Create CMAttitude rotation matrix from roll, pitch and yaw values

Question

I'm trying to get an (Apple style, CMAttitude) rotation matrix out of roll, pitch and yaw values. Does someone know how that conversion works?

Example:

roll: 1.01315, pitch: 1.54177 and yaw: -0.361097

should result in this rotation matrix:

Thanks!

Answer 1

I think you could achieve that with a CATransform3D.

You would use these two calls:

CATransform3D CATransform3DMakeRotation (CGFloat angle, CGFloat x, CGFloat y, CGFloat z);
CATransform3D CATransform3DRotate (CATransform3D t, CGFloat angle, CGFloat x, CGFloat y, CGFloat z)

You need to figure out how roll, pitch, and yaw correspond with your coordinate system (usually x, y, z, but could be z, x, y)

then just do a combo like this:

CATransform3D transform = CATransform3DMakeRotation(anglex, 1.0, 0.0, 0.0);
transform = CATransform3DRotate(transform, angley, 0.0, 1.0, 0.0);
transform = CATransform3DRotate(transform, anglez, 0.0, 0.0, 1.0);

your transform will now hold the matrix you are looking for.