masking an image with a polygon

[dmurph]

I have an application where one image will gradually appear over another in a pie-slice style. This is meant to be a smooth transition.

I've explored a lot of posts with masking but I haven't really found a good starting point. Should I use the OpenGL framework like in the PaintGL demo? What direction should I go for achieving this result?

I'm just looking for pointers in the right direction, as I'm feeling a bit lost. Any example code or references are appreciated as well

[abhimanipal]

	[UIView beginAnimations:nil context:NULL];
	[UIView setAnimationDuration:1];
	[UIView setAnimationTransition:UIViewAnimationTransitionCurlUp forView:imageView cache:YES];
//	[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:imageView cache:YES];
	imageView.image=image;
	[UIView commitAnimations];

This is what happens. I have an imageView which is displaying an image. Aftet the user presses a button another image whose data I have store in UIImage *image replaces the current image. This transition is animated

[dmurph]

Thanks, but unfortunately there is no provided animation that i'm looking for. Picture an expanding pie slice. It's for a timer, where the second hand slowly reveals the image.

On that note, is there an easy way to make a custom animation? Would it be easy to copy one of those animations to do what I want to do?

[abhimanipal]

making custom animations is not easy if you do not have sufficient background in that are.... best of luck