/************************************************************************* * * * Open Dynamics Engine, Copyright (C) 2001-2003 Russell L. Smith. * * All rights reserved. Email: russ@q12.org Web: www.q12.org * * * * This library is free software; you can redistribute it and/or * * modify it under the terms of EITHER: * * (1) The GNU Lesser General Public License as published by the Free * * Software Foundation; either version 2.1 of the License, or (at * * your option) any later version. The text of the GNU Lesser * * General Public License is included with this library in the * * file LICENSE.TXT. * * (2) The BSD-style license that is included with this library in * * the file LICENSE-BSD.TXT. * * * * This library is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files * * LICENSE.TXT and LICENSE-BSD.TXT for more details. * * * *************************************************************************/ /* standard ODE geometry primitives: public API and pairwise collision functions. the rule is that only the low level primitive collision functions should set dContactGeom::g1 and dContactGeom::g2. */ #include #include #include #include "config.h" #include "matrix.h" #include "odemath.h" #include "collision_kernel.h" #include "collision_std.h" #include "collision_util.h" #ifdef _MSC_VER #pragma warning(disable:4291) // for VC++, no complaints about "no matching operator delete found" #endif //**************************************************************************** // ray public API dxRay::dxRay (dSpaceID space, dReal _length) : dxGeom (space,1) { type = dRayClass; length = _length; } void dxRay::computeAABB() { dVector3 e; e[0] = final_posr->pos[0] + final_posr->R[0*4+2]*length; e[1] = final_posr->pos[1] + final_posr->R[1*4+2]*length; e[2] = final_posr->pos[2] + final_posr->R[2*4+2]*length; if (final_posr->pos[0] < e[0]){ aabb[0] = final_posr->pos[0]; aabb[1] = e[0]; } else{ aabb[0] = e[0]; aabb[1] = final_posr->pos[0]; } if (final_posr->pos[1] < e[1]){ aabb[2] = final_posr->pos[1]; aabb[3] = e[1]; } else{ aabb[2] = e[1]; aabb[3] = final_posr->pos[1]; } if (final_posr->pos[2] < e[2]){ aabb[4] = final_posr->pos[2]; aabb[5] = e[2]; } else{ aabb[4] = e[2]; aabb[5] = final_posr->pos[2]; } } dGeomID dCreateRay (dSpaceID space, dReal length) { return new dxRay (space,length); } void dGeomRaySetLength (dGeomID g, dReal length) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); dxRay *r = (dxRay*) g; r->length = length; dGeomMoved (g); } dReal dGeomRayGetLength (dGeomID g) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); dxRay *r = (dxRay*) g; return r->length; } void dGeomRaySet (dGeomID g, dReal px, dReal py, dReal pz, dReal dx, dReal dy, dReal dz) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); g->recomputePosr(); dReal* rot = g->final_posr->R; dReal* pos = g->final_posr->pos; dVector3 n; pos[0] = px; pos[1] = py; pos[2] = pz; n[0] = dx; n[1] = dy; n[2] = dz; dNormalize3(n); rot[0*4+2] = n[0]; rot[1*4+2] = n[1]; rot[2*4+2] = n[2]; dGeomMoved (g); } void dGeomRayGet (dGeomID g, dVector3 start, dVector3 dir) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); g->recomputePosr(); start[0] = g->final_posr->pos[0]; start[1] = g->final_posr->pos[1]; start[2] = g->final_posr->pos[2]; dir[0] = g->final_posr->R[0*4+2]; dir[1] = g->final_posr->R[1*4+2]; dir[2] = g->final_posr->R[2*4+2]; } void dGeomRaySetParams (dxGeom *g, int FirstContact, int BackfaceCull) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); dGeomRaySetFirstContact(g, FirstContact); dGeomRaySetBackfaceCull(g, BackfaceCull); } void dGeomRayGetParams (dxGeom *g, int *FirstContact, int *BackfaceCull) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); (*FirstContact) = ((g->gflags & RAY_FIRSTCONTACT) != 0); (*BackfaceCull) = ((g->gflags & RAY_BACKFACECULL) != 0); } // set/get backface culling flag void dGeomRaySetBackfaceCull (dxGeom *g, int backfaceCull) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); if (backfaceCull) { g->gflags |= RAY_BACKFACECULL; } else { g->gflags &= ~RAY_BACKFACECULL; } } int dGeomRayGetBackfaceCull (dxGeom *g) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); return ((g->gflags & RAY_BACKFACECULL) != 0); } // set/get first contact flag void dGeomRaySetFirstContact (dxGeom *g, int firstContact) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); if (firstContact) { g->gflags |= RAY_FIRSTCONTACT; } else { g->gflags &= ~RAY_FIRSTCONTACT; } } int dGeomRayGetFirstContact (dxGeom *g) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); return ((g->gflags & RAY_FIRSTCONTACT) != 0); } void dGeomRaySetClosestHit (dxGeom *g, int closestHit) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); if (closestHit){ g->gflags |= RAY_CLOSEST_HIT; } else g->gflags &= ~RAY_CLOSEST_HIT; } int dGeomRayGetClosestHit (dxGeom *g) { dUASSERT (g && g->type == dRayClass,"argument not a ray"); return ((g->gflags & RAY_CLOSEST_HIT) != 0); } // if mode==1 then use the sphere exit contact, not the entry contact static int ray_sphere_helper (dxRay *ray, dVector3 sphere_pos, dReal radius, dContactGeom *contact, int mode) { dVector3 q; q[0] = ray->final_posr->pos[0] - sphere_pos[0]; q[1] = ray->final_posr->pos[1] - sphere_pos[1]; q[2] = ray->final_posr->pos[2] - sphere_pos[2]; dReal B = dCalcVectorDot3_14(q,ray->final_posr->R+2); dReal C = dCalcVectorDot3(q,q) - radius*radius; // note: if C <= 0 then the start of the ray is inside the sphere dReal k = B*B - C; if (k < 0) return 0; k = dSqrt(k); dReal alpha; if (mode && C >= 0) { alpha = -B + k; if (alpha < 0) return 0; } else { alpha = -B - k; if (alpha < 0) { alpha = -B + k; if (alpha < 0) return 0; } } if (alpha > ray->length) return 0; contact->pos[0] = ray->final_posr->pos[0] + alpha*ray->final_posr->R[0*4+2]; contact->pos[1] = ray->final_posr->pos[1] + alpha*ray->final_posr->R[1*4+2]; contact->pos[2] = ray->final_posr->pos[2] + alpha*ray->final_posr->R[2*4+2]; dReal nsign = (C < 0 || mode) ? REAL(-1.0) : REAL(1.0); contact->normal[0] = nsign*(contact->pos[0] - sphere_pos[0]); contact->normal[1] = nsign*(contact->pos[1] - sphere_pos[1]); contact->normal[2] = nsign*(contact->pos[2] - sphere_pos[2]); dNormalize3 (contact->normal); contact->depth = alpha; return 1; } int dCollideRaySphere (dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip) { dIASSERT (skip >= (int)sizeof(dContactGeom)); dIASSERT (o1->type == dRayClass); dIASSERT (o2->type == dSphereClass); dIASSERT ((flags & NUMC_MASK) >= 1); dxRay *ray = (dxRay*) o1; dxSphere *sphere = (dxSphere*) o2; contact->g1 = ray; contact->g2 = sphere; contact->side1 = -1; contact->side2 = -1; return ray_sphere_helper (ray,sphere->final_posr->pos,sphere->radius,contact,0); } int dCollideRayBox (dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip) { dIASSERT (skip >= (int)sizeof(dContactGeom)); dIASSERT (o1->type == dRayClass); dIASSERT (o2->type == dBoxClass); dIASSERT ((flags & NUMC_MASK) >= 1); dxRay *ray = (dxRay*) o1; dxBox *box = (dxBox*) o2; contact->g1 = ray; contact->g2 = box; contact->side1 = -1; contact->side2 = -1; int i; // compute the start and delta of the ray relative to the box. // we will do all subsequent computations in this box-relative coordinate // system. we have to do a translation and rotation for each point. dVector3 tmp,s,v; tmp[0] = ray->final_posr->pos[0] - box->final_posr->pos[0]; tmp[1] = ray->final_posr->pos[1] - box->final_posr->pos[1]; tmp[2] = ray->final_posr->pos[2] - box->final_posr->pos[2]; dMultiply1_331 (s,box->final_posr->R,tmp); tmp[0] = ray->final_posr->R[0*4+2]; tmp[1] = ray->final_posr->R[1*4+2]; tmp[2] = ray->final_posr->R[2*4+2]; dMultiply1_331 (v,box->final_posr->R,tmp); // mirror the line so that v has all components >= 0 dVector3 sign; for (i=0; i<3; i++) { if (v[i] < 0) { s[i] = -s[i]; v[i] = -v[i]; sign[i] = 1; } else sign[i] = -1; } // compute the half-sides of the box dReal h[3]; h[0] = REAL(0.5) * box->side[0]; h[1] = REAL(0.5) * box->side[1]; h[2] = REAL(0.5) * box->side[2]; // do a few early exit tests if ((s[0] < -h[0] && v[0] <= 0) || s[0] > h[0] || (s[1] < -h[1] && v[1] <= 0) || s[1] > h[1] || (s[2] < -h[2] && v[2] <= 0) || s[2] > h[2] || (v[0] == 0 && v[1] == 0 && v[2] == 0)) { return 0; } // compute the t=[lo..hi] range for where s+v*t intersects the box dReal lo = -dInfinity; dReal hi = dInfinity; int nlo = 0, nhi = 0; for (i=0; i<3; i++) { if (v[i] != 0) { dReal k = (-h[i] - s[i])/v[i]; if (k > lo) { lo = k; nlo = i; } k = (h[i] - s[i])/v[i]; if (k < hi) { hi = k; nhi = i; } } } // check if the ray intersects if (lo > hi) return 0; dReal alpha; int n; if (lo >= 0) { alpha = lo; n = nlo; } else { alpha = hi; n = nhi; } if (alpha < 0 || alpha > ray->length) return 0; contact->pos[0] = ray->final_posr->pos[0] + alpha*ray->final_posr->R[0*4+2]; contact->pos[1] = ray->final_posr->pos[1] + alpha*ray->final_posr->R[1*4+2]; contact->pos[2] = ray->final_posr->pos[2] + alpha*ray->final_posr->R[2*4+2]; contact->normal[0] = box->final_posr->R[0*4+n] * sign[n]; contact->normal[1] = box->final_posr->R[1*4+n] * sign[n]; contact->normal[2] = box->final_posr->R[2*4+n] * sign[n]; contact->depth = alpha; return 1; } int dCollideRayCapsule (dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip) { dIASSERT (skip >= (int)sizeof(dContactGeom)); dIASSERT (o1->type == dRayClass); dIASSERT (o2->type == dCapsuleClass); dIASSERT ((flags & NUMC_MASK) >= 1); dxRay *ray = (dxRay*) o1; dxCapsule *ccyl = (dxCapsule*) o2; contact->g1 = ray; contact->g2 = ccyl; contact->side1 = -1; contact->side2 = -1; dReal lz2 = ccyl->lz * REAL(0.5); // compute some useful info dVector3 cs,q,r; dReal C,k; cs[0] = ray->final_posr->pos[0] - ccyl->final_posr->pos[0]; cs[1] = ray->final_posr->pos[1] - ccyl->final_posr->pos[1]; cs[2] = ray->final_posr->pos[2] - ccyl->final_posr->pos[2]; k = dCalcVectorDot3_41(ccyl->final_posr->R+2,cs); // position of ray start along ccyl axis q[0] = k*ccyl->final_posr->R[0*4+2] - cs[0]; q[1] = k*ccyl->final_posr->R[1*4+2] - cs[1]; q[2] = k*ccyl->final_posr->R[2*4+2] - cs[2]; C = dCalcVectorDot3(q,q) - ccyl->radius*ccyl->radius; // if C < 0 then ray start position within infinite extension of cylinder // see if ray start