Function createTriangulatedSphere

tutorials/collide/collide_device.cpp:74–164

}

unsigned int createTriangulatedSphere (RTCScene scene, const Vec3fa& p, float r)
{
  /* create triangle mesh */
  std::unique_ptr<collide2::Mesh> sphere (new collide2::Mesh());
  sphere->x_.resize (numTheta*(numPhi-1)+2);
  sphere->tris_.resize (2*numTheta*(numPhi-1));

  /* create sphere */
  int tri = 0;
  const float rcpNumTheta = rcp((float)numTheta);
  const float rcpNumPhi   = rcp((float)numPhi);
  sphere->x_[0].x = p.x;
  sphere->x_[0].y = p.y + r;
  sphere->x_[0].z = p.z;

  for (int phi=0; phi<numPhi-1; phi++)
  {
    const float phif   = (phi+1)*float(pi)*rcpNumPhi;
    const float sinp   = sin(phif);
    const float cosp   = cos(phif);
    for (int theta=0; theta<numTheta; theta++)
    {
      const float thetaf = theta*2.0f*float(pi)*rcpNumTheta;

      auto& v = sphere->x_[phi*(numTheta)+theta+1];
      v.x = p.x + r*sinp*sin(thetaf);
      v.y = p.y + r*cosp;
      v.z = p.z + r*sinp*cos(thetaf);
    }
  }
  sphere->x_[numTheta*(numPhi-1)+1].x = p.x;
  sphere->x_[numTheta*(numPhi-1)+1].y = p.y - r;
  sphere->x_[numTheta*(numPhi-1)+1].z = p.z;

  for (int theta=0; theta<numTheta; theta++) {
    sphere->tris_[tri].v0 = theta+1;
    sphere->tris_[tri].v1 = 0;
    sphere->tris_[theta].v2 = (theta+1)%numTheta + 1;
    tri++;
  }

  for (int phi=0; phi<numPhi-2; phi++)
  {
    for (int theta=0; theta<numTheta; theta++)
    {
      int p00 = phi*numTheta + 1 + theta;
      int p01 = phi*numTheta + 1 + (theta+1)%numTheta;
      int p10 = (phi+1)*numTheta + 1 + theta;
      int p11 = (phi+1)*numTheta + 1 + (theta+1)%numTheta;

      sphere->tris_[tri].v0 = p10;
      sphere->tris_[tri].v1 = p01;
      sphere->tris_[tri].v2 = p00;
      tri++;

      sphere->tris_[tri].v0 = p11;
      sphere->tris_[tri].v1 = p01;
      sphere->tris_[tri].v2 = p10;