin + dist; mju_sub3(c->frame, status.x1 + 3*i, status.x2 + 3*i); mju_normalize3(c->frame); c->pos[0] = 0.5 * (status.x1[0 + 3*i] + status.x2[0 + 3*i]); c->pos[1] = 0.5 * (status.x1[1 + 3*i] + status.x2[1 + 3*i]); c->pos[2] = 0.5 * (status.x1[2 + 3*i] + status.x2[2 + 3*i]); mju_zero3(c->frame+3); } return status.nx; } return 0; } // init libccd structure ccd_t ccd; mjc_initCCD(&ccd, m); ccd.first_dir = ccdFirstDirDefault; ccd.center1 = mjccd_center; ccd.center2 = mjccd_center; ccd.support1 = mjccd_support; ccd.support2 = mjccd_support; ccd_vec3_t dir, pos; ccd_real_t depth; // call MPR from libccd if (ccdMPRPenetration(obj1, obj2, &ccd, &depth, &dir, &pos) == 0) { // contact is found but normal is undefined if (ccdVec3Eq(&dir, ccd_vec3_origin)) { return 0; } // fill in contact data con->dist = margin-depth; mju_copy3(con->frame, dir.v); mju_copy3(con->pos, pos.v); mju_zero3(con->frame+3); // both geoms: fix contact frame normal if (obj1->geom >= 0 && obj2->geom >= 0) { mjc_fixNormal(m, d, con, obj1->geom, obj2->geom); } return 1; } return 0; } // compare new contact to previous contacts, return 1 if it is far from all of them static int mjc_isDistinctContact(mjContact* con, int ncon, mjtNum tolerance) { for (int i=0; i < ncon-1; i++) { if (mju_dist3(con[i].pos, con[ncon - 1].pos) <= tolerance) { return 0; } } return 1; } // in-place rotation of spatial frame around given point of origin static void mju_rotateFrame(const mjtNum origin[3], const mjtNum rot[9], mjtNum xmat[9], mjtNum xpos[3]) { mjtNum mat[9], vec[3], rel[3]; // rotate frame: xmat = rot*xmat mju_mulMatMat3(mat, rot, xmat); mju_copy(xmat, mat, 9); // vector to rotation origin: rel = origin - xpos mju_sub3(rel, origin, xpos); // displacement of origin due to rotation: vec = rot*rel - rel mju_mulMatVec3(vec, rot, rel); mju_subFrom3(vec, rel); // correct xpos by subtracting displacement: xpos = xpos - vec mju_subFrom3(xpos, vec); } // return number of contacts supported by a single pass of narrowphase static int maxContacts(const mjCCDObj* obj1, const mjCCDObj* obj2) { const mjModel* m = obj1->model; // single pass not supported for margins if (obj1->margin > 0 || obj2->margin > 0) { return 1; } // can return 8 contacts for box-box collision in one pass int type1 = m->geom_type[obj1->geom]; int type2 = m->geom_type[obj2->geom]; if (type1 == mjGEOM_BOX && type2 == mjGEOM_BOX) { return 8; } // reduce mesh collisions to 4 contacts max if (type1 == mjGEOM_BOX || type1 == mjGEOM_MESH) { if (type2 == mjGEOM_BOX || type2 == mjGEOM_MESH) { return mjENABLED(mjENBL_MULTICCD) ? 4 : 1; } } // not supported for other geom types return 1; } // multi-point convex-convex collision, using libccd int mjc_Convex(const mjModel* m, const mjData* d, mjContact* con, int g1, int g2, mjtNum margin) { // init ccd objects mjCCDObj obj1, obj2; mjc_initCCDObj(&obj1, m, d, g1, margin); mjc_initCCDObj(&obj2, m, d, g2, margin); int max_contacts = maxContacts(&obj1, &obj2); // find initial contact int ncon = mjc_CCDIteration(m, d, &obj1, &obj2, con, max_contacts, margin); // no additional contacts needed if (!mjDISABLED(mjDSBL_NATIVECCD) && max_contacts > 1) { return ncon; } // look for additional contacts if (ncon == 1 && mjENABLED(mjENBL_MULTICCD) // TODO(tassa) leave as bitflag or make geom attribute (?) && m->geom_type[g1] != mjGEOM_ELLIPSOID && m->geom_type[g1] != mjGEOM_SPHERE && m->geom_type[g2] != mjGEOM_ELLIPSOID && m->geom_type[g2] != mjGEOM_SPHERE) { // multiCCD parameters const mjtNum relative_tolerance = 1e-3; const mjtNum perturbation_angle = 1e-3; // save positions and orientations of g1 and g2 mjtNum xpos1[3], xmat1[9], xpos2[3], xmat2[9]; mju_copy3(xpos1, d->geom_xpos+3*g1); mju_copy(xmat1, d->geom_xmat+9*g1, 9); mju_copy3(xpos2, d->geom_xpos+3*g2); mju_copy(xmat2, d->geom_xmat+9*g2, 9); // complete frame of initial contact mjtNum frame[9]; mju_copy(frame, con[0].frame, 9); mju_makeFrame(frame); // tolerance for determining if newly found contacts are distinct const mjtNum tolerance = relative_tolerance * mju_min(m->geom_rbound[g1], m->geom_rbound[g2]); // axes and rotation angles for perturbation test mjtNum* axes[2] = {frame+3, frame+6}; mjtNum angles[2] = {-perturbation_angle, perturbation_angle}; // rotate both geoms, search for new contacts for (int axis_id = 0; axis_id < 2; ++axis_id) { for (int angle_id = 0; angle_id < 2; ++angle_id) { mjtNum* axis = axes[axis_id]; mjtNum angle = angles[angle_id]; // make rotation matrix rot mjtNum quat[4], rot[9]; mju_axisAngle2Quat(quat, axis, angle); mju_quat2Mat(rot, quat); // rotate g1 around initial contact point mju_rotateFrame(con[0].pos, rot, d->geom_xmat+9*g1, d->geom_xpos+3*g1); // inversely rotate g2 around initial contact point mjtNum invrot[9]; mju_transpose(invrot, rot, 3, 3); mju_rotateFrame(con[0].pos, invrot, d->geom_xmat+9*g2, d->geom_xpos+3*g2); // search for new contact int new_contact = mjc_CCDIteration(m, d, &obj1, &obj2, con+ncon, 1, margin); // check new contact if (new_contact && mjc_isDistinctContact(con, ncon + 1, tolerance)) { // set penetration of new point to equal that of initial point con[ncon].dist = con[0].dist; // add new point ncon += 1; } // reset positions and orientations of g1 and g2 mju_copy3(d->geom_xpos+3*g1, xpos1); mju_copy(d->geom_xmat+9*g1, xmat1, 9); mju_copy3(d->geom_xpos+3*g2, xpos2); mju_copy(d->geom_xmat+9*g2, xmat2, 9); } } } return ncon; } // parameters for plane-mesh extra contacts const int maxplanemesh = 3; const mjtNum tolplanemesh = 0.3; // add one plane-mesh contact static int addplanemesh(mjContact* con, const float vertex[3], const mjtNum pos1[3], const mjtNum normal1[3], const mjtNum pos2[3], const mjtNum mat2[9], const mjtNum first[3], mjtNum rbound) { // compute point in global coordinates mjtNum pnt[3], v[3] = {vertex[0], vertex[1], vertex[2]}; mju_mulMatVec3(pnt, mat2, v); mju_addTo3(pnt, pos2); // skip if too close to first contact if (mju_dist3(pnt, first) < tolplanemesh*rbound) { return 0; } // pnt-pos difference vector mjtNum dif[3]; mju_sub3(dif, pnt, pos1); // set distance con->dist = mju_dot3(normal1, dif); // set position mju_copy3(con->pos, pnt); mju_addToScl3(con->pos, normal1, -0.5*con->dist); // set frame mju_copy3(con->frame, normal1); mju_zero3(con->frame+3); return 