public static void Multiply(ref AffineTransform a, ref AffineTransform b, out AffineTransform transform)
{
Vector3 translation;
Matrix3x3.Transform(ref a.Translation, ref b.LinearTransform, out translation);
transform.Translation = b.Translation + translation;
Matrix3x3.Multiply(ref a.LinearTransform, ref b.LinearTransform, out transform.LinearTransform);
}