Sample Code - 3D: Ray-Triangle Intersection

[c++] 3D: Ray-Triangle Intersection
bool IntersectTriangle(const D3DXVECTOR3& RayOrigin, const D3DXVECTOR3& RayDirection,
	D3DXVECTOR3& v0, D3DXVECTOR3& v1, D3DXVECTOR3& v2, float& t, float& u, float& v)

{
	D3DXVECTOR3 edge1 = v1 - v0;
	D3DXVECTOR3 edge2 = v2 - v0;

	D3DXVECTOR3 pvec;
	D3DXVec3Cross(&pvec, &RayDirection, &edge2);

	FLOAT det = D3DXVec3Dot(&edge1, &pvec);

	D3DXVECTOR3 tvec;
	if (det > 0) tvec = RayOrigin - v0;
	else {
		tvec = v0 - RayOrigin;
		det = -det;
	}

	if (det < 0.0001f) return false;

	u = D3DXVec3Dot(&tvec, &pvec);
	if (u < 0.0f || u > det) return false;

	D3DXVECTOR3 qvec;
	D3DXVec3Cross(&qvec, &tvec, &edge1);

	v = D3DXVec3Dot(&RayDirection, &qvec);
	if (v < 0.0f || u + v > det) return false;

	t = D3DXVec3Dot(&edge2, &qvec);
	FLOAT fInvDet = 1.0f / det;
	t *= fInvDet;
	u *= fInvDet;
	v *= fInvDet;

	return true;
}