public static bool RayToRayDistance(Vector3 r1st, Vector3 r1dir, Vector3 r2st, Vector3 r2dir, out Vector3 closestPosOnR1, out float dist)
{
Vector3 ortho = r1dir % r2dir;
float a = ortho | r1st;
float b = ortho | r2st;
Vector3 ortho2 = ortho % r2dir;
ortho2.Normalize();
Plane pl = new Plane(ortho2, 0.0f);
pl.CalcDist(r2st);
float t;
if (!pl.RayPlaneIntersection(r1st, r1dir, out closestPosOnR1, out t)) {
dist = 0.0f;
return false;
}
dist = Math.Abs(a - b);
return true;
}