Transforms - iOS Core Animation - page 93

//add cube face 5
transform = CATransform3DMakeTranslation (- 100 , 0 , 0 );
transform = CATransform3DRotate (transform, - M_PI_2 , 0 , 1 , 0 );
[ self addFace : 4 withTransform :transform];
//add cube face 6
transform = CATransform3DMakeTranslation ( 0 , 0 , - 100 );
transform = CATransform3DRotate (transform, M_PI , 0 , 1 , 0 );
[ self addFace : 5 withTransform :transform];
}
@end
Figure 5.20 The cube, displayed face-on
Our cube isn't really that impressive from this angle; it just looks like a square. To
appreciate it properly, we need to look at it from a different point of view.
Rotating the cube itself would be cumbersome because we'd have to rotate each face
individually. A simpler option is to rotate the camera , which we can do by adjusting the
sublayerTransform of our container view.
Add the following lines to rotate the perspective transform matrix before applying it to
the containerView layer:
perspective = CATransform3DRotate (perspective, - M_PI_4 , 1 , 0 , 0 );
perspective = CATransform3DRotate (perspective, - M_PI_4 , 0 , 1 , 0 );