HOW TO Put decals on the position of the collision

Hi,

i'm doing a fps paintball game and i need put decals on the local of the collisions ( balls and objects) in spite of representing a splash. I
have no idea how can i do it :/
My world is an actor and my balls are body's. I have callbacks implemented and i know when the balls collide with the scenario, but i can't know the position of collision and the normal of the face. How can i do it?

Please help me.... i've any idea how can do it

PS. If anyone have a Demo, can send me??


Thanks