opegles achieve 2d terrain destruction

Hello everyone!
I want to achieve a similar "Bouncing Church" Some effects of terrain destruction, I am using opengl es1.1, I used during this period numerous integration, mask, masks, pixel logic operations, to no avail including experimented glTexSubImage, but also unable to achieve the desired effect, only in the solid figure achieved, but the color chart can not be achieved, the request experts to give us, thank you!
Reply:
It seems that the world is really very cold, even a technology are reluctant to share their own solution!