1; } // plane-convex collision, using libccd int mjc_PlaneConvex(const mjModel* m, const mjData* d, mjContact* con, int g1, int g2, mjtNum margin) { mjGETINFO mjtNum dist, dif[3], normal[3] = {mat1[2], mat1[5], mat1[8]}; ccd_vec3_t dir, vec; mjCCDObj obj; mjc_initCCDObj(&obj, m, d, g2, 0); // get support point in -normal direction ccdVec3Set(&dir, -mat1[2], -mat1[5], -mat1[8]); mjccd_support(&obj, &dir, &vec); // compute normal distance, return if too far mju_sub3(dif, vec.v, pos1); dist = mju_dot3(normal, dif); if (dist > margin) { return 0; } // fill in contact data con->dist = dist; mju_copy3(con->pos, vec.v); mju_addToScl3(con->pos, normal, -0.5*dist); mju_copy3(con->frame, normal); mju_zero3(con->frame+3); //--------------- add all/connected vertices below margin float* vertdata; int graphadr, numvert, locid; int *vert_edgeadr, *vert_globalid, *edge_localid; mjtNum vdot; int count = 1, g = g2; // g is an ellipsoid: no need for further mesh-specific processing if (m->geom_dataid[g] == -1) { return count; } // init vertdata = m->mesh_vert + 3*m->mesh_vertadr[m->geom_dataid[g]]; // express dir in geom local frame mjtNum locdir[3]; mju_mulMatTVec3(locdir, d->geom_xmat+9*g, dir.v); // inclusion threshold along locdir, relative to geom2 center mju_sub3(dif, pos2, pos1); mjtNum threshold = mju_dot3(normal, dif) - margin; // no graph data: exhaustive search if (m->mesh_graphadr[m->geom_dataid[g]] < 0) { // search all vertices, find best for (int i=0; i < m->mesh_vertnum[m->geom_dataid[g]] && count < maxplanemesh; i++) { // vdot = dot(vertex, dir) vdot = locdir[0] * (mjtNum)vertdata[3*i] + locdir[1] * (mjtNum)vertdata[3*i+1] + locdir[2] * (mjtNum)vertdata[3*i+2]; // detect contact, skip best if (vdot > threshold && i != obj.meshindex) { count += addplanemesh(con+count, vertdata+3*i, pos1, normal, pos2, mat2, con->pos, m->geom_rbound[g2]); } } } // use graph data else if (obj.meshindex >= 0) { // get info graphadr = m->mesh_graphadr[m->geom_dataid[g]]; numvert = m->mesh_graph[graphadr]; vert_edgeadr = m->mesh_graph + graphadr + 2; vert_globalid = m->mesh_graph + graphadr + 2 + numvert; edge_localid = m->mesh_graph + graphadr + 2 + 2*numvert; // look for contacts in ibest neighborhood int i = vert_edgeadr[obj.meshindex]; while ((locid=edge_localid[i]) >= 0 && count < maxplanemesh) { // vdot = dot(vertex, dir) vdot = locdir[0] * (mjtNum)vertdata[3*vert_globalid[locid]] + locdir[1] * (mjtNum)vertdata[3*vert_globalid[locid]+1] + locdir[2] * (mjtNum)vertdata[3*vert_globalid[locid]+2]; // detect contact if (vdot > threshold) { count += addplanemesh(con+count, vertdata+3*vert_globalid[locid], pos1, normal, pos2, mat2, con->pos, m->geom_rbound[g2]); } // advance to next edge i++; } } return count; } //---------------------------- heightfield collisions --------------------------------------------- // ccd prism first dir static void prism_firstdir(const void* o1, const void* o2, ccd_vec3_t *vec) { ccdVec3Set(vec, 0, 0, 1); } // add vertex to prism, count vertices static void addVert(int* nvert, mjCCDObj* obj, mjtNum x, mjtNum y, mjtNum z) { // move