PDA

View Full Version : OBB collision detection



chronozphere
03-02-2007, 02:55 PM
Hi fellow PGD'ers.

Does anyone know how to determine whether two Oriented Bounding Boxes intersect?? An OBB is just a box in 3d space.

I've googled for some time but i didn't find anything usefull. :(

Can anyone help me??

Thanx alot.:)

VilleK
03-02-2007, 07:59 PM
"Dynamic Collision Detection using Oriented Bounding Boxes"
http://www.geometrictools.com/Documentation/DynamicCollisