Transformation for twisting a UIView on iPhone

Is there a wa开发者_运维问答y to use CATransform3D, or similar, to twist a UIView? What I mean is to rotate the top edge of the view, but keep the bottom edge where it is. All the transformations I've looked at keep the view 'flat'. Is this more of an Open GL task?

You need OpenGL. Here is a great tutorial from Jeff LaMarche to get your started: http://iphonedevelopment.blogspot.com/2009/06/opengl-es-from-ground-up-part-7_04.html