bool
GfRay::Intersect(const GfPlane &plane,
double *distance, bool *frontFacing) const
{
// The dot product of the ray direction and the plane normal
// indicates the angle between them. Reject glancing
// intersections. Note: this also rejects ill-formed planes with
// zero normals.
double d = GfDot(_direction, plane.GetNormal());
if (d < GF_MIN_VECTOR_LENGTH && d > -GF_MIN_VECTOR_LENGTH)
return false;
// Get a point on the plane.
GfVec3d planePoint = plane.GetDistanceFromOrigin() * plane.GetNormal();
// Compute the parametric distance t to the plane. Reject
// intersections outside the ray bounds.
double t = GfDot(planePoint - _startPoint, plane.GetNormal()) / d;
if (t < 0.0)
return false;
if (distance)
*distance = t;
if (frontFacing)
*frontFacing = (d < 0.0);
return true;
}
bool
GfFrustum::Intersects(const GfBBox3d &bbox) const
{
if (bbox.GetBox().IsEmpty())
return false;
// Recalculate frustum planes if necessary
_CalculateFrustumPlanes();
// Get the bbox in its local space and the matrix that converts
// world space to that local space.
const GfRange3d &localBBox = bbox.GetRange();
const GfMatrix4d &worldToLocal = bbox.GetInverseMatrix();
// Test the bbox against each of the frustum planes, transforming
// the plane by the inverse of the matrix to bring it into the
// bbox's local space.
for (size_t i = 0; i < _planes.size(); i++) {
GfPlane localPlane = _planes[i];
localPlane.Transform(worldToLocal);
if (! localPlane.IntersectsPositiveHalfSpace(localBBox))
return false;
}
return true;
}
static string _Repr(GfPlane const &self) {
return TF_PY_REPR_PREFIX + "Plane(" + TfPyRepr(self.GetNormal()) + ", " +
TfPyRepr(self.GetDistanceFromOrigin()) + ")";
}
