public Triangle find(Vector3 p, Triangle start) {
		if (start == null)
			start = this.startTriangle;
		Triangle T = find(start, p);
		return T;
	}
public Triangle find ( Vector3 p , Triangle start ) { if ( start == null ) start = this . startTriangle ; Triangle T = find ( start , p ) ; return T ; }
finds the triangle the query point falls in, note if out-side of this
triangulation a half plane triangle will be returned (see contains). the
search starts from the the start triangle

@param p
query point
@param start
the triangle the search starts at.
@return the triangle that point p is in..