This has been driving me crazy and I hope someone can push me in the right direction. I have two UIViews that represent the left and right sides of a book. I have successfully used CATransform3DMakeRotation to rotate one UIView so that it flips up 90 degrees so that it just becomes a line. Now I want to start the other UIView in the "flipped-up" 90 degrees position and use CATransform3DMakeRotation to rotate it back down. I'm curious how to get the view in the 90 degree position to start? Do I need to animate it and set it with a duration of 0 or something like that? Any advice would be greatly appreciated. Thanks!