old data mju_copy3(obj->prism[0], obj->prism[1]); mju_copy3(obj->prism[1], obj->prism[2]); mju_copy3(obj->prism[3], obj->prism[4]); mju_copy3(obj->prism[4], obj->prism[5]); // add new vertex at last position obj->prism[2][0] = obj->prism[5][0] = x; obj->prism[2][1] = obj->prism[5][1] = y; obj->prism[5][2] = z; // count (*nvert)++; } // entry point for heightfield collisions int mjc_ConvexHField(const mjModel* m, const mjData* d, mjContact* con, int g1, int g2, mjtNum margin) { mjGETINFO_HFIELD mjtNum mat[9], savemat2[9], savepos2[3], pos[3], vec[3], r2, dx, dy; mjtNum xmin, xmax, ymin, ymax, zmin, zmax; int hid = m->geom_dataid[g1]; int nrow = m->hfield_nrow[hid]; int ncol = m->hfield_ncol[hid]; int dr[2], cnt, rmin, rmax, cmin, cmax; const float* data = m->hfield_data + m->hfield_adr[hid]; // ccd-related mjCCDObj obj1, obj2; mjc_initCCDObj(&obj1, m, d, g1, 0); mjc_initCCDObj(&obj2, m, d, g2, 0); ccd_vec3_t dirccd, vecccd; ccd_real_t depth; ccd_t ccd; // point size1 to hfield size instead of geom1 size size1 = m->hfield_size + 4*hid; //------------------------------------- frame alignment, box-sphere test // express geom2 pos in heightfield frame mju_sub3(vec, pos2, pos1); mju_mulMatTVec(pos, mat1, vec, 3, 3); // get geom2 rbound r2 = m->geom_rbound[g2]; // box-sphere test: horizontal plane for (int i=0; i < 2; i++) { if ((size1[i] < pos[i]-r2-margin) || (-size1[i] > pos[i]+r2+margin)) { return 0; } } // box-sphere test in: vertical direction if (size1[2] < pos[2]-r2-margin) { // up return 0; } if (-size1[3] > pos[2]+r2+margin) { // down return 0; } // express geom2 mat in heightfield frame mju_mulMatTMat3(mat, mat1, mat2); //------------------------------------- AABB computation, box-box test // save mat2 and pos2, replace with relative frame mju_copy(savemat2, mat2, 9); mju_copy3(savepos2, pos2); mju_copy(mat2, mat, 9); mju_copy3(pos2, pos); // get support point in +X ccdVec3Set(&dirccd, 1, 0, 0); mjccd_support(&obj2, &dirccd, &vecccd); xmax = vecccd.v[0]; // get support point in -X ccdVec3Set(&dirccd, -1, 0, 0); mjccd_support(&obj2, &dirccd, &vecccd); xmin = vecccd.v[0]; // get support point in +Y ccdVec3Set(&dirccd, 0, 1, 0); mjccd_support(&obj2, &dirccd, &vecccd); ymax = vecccd.v[1]; // get support point in -Y ccdVec3Set(&dirccd, 0, -1, 0); mjccd_support(&obj2, &dirccd, &vecccd); ymin = vecccd.v[1]; // get support point in +Z ccdVec3Set(&dirccd, 0, 0, 1); mjccd_support(&obj2, &dirccd, &vecccd); zmax = vecccd.v[2]; // get support point in -Z ccdVec3Set(&dirccd, 0, 0, -1); mjccd_support(&obj2, &dirccd, &vecccd); zmin = vecccd.v[2]; // box-box test if ((xmin-margin > size1[0]) || (xmax+margin < -size1[0]) || (ymin-margin > size1[1]) || (ymax+margin < -size1[1]) || (zmin-margin > size1[2]) || (zmax+margin < -size1[3])) { // restore mat2 and pos2 mju_copy(mat2, savemat2, 9); mju_copy3(pos2, savepos2); return 0; } // compute sub-grid bounds cmin = (int) mju_floor((xmin + size1[0]) / (2*size1[0]) * (ncol-1)); cmax = (int) mju_ceil ((xmax + size1[0]) / (2*size1[0]) * (ncol-1)); rmin = (int) mju_floor((ymin + size1[1]) / (2*size1[1]) * (nrow-1)); rmax = (int) mju_ceil ((ymax + size1[1]) / (2*size1[1]) * (nrow-1)); cmin = mjMAX(0, cmin); cmax = mjMIN(ncol-1, cmax); rmin = mjMAX(0, rmin); rmax = mjMIN(nrow-1, rmax); //------------------------------------- collision testing // init ccd structure mjc_initCCD(&ccd, m); ccd.first_dir = prism_firstdir; ccd.center1 = mjccd_prism_center; ccd.center2 = mjccd_center; ccd.support1 = mjccd_prism_support; ccd.support2 = mjccd_support; // geom margin needed for actual collision test obj2.margin = margin; // compute real-valued grid step, and triangulation direction dx = (2.0*size1[0]) / (ncol-1); dy = (2.0*size1[1]) / (nrow-1); dr[0] = 1; dr[1] = 0; // set zbottom value using base size obj1.prism[0][2] = obj1.prism[1][2] = obj1.prism[2][2] = -size1[3]; // process all prisms in sub-grid cnt = 0; for (int r=rmin; r < rmax; r++) { int nvert = 0; for (int c=cmin; c <= cmax; c++) { for (int i=0; i < 2; i++) { // send vertex to prism constructor addVert(&nvert, &obj1, dx*c-size1[0], dy*(r+dr[i])-size1[1], data[(r+dr[i])*ncol+c]*size1[2]+margin); // check for enough vertices if (nvert > 2) { // prism height test if (obj1.prism[3][2] < zmin && obj1.prism[4][2] < zmin && obj1.prism[5][2] < zmin) { continue; } // run penetration function, save contact if (mjc_penetration(m, &obj1, &obj2, &ccd, &depth, &dirccd, &vecccd) == 0 && !ccdVec3Eq(&dirccd, ccd_vec3_origin)) { // fill in contact data, transform to global coordinates con[cnt].dist = -depth; mju_mulMatVec3(con[cnt].frame, mat1, dirccd.v); mju_mulMatVec3(con[cnt].pos, mat1, vecccd.v); mju_addTo3(con[cnt].pos, pos1); mju_zero3(con[cnt].frame+3); // count, stop if max number reached cnt++; if (cnt >= mjMAXCONPAIR) { r = rmax+1; c = cmax+1; i = 3; break; } } } } } } // restore mat2 and pos2 mju_copy(mat2, savemat2, 9); mju_copy3(pos2, savepos2); // fix contact normals for (int i=0; i < cnt; i++) { mjc_fixNormal(m, d, con+i, g1, g2); } return cnt; } //--------------------------- fix contact frame normal --------------------------------------------- // compute normal for point outside ellipsoid, using ray-projection SQP static int mjc_ellipsoidInside(mjtNum nrm[3], const mjtNum pos[3], const mjtNum size[3]) { // algorithm constants const int maxiter = 30; const mjtNum tolerance = 1e-6; // precompute quantities mjtNum S2inv[3] = {1/(size[0]*size[0]), 1/(size[1]*size[1]), 1/(size[2]*size[2])}; mjtNum C = pos[0]*pos[0]*S2inv[0] + pos[1]*pos[1]*S2inv[1] + pos[2]*pos[2]*S2inv[2] - 1; if (C > 0) { return 0; } // normalize initial normal (just in case) mju_normalize3(nrm); // main iteration int iter; for (iter=0; iter < maxiter; iter++) { // coefficients and determinant of quadratic mjtNum A = nrm[0]*nrm[0]*S2inv[0] + nrm[1]*nrm[1]*S2inv[1] + nrm[2]*nrm[2]*S2inv[2]; mjtNum B = pos[0]*nrm[0]*S2inv[0] + pos[1]*nrm[1]*S2inv[1] + pos[2]*nrm[2]*S2inv[2]; mjtNum det = B*B - A*C; if (det < mjMINVAL || A < mjMINVAL) { return (iter > 0); } // ray intersection with ellipse: pos + x*nrm, x>=0 mjtNum x = (-B + mju_sqrt(det))/A; if (x < 0) { return (iter > 0); } // new point on ellipsoid mjtNum pnt[3]; mju_addScl3(pnt, pos, nrm, x); // normal at new point