position is inside the capped cylinder int inside_ccyl = 0; if (C < 0) { if (k < -lz2) k = -lz2; else if (k > lz2) k = lz2; r[0] = ccyl->final_posr->pos[0] + k*ccyl->final_posr->R[0*4+2]; r[1] = ccyl->final_posr->pos[1] + k*ccyl->final_posr->R[1*4+2]; r[2] = ccyl->final_posr->pos[2] + k*ccyl->final_posr->R[2*4+2]; if ((ray->final_posr->pos[0]-r[0])*(ray->final_posr->pos[0]-r[0]) + (ray->final_posr->pos[1]-r[1])*(ray->final_posr->pos[1]-r[1]) + (ray->final_posr->pos[2]-r[2])*(ray->final_posr->pos[2]-r[2]) < ccyl->radius*ccyl->radius) { inside_ccyl = 1; } } // compute ray collision with infinite cylinder, except for the case where // the ray is outside the capped cylinder but within the infinite cylinder // (it that case the ray can only hit endcaps) if (!inside_ccyl && C < 0) { // set k to cap position to check if (k < 0) k = -lz2; else k = lz2; } else { dReal uv = dCalcVectorDot3_44(ccyl->final_posr->R+2,ray->final_posr->R+2); r[0] = uv*ccyl->final_posr->R[0*4+2] - ray->final_posr->R[0*4+2]; r[1] = uv*ccyl->final_posr->R[1*4+2] - ray->final_posr->R[1*4+2]; r[2] = uv*ccyl->final_posr->R[2*4+2] - ray->final_posr->R[2*4+2]; dReal A = dCalcVectorDot3(r,r); // A == 0 means that the ray and ccylinder axes are parallel if (A == 0) { // There is a division by A below... // set k to cap position to check if (uv < 0) k = -lz2; else k = lz2; } else { dReal B = 2*dCalcVectorDot3(q,r); k = B*B-4*A*C; if (k < 0) { // the ray does not intersect the infinite cylinder, but if the ray is // inside and parallel to the cylinder axis it may intersect the end // caps. set k to cap position to check. if (!inside_ccyl) return 0; if (uv < 0) k = -lz2; else k = lz2; } else { k = dSqrt(k); A = dRecip (2*A); dReal alpha = (-B-k)*A; if (alpha < 0) { alpha = (-B+k)*A; if (alpha < 0) return 0; } if (alpha > ray->length) return 0; // the ray intersects the infinite cylinder. check to see if the // intersection point is between the caps contact->pos[0] = ray->final_posr->pos[0] + alpha*ray->final_posr->R[0*4+2]; contact->pos[1] = ray->final_posr->pos[1] + alpha*ray->final_posr->R[1*4+2]; contact->pos[2] = ray->final_posr->pos[2] + alpha*ray->final_posr->R[2*4+2]; q[0] = contact->pos[0] - ccyl->final_posr->pos[0]; q[1] = contact->pos[1] - ccyl->final_posr->pos[1]; q[2] = contact->pos[2] - ccyl->final_posr->pos[2]; k = dCalcVectorDot3_14(q,ccyl->final_posr->R+2); dReal nsign = inside_ccyl ? REAL(-1.0) : REAL(1.0); if (k >= -lz2 && k <= lz2) { contact->normal[0] = nsign * (contact->pos[0] - (ccyl->final_posr->pos[0] + k*ccyl->final_posr->R[0*4+2])); contact->normal[1] = nsign * (contact->pos[1] - (ccyl->final_posr->pos[1] + k*ccyl->final_posr->R[1*4+2])); contact->normal[2] = nsign * (contact->pos[2] - (ccyl->final_posr->pos[2] + k*ccyl->final_posr->R[2*4+2])); dNormalize3 (contact->normal); contact->depth = alpha; return 1; } // the infinite cylinder intersection point is not between the caps. // set k to cap position to check. if (k < 0) k = -lz2; else k = lz2; } } } // check for ray intersection with the caps. k must indicate the cap // position to check q[0] = ccyl->final_posr->pos[0] + k*ccyl->final_posr->R[0*4+2]; q[1] = ccyl->final_posr->pos[1] + k*ccyl->final_posr->R[1*4+2]; q[2] = ccyl->final_posr->pos[2] + k*ccyl->final_posr->R[2*4+2]; return ray_sphere_helper (ray,q,ccyl->radius,contact, inside_ccyl); } int dCollideRayPlane (dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip) { dIASSERT (skip >= (int)sizeof(dContactGeom)); dIASSERT (o1->type == dRayClass); dIASSERT (o2->type == dPlaneClass); dIASSERT ((flags & NUMC_MASK) >= 1); dxRay *ray = (dxRay*) o1; dxPlane *plane = (dxPlane*) o2; dReal alpha = plane->p[3] - dCalcVectorDot3 (plane->p,ray->final_posr->pos); // note: if alpha > 0 the starting point is below the plane dReal nsign = (alpha > 0) ? REAL(-1.0) : REAL(1.0); dReal k = dCalcVectorDot3_14(plane->p,ray->final_posr->R+2); if (k==0) return 0; // ray parallel to plane alpha /= k; if (alpha < 0 || alpha > ray->length) return 0; contact->pos[0] = ray->final_posr->pos[0] + alpha*ray->final_posr->R[0*4+2]; contact->pos[1] = ray->final_posr->pos[1] + alpha*ray->final_posr->R[1*4+2]; contact->pos[2] = ray->final_posr->pos[2] + alpha*ray->final_posr->R[2*4+2]; contact->normal[0] = nsign*plane->p[0]; contact->normal[1] = nsign*plane->p[1]; contact->normal[2] = nsign*plane->p[2]; contact->depth = alpha; contact->g1 = ray; contact->g2 = plane; contact->side1 = -1; contact->side2 = -1; return 1; } // Ray-Cylinder collider by Joseph Cooper (2011) int dCollideRayCylinder( dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip ) { dIASSERT( skip >= (int)sizeof( dContactGeom ) ); dIASSERT( o1->type == dRayClass ); dIASSERT( o2->type == dCylinderClass ); dIASSERT( (flags & NUMC_MASK) >= 1 ); dxRay* ray = (dxRay*)( o1 ); dxCylinder* cyl = (dxCylinder*)( o2 ); // Fill in contact information. contact->g1 = ray; contact->g2 = cyl; contact->side1 = -1; contact->side2 = -1; const dReal half_length = cyl->lz * REAL( 0.5 ); /* Possible collision cases: * Ray origin between/outside caps * Ray origin within/outside radius * Ray direction left/right/perpendicular * Ray direction parallel/perpendicular/other * * Ray origin cases (ignoring origin on surface) * * A B * /-\-----------\ * C ( ) D ) * \_/___________/ * * Cases A and D can collide with caps or cylinder * Case C can only collide with the caps * Case B can only collide with the cylinder * Case D will produce inverted normals * If the ray is perpendicular, only check the cylinder * If the ray is parallel to cylinder axis, * we can only check caps * If the ray points right, * Case A,C Check left cap * Case D Check right cap * If the ray points left * Case A,C Check right cap * Case D Check left cap * Case B, check only first possible cylinder collision * Case D, check only second possible cylinder collision */ // Find the ray in the cylinder coordinate frame: dVector3 tmp; dVector3 pos; // Ray origin in cylinder frame dVector3 dir; // Ray direction in cylinder frame // Translate ray start by inverse cyl dSubtractVectors3(tmp,ray->final_posr->pos,cyl->final_posr->pos); // Rotate ray start by inverse cyl dMultiply1_331(pos,cyl->final_posr->R,tmp); // Get the ray's direction tmp[0] = ray->final_posr->R[2]; tmp[1] = ray->final_posr->R[6]; tmp[2] = ray->final_posr->R[10]; // Rotate the ray direction by inverse cyl dMultiply1_331(dir,cyl->final_posr->R,tmp); // Is the ray origin inside of the (extended) cylinder? dReal r2 = cyl->radius*cyl->radius; dReal C = pos[0]*pos[0] + pos[1]*pos[1] - r2; // Find the different cases // Is ray parallel to the cylinder length? int parallel = (dir[0]==0 && dir[1]==0); // Is ray perpendicular to the cylinder length? int perpendicular = (dir[2]==0); // Is ray origin within the radius of the caps? int