# Ive never been able to understand this...

Okay, how can i make the corner of the wall touch the inner corner of the car, whilst still making the car bounce of the wall when it hits it head first. In theimage, the situation is that the car will bounce of the wall when it hits it head first, beacause the sphere covers that area, however, the corner of the wall cannot rreach the inner corner of car because of the sphere…how can i make it hit off a wall head first, and make the corner of the wall reach the iner corner of the car?

polytope is the convex shape made by the collision faces in your mesh

polyheder can be concave [it can have dents…] but is slower

okay thanks, but why does the sphere remain? shouldnt there be a dotted outline exactly like the object now?

yes, maybe it should be but not, the doted sphere means “dynamic object”… or at least I that means for me

yes, maybe it should be but not, the doted sphere means “dynamic object”… or at least I that means for me :P[/quote]

but that sphere also is the point where objects collide with the object the sphere is around…is there anywhere i can see a full description of teh game engine dynamic options?

Just make your sphere size smaller than the object with the bounds on, it should work perfectly now.

nope its not working.

Post the file than because I don’t know whats wrong

okay, here it is:

http://s32.yousendit.com/d.aspx?id=0AVI3XT6B8IN40O64BSP61E2HV

In what way is it not working? It seems fine to me.

Keith. 8)

it goes through the bottom box afterr stopping for a while

Turn bounds to polytope for the bottom block. Now when top block is polyheder it comes to rest just above the bottom block (because it doesn’t do concave shapes) and when its polytope it comes to rest on the bottom block normally.

Thats what you’re trying to achieve isn’t it?

Keith. 8)

okay, but what causes the slight gap between the two objects?

hey, i think this is what you want

httP://www.freewebs.com/demobobin/Physics.blend

omg thats it! how did you do it?

I just said polyheder doesn’t do concave shapes. The bottom of your top block has a concave shape in it so in polyheder the bounds are as if the bottom was flat. Pilytope mode takes care of this.

Keith. 8)