mjtNum newnrm[3] = {pnt[0]*S2inv[0], pnt[1]*S2inv[1], pnt[2]*S2inv[2]}; mju_normalize3(newnrm); // save change and assign mjtNum change = mju_dist3(nrm, newnrm); mju_copy3(nrm, newnrm); // terminate if converged if (change < tolerance) { break; } } return 1; } // compute normal for point inside ellipsoid, using diagonal QCQP static int mjc_ellipsoidOutside(mjtNum nrm[3], const mjtNum pos[3], const mjtNum size[3]) { // algorithm constants const int maxiter = 30; const mjtNum tolerance = 1e-6; // precompute quantities mjtNum S2[3] = {size[0]*size[0], size[1]*size[1], size[2]*size[2]}; mjtNum PS2[3] = {pos[0]*pos[0]*S2[0], pos[1]*pos[1]*S2[1], pos[2]*pos[2]*S2[2]}; // main iteration mjtNum la = 0; int iter; for (iter=0; iter < maxiter; iter++) { // precompute 1/(s^2+la) mjtNum R[3] = {1/(S2[0]+la), 1/(S2[1]+la), 1/(S2[2]+la)}; // value mjtNum val = PS2[0]*R[0]*R[0] + PS2[1]*R[1]*R[1] + PS2[2]*R[2]*R[2] - 1; if (val < tolerance) { break; } // derivative mjtNum deriv = -2*(PS2[0]*R[0]*R[0]*R[0] + PS2[1]*R[1]*R[1]*R[1] + PS2[2]*R[2]*R[2]*R[2]); if (deriv > -mjMINVAL) { break; } // delta mjtNum delta = -val/deriv; if (delta < tolerance) { break; } // update la += delta; } // compute normal given lambda nrm[0] = pos[0]/(S2[0]+la); nrm[1] = pos[1]/(S2[1]+la); nrm[2] = pos[2]/(S2[2]+la); mju_normalize3(nrm); return 1; } // entry point void mjc_fixNormal(const mjModel* m, const mjData* d, mjContact* con, int g1, int g2) { mjtNum dst1, dst2; // get geom ids and types int gid[2] = {g1, g2}; mjtGeom type[2]; for (int i=0; i < 2; i++) { type[i] = m->geom_type[gid[i]]; // set to mjGEOM_NONE if type cannot be processed if (type[i] != mjGEOM_SPHERE && type[i] != mjGEOM_CAPSULE && type[i] != mjGEOM_ELLIPSOID && type[i] != mjGEOM_CYLINDER) { type[i] = mjGEOM_NONE; } } // neither type can be processed: nothing to do if (type[0] == mjGEOM_NONE && type[1] == mjGEOM_NONE) { return; } // init normals mjtNum normal[2][3] = { {con->frame[0], con->frame[1], con->frame[2]}, {-con->frame[0], -con->frame[1], -con->frame[2]} }; // process geoms in type range int processed[2] = {0, 0}; for (int i=0; i < 2; i++) { if (type[i] != mjGEOM_NONE) { // get geom mat and size mjtNum* mat = d->geom_xmat + 9*gid[i]; mjtNum* size = m->geom_size + 3*gid[i]; // map contact point and normal to local frame mjtNum dif[3], pos[3], nrm[3]; mju_sub3(dif, con->pos, d->geom_xpos+3*gid[i]); mju_mulMatTVec3(pos, mat, dif); mju_mulMatTVec3(nrm, mat, normal[i]); // process according to type switch (type[i]) { case mjGEOM_SPHERE: mju_copy3(nrm, pos); processed[i] = 1; break; case mjGEOM_CAPSULE: // Z: bottom cap if (pos[2] < -size[1]) { nrm[2] = pos[2]+size[1]; } // Z: top cap else if (pos[2] > size[1]) { nrm[2] = pos[2]-size[1]; } // Z: cylinder else { nrm[2] = 0; } // copy XY nrm[0] = pos[0]; nrm[1] = pos[1]; processed[i] = 1; break; case mjGEOM_ELLIPSOID: // guard against invalid ellipsoid size (just in case) if (size[0] < mjMINVAL || size[1] < mjMINVAL || size[2] < mjMINVAL) { break; } // compute elliptic distance^2 dst1 = pos[0]*pos[0]/(size[0]*size[0]) + pos[1]*pos[1]/(size[1]*size[1]) + pos[2]*pos[2]/(size[2]*size[2]); // dispatch