Too much force = through walls???

Game Engine Game Engine Support and Discussion
1

Hey- when you add too much force to an object it just goes right through walls- how do you get around this so it stops when it hits the wall and doesn’t just rocket through them? EXAMPLE: just make a cube with a 100 force head straight into a wall, it’ll just go straight through the wall…

2

The Blender game engine is not known for high-speed collisions. Plus, 100 force is wayyyyyyyyy too much for any game engine to handle. You must reduce the amount of force you use.

3

or use 2.25. it lacks some new features but you rarely have this problem.

4

or use 2.25. it lacks some new features but you rarely have this problem.

Isn’t the only reason it has better collisions is because it has the “Solid Collision Library”? I think it was remove in all the versons after 2.25 because the original creator of the Solid Collision Library didn’t want this stuff open source or somethink like that.

I wish we had our Solid Collision Library back.

5

I have noticed that high-speed objects go through more when they are smaller, have less mass, and are going perpendicular to the other object.

6

You can also try Ctrl-A (set scale & rotation) on your dynamic object AND your target object, that sometimes helps. You might also try changing those objects bounds to Convex Hull Polytopes type, then Ctrl A again.
Also be aware that high velocities and low frame rates can cause moving objects to seem to pass thru solids (or other dynamics, for that matter). You might see a difference if you just Enable All Frames in the Game Menu, but it WILL slow the general fps to compensate.

Lefty

7

Thanks for all the tips- Lefty the enable all frames really helped out the overall game look and it helped bouncing a little- the best thing I found to do was just select everything with (A) and then scale it down by 90%, then scale all your forces down by 90% too- since a smaller force on a smaller object is the same as a large force on a large object, only now the game engine doesn’t hate me :wink:

8

Well done! Looking forward to see what you come up with!!!

Lefty

9

Also, try using linV. I think its more reliable than Dloc ( I’m not sure since I’m using .25 at the moment and am too lazy to check if it works myself :p)

10

the problem as I see it is if the object covers more ground than it’s width, it has the ability to pass through objects. Example:
Cube A is 1 BU on all sides. it has a force applied on it that is great enough to move it, say, 2 BU per frame (force/mass=acceleration- so if it’s mass=1, force=acceleration). The engine calculates collisions where it ends up, but if there’s a flat (or just thin) wall in the 1 meter space between it’s start and end points, it’s never detected.
Basically, I ration out speed to make sure there’s no space between an object’s start and end positions. if an object is 1 BU long, I never let it move more than 1 BU per frame.

I rambled a bit, but I hope I got my point through the mess of sleepy wordiness.