Apply collision event only on a specific mesh I've been using Blender Cycle render for over an year and never done any game engine... This morning I looked a tutorial how to make an object move and after that I wanted to experiment a bit. 

I did a simple project where I just move a ball in a box. The box is make of 2 meshes, a plain for the ground and a 4 sided cylinder(I don't know why I did't use a cube...) I setted those 2 meshes on static and the ball on dynamic.

But there is the problem. I put a collision sensor to make the ball bounce back with the proper rotation, but this event trigger even if the ball does not it the front wall. I understand that the ball is always colliding with the floor, but i would like to trigger this event only when hitting the wall when the up arrow is pressed.

Is there a way to trigger a collision event on the wall only?



Here
I found out by enabling the 'Invert' button, it's working like a key release event.


So I createdstrong text
another sensor keyboard event on up key
while Invert enabled linked to my 'Stop' logic block


and it works fine.