I'm learning to use the game engine and I don't know why a mesh change its shape when I press P key.
This happened when I subdivided the red mesh. I subdivided it because I want the ball collide the red wall but I don't want a rigid wall, I want a soft wall.
Here is the file: http://www.pasteall.org/blend/28811 (The ball moves with left and right arrows)
Thank you!