to inside or outside solver if (dst1 <= 1) { processed[i] = mjc_ellipsoidInside(nrm, pos, size); } else { processed[i] = mjc_ellipsoidOutside(nrm, pos, size); } break; case mjGEOM_CYLINDER: // skip if within 5% length of flat wall if (mju_abs(pos[2]) > 0.95*size[1]) { break; } // compute distances to flat and round wall dst1 = mju_abs(size[1]-mju_abs(pos[2])); dst2 = mju_abs(size[0]-mju_norm(pos, 2)); // require 4x closer to round than flat wall if (dst1 < 0.25*dst2) { break; } // set normal for round wall nrm[0] = pos[0]; nrm[1] = pos[1]; nrm[2] = 0; processed[i] = 1; break; default: // do nothing: only sphere, capsule, ellipsoid and cylinder are processed break; } // normalize and map normal to global frame if (processed[i]) { mju_normalize3(nrm); mju_mulMatVec3(normal[i], mat, nrm); } } } // both processed: average if (processed[0] && processed[1]) { mju_sub3(con->frame, normal[0], normal[1]); mju_normalize3(con->frame); } // first processed: copy else if (processed[0]) { mju_copy3(con->frame, normal[0]); } // second processed: copy reverse else if (processed[1]) { mju_scl3(con->frame, normal[1], -1); } // clear second frame axis if processed, just in case if (processed[0] || processed[1]) { mju_zero3(con->frame+3); } } //---------------------------- flex collisions --------------------------------------------- // geom-elem or elem-elem or vert-elem convex collision using ccd int mjc_ConvexElem(const mjModel* m, const mjData* d, mjContact* con, int g1, int f1, int e1, int v1, int f2, int e2, mjtNum margin) { mjCCDObj obj1, obj2; mjc_initCCDObj(&obj1, m, d, g1, margin); mjc_initCCDObj(&obj2, m, d, -1, margin); mjc_setCCDObjFlex(&obj1, f1, e1, v1); mjc_setCCDObjFlex(&obj2, f2, e2, -1); // find contacts return mjc_CCDIteration(m, d, &obj1, &obj2, con, 1, margin); } // test a height field and a flex element for collision int mjc_HFieldElem(const mjModel* m, const mjData* d, mjContact* con, int g, int f, int e, mjtNum margin) { mjtNum vec[3], dx, dy; mjtNum xmin, xmax, ymin, ymax, zmin, zmax; int dr[2], cnt, rmin, rmax, cmin, cmax; mjCCDObj obj1; obj1.center = mjc_prism_center; obj1.support = mjc_prism_support; // get hfield info int hid = m->geom_dataid[g]; int nrow = m->hfield_nrow[hid]; int ncol = m->hfield_ncol[hid]; mjtNum* hpos = d->geom_xpos + 3*g; mjtNum* hmat = d->geom_xmat + 9*g; mjtNum* hsize = m->hfield_size + 4*hid; const float* hdata = m->hfield_data + m->hfield_adr[hid]; // get elem indo int dim = m->flex_dim[f]; const int* edata = m->flex_elem + m->flex_elemdataadr[f] + e*(dim+1); mjtNum* evert[4] = {NULL, NULL, NULL, NULL}; for (int i=0; i <= dim; i++) { evert[i] = d->flexvert_xpos + 3*(m->flex_vertadr[f] + edata[i]); } mjtNum* ecenter = d->flexelem_aabb + 6*(m->flex_elemadr[f]+e); // ccd-related ccd_vec3_t dirccd, vecccd; ccd_real_t depth; mjCCDObj obj2; mjc_initCCDObj(&obj2, m, d, -1, margin); mjc_setCCDObjFlex(&obj2, f, e, -1); ccd_t ccd; //------------------------------------- AABB computation, box-box test // save elem vertices, transform to hfield frame mjtNum savevert[4][3]; for (int i=0; i <= dim; i++) { mju_copy3(savevert[i], evert[i]); mju_sub3(vec, evert[i], hpos); mju_mulMatTVec(evert[i], hmat, vec, 3, 3); } // save elem center, transform to hfield frame mjtNum savecenter[3]; mju_copy3(savecenter, ecenter); mju_sub3(vec, ecenter, hpos); mju_mulMatTVec(ecenter, hmat, vec, 3, 3); // compute elem bounding box (in hfield frame) xmin = xmax = evert[0][0]; ymin = ymax = evert[0][1]; zmin = zmax = evert[0][2]; for (int i=1; i <= dim; i++) { xmin = mju_min(xmin, evert[i][0]); xmax = mju_max(xmax, evert[i][0]); ymin = mju_min(ymin, evert[i][1]); ymax = mju_max(ymax, evert[i][1]); zmin = mju_min(zmin, evert[i][2]); zmax = mju_max(zmax, evert[i][2]); } // box-box test if ((xmin-margin > hsize[0]) || (xmax+margin < -hsize[0]) || (ymin-margin > hsize[1]) || (ymax+margin < -hsize[1]) || (zmin-margin > hsize[2]) || (zmax+margin < -hsize[3])) { // restore vertices and center for (int i=0; i <= dim; i++) { mju_copy3(evert[i], savevert[i]); } mju_copy3(ecenter, savecenter); return 0; } // compute sub-grid bounds cmin = (int) mju_floor((xmin + hsize[0]) / (2*hsize[0]) * (ncol-1)); cmax = (int) mju_ceil ((xmax + hsize[0]) / (2*hsize[0]) * (ncol-1)); rmin = (int) mju_floor((ymin + hsize[1]) / (2*hsize[1]) * (nrow-1)); rmax = (int) mju_ceil ((ymax + hsize[1]) / (2*hsize[1]) * (nrow-1)); cmin = mjMAX(0, cmin); cmax = mjMIN(ncol-1, cmax); rmin = mjMAX(0, rmin); rmax = mjMIN(nrow-1, rmax); //------------------------------------- collision testing // init ccd structure CCD_INIT(&ccd); ccd.first_dir = prism_firstdir; ccd.center1 = mjccd_prism_center; ccd.center2 = mjccd_center; ccd.support1 = mjccd_prism_support; ccd.support2 = mjccd_support; // set ccd parameters ccd.max_iterations = m->opt.ccd_iterations; ccd.mpr_tolerance = m->opt.ccd_tolerance; // compute real-valued grid step, and triangulation direction dx = (2.0*hsize[0]) / (ncol-1); dy = (2.0*hsize[1]) / (nrow-1); dr[0] = 1; dr[1] = 0; // set zbottom value using base size obj1.prism[0][2] = obj1.prism[1][2] = obj1.prism[2][2] = -hsize[3]; // process all prisms in sub-grid cnt = 0; for (int r=rmin; r < rmax; r++) { int nvert = 0; for (int c=cmin; c <= cmax; c++) { for (int k=0; k < 2; k++) { // send vertex to prism constructor addVert(&nvert, &obj1, dx*c-hsize[0], dy*(r+dr[k])-hsize[1], hdata[(r+dr[k])*ncol+c]*hsize[2]+margin); // check for enough vertices if (nvert > 2) { // prism height test if (obj1.prism[3][2] < zmin && obj1.prism[4][2] < zmin && obj1.prism[5][2] < zmin) { continue; } // run MPR, save contact if (mjc_penetration(m, &obj1, &obj2, &ccd, &depth, &dirccd, &vecccd) == 0) { if (!ccdVec3Eq(&dirccd, ccd_vec3_origin)) { // fill in contact data, transform to global coordinates con[cnt].dist = -depth; mju_mulMatVec3(con[cnt].frame, hmat, dirccd.v); mju_mulMatVec3(con[cnt].pos, hmat, vecccd.v); mju_addTo3(con[cnt].pos, hpos); mju_zero3(con[cnt].frame+3); // count, stop if max number reached cnt++; if (cnt >= mjMAXCONPAIR) { r = rmax+1; c = cmax+1; k = 3; break; } } } } } } } // restore elem vertices and center for (int i=0; i <= dim; i++) { mju_copy3(evert[i], savevert[i]); } mju_copy3(ecenter, savecenter); return cnt; }