/// <summary>
/// Compute the difference between two frames and return the result as a new frame from the point of view of the first.
/// </summary>
/// <param name="b1">The base frame.</param>
/// <param name="b2">The frame to subtract from the base frame.</param>
/// <param name="output">Returns the difference between the two frames in the form of a third frame.</param>
public static void Subtract(ref Frame b1, ref Frame b2, out Frame output)
{
// apply inverse of b2's rotation to b1
Matrix m1, m2, rel;
b1.ToMatrix(out m1);
b2.ToMatrix(out m2);
Matrix.Transpose(ref m2, out m2);
Matrix.Multiply(ref m1, ref m2, out rel);
output.X = new Vector3(rel.M11, rel.M12, rel.M13);
output.Y = new Vector3(rel.M21, rel.M22, rel.M23);
output.Z = new Vector3(rel.M31, rel.M32, rel.M33);
// subtract b2's position from b1
Vector3.Subtract(ref b1.Origin, ref b2.Origin, out output.Origin);
}
/// <summary>
/// Compute the difference between two frames and return the result as a new frame from the point of view of the first.
/// </summary>
/// <param name="b1">The base frame.</param>
/// <param name="b2">The frame to subtract from the base frame.</param>
/// <param name="output">Returns the difference between the two frames in the form of a third frame.</param>
public static void Subtract(ref Frame b1, ref Frame b2, out Frame output)
{
// apply inverse of b2's rotation to b1
Matrix m1, m2, rel;
b1.ToMatrix(out m1);
b2.ToMatrix(out m2);
Matrix.Transpose(ref m2, out m2);
Matrix.Multiply(ref m1, ref m2, out rel);
output.X = new Vector3(rel.M11, rel.M12, rel.M13);
output.Y = new Vector3(rel.M21, rel.M22, rel.M23);
output.Z = new Vector3(rel.M31, rel.M32, rel.M33);
// subtract b2's position from b1
Vector3.Subtract(ref b1.Origin, ref b2.Origin, out output.Origin);
}