Question

If you want to rotate an object using core animation, in radians, in the z axis, which of the following key paths of layer’s CATransform3D matrix will you use? (more than 1 options can be right).

1. rotation
2. rotation.xy
3. rotation.x
4. rotation.y
5. rotation.z

Answer 1

Not totally clear about the options you gave, but I use the code below to do rotation:

[[_yourView layer] setAnchorPoint:CGPointMake(0.0f, 0.5)];
[UIView animateWithDuration:1.0f
                      delay:0.0f
                    options:UIViewAnimationCurveEaseInOut
                 animations:^{
                     CATransform3D rotation = CATransform3DIdentity;
                     rotation.m34 = 1.0f / -300.0f;
                     rotation = CATransform3DRotate(rotation, -60.0f * M_PI / 180.0f, 0.0f, 1.0f, 0.0f);
                     [[_yourView layer] setTransform:rotation];
                 }
                 completion:nil];

It is rotated in y axis(so, the view will change in z direction), you can set the rotation for other axis by setting the params below:

rotation = CATransform3DRotate(rotation, -60.0f * M_PI / 180.0f, 0.0f, 1.0f, 0.0f);