Ray Triangle Intersect Java

/**
	 * Precision collision detection between a ray and a triangle.
	 * @param origin - origin of the picking ray
	 * @param far_point - far collision of the picking ray
	 * @param point_a - the triangle's vertex0
	 * @param point_b - the triangle's vertex1
	 * @param point_c - the triangle's vertex2
	 * @return - the location of the intersection, as Vector3, else null for no collision
	 */
	public static Vector3 rayTriangleIntersect(Vector3 origin, Vector3 far_point, Vector3 point_a, Vector3 point_b, Vector3 point_c)
	{
		Vector3 normal, point_intersect, test_vector;

		//find the triangles normal
		normal = (point_b.subtract(point_a).normalize().crossProduct((point_c.subtract(point_a).normalize())));

		//find the distance from origin to the triangle
		float dist1 = (origin.subtract(point_a).dotProduct(normal));

		//find the distance from far_point to the triangle
		float dist2 = (far_point.subtract(point_a).dotProduct(normal));

		//check to see if the ray intersects the triangle
		if((dist1 * dist2) >= 0.0f) return null;//it doesn't

		//check if the line and plane are parallel
		if(dist1 == dist2) return null;//they are

		//find the point of intersection
		point_intersect = origin.add((far_point.subtract(origin)).multiply((-dist1 / (dist2 - dist1))));

		//test the point against all the edges of the triangle
		test_vector = normal.crossProduct((point_b.subtract(point_a)));
		if(test_vector.dotProduct(point_intersect.subtract(point_b)) < 0.0f)
			return null;//not inside face

		test_vector = normal.crossProduct((point_c.subtract(point_b)));
		if(test_vector.dotProduct(point_intersect.subtract(point_c)) < 0.0f)
			return null;//not inside face

		test_vector = normal.crossProduct((point_a.subtract(point_c)));
		if(test_vector.dotProduct(point_intersect.subtract(point_a)) < 0.0f)
			return null;//not inside face

		//the point is inside the face
		return point_intersect;
	}