inRadius = (C<=0); // Is ray origin between the top and bottom caps? int inCaps = (dFabs(pos[2])<=half_length); int checkCaps = (!perpendicular && (!inCaps || inRadius)); int checkCyl = (!parallel && (!inRadius || inCaps)); int flipNormals = (inCaps&&inRadius); dReal tt=-dInfinity; // Depth to intersection dVector3 tmpNorm = {dNaN, dNaN, dNaN}; // ensure we don't leak garbage if (checkCaps) { // Make it so we only need to check one cap int flipDir = 0; // Wish c had logical xor... if ((dir[2]<0 && flipNormals) || (dir[2]>0 && !flipNormals)) { flipDir = 1; dir[2]=-dir[2]; pos[2]=-pos[2]; } // The cap is half the cylinder's length // from the cylinder's origin // We only checkCaps if dir[2]!=0 tt = (half_length-pos[2])/dir[2]; if (tt>=0 && tt<=ray->length) { tmp[0] = pos[0] + tt*dir[0]; tmp[1] = pos[1] + tt*dir[1]; // Ensure collision point is within cap circle if (tmp[0]*tmp[0] + tmp[1]*tmp[1] <= r2) { // Successful collision tmp[2] = (flipDir)?-half_length:half_length; tmpNorm[0]=0; tmpNorm[1]=0; tmpNorm[2]=(flipDir!=flipNormals)?-REAL(1.0):REAL(1.0); checkCyl = 0; // Short circuit cylinder check } else { // Ray hits cap plane outside of cap circle tt=-dInfinity; // No collision yet } } else { // The cap plane is beyond (or behind) the ray length tt=-dInfinity; // No collision yet } if (flipDir) { // Flip back dir[2]=-dir[2]; pos[2]=-pos[2]; } } if (checkCyl) { // Compute quadratic formula for parametric ray equation dReal A = dir[0]*dir[0] + dir[1]*dir[1]; dReal B = 2*(pos[0]*dir[0] + pos[1]*dir[1]); // Already computed C dReal k = B*B - 4*A*C; // Check collision with infinite cylinder // k<0 means the ray passes outside the cylinder // k==0 means ray is tangent to cylinder (or parallel) // // Our quadratic formula: tt = (-B +- sqrt(k))/(2*A) // // A must be positive (otherwise we wouldn't be checking // cylinder because ray is parallel) // if (k<0) ray doesn't collide with sphere // if (B > sqrt(k)) then both times are negative // -- don't calculate // if (B<-sqrt(k)) then both times are positive (Case A or B) // -- only calculate first, if first isn't valid // -- second can't be without first going through a cap // otherwise (fabs(B)<=sqrt(k)) then C<=0 (ray-origin inside/on cylinder) // -- only calculate second collision if (k>=0 && (B<0 || B*B<=k)) { k = dSqrt(k); A = dRecip(2*A); if (dFabs(B)<=k) { tt = (-B + k)*A; // Second solution // If ray origin is on surface and pointed out, we // can get a tt=0 solution... } else { tt = (-B - k)*A; // First solution } if (tt<=ray->length) { tmp[2] = pos[2] + tt*dir[2]; if (dFabs(tmp[2])<=half_length) { // Valid solution tmp[0] = pos[0] + tt*dir[0]; tmp[1] = pos[1] + tt*dir[1]; tmpNorm[0] = tmp[0]/cyl->radius; tmpNorm[1] = tmp[1]/cyl->radius; tmpNorm[2] = 0; if (flipNormals) { // Ray origin was inside cylinder tmpNorm[0] = -tmpNorm[0]; tmpNorm[1] = -tmpNorm[1]; } } else { // Ray hits cylinder outside of caps tt=-dInfinity; } } else { // Ray doesn't reach the cylinder tt=-dInfinity; } } } if (tt>0) { contact->depth = tt; // Transform the point back to world coordinates tmpNorm[3]=0; tmp[3] = 0; dMultiply0_331(contact->normal,cyl->final_posr->R,tmpNorm); dMultiply0_331(contact->pos,cyl->final_posr->R,tmp); contact->pos[0]+=cyl->final_posr->pos[0]; contact->pos[1]+=cyl->final_posr->pos[1]; contact->pos[2]+=cyl->final_posr->pos[2]; return 1; } // No contact with anything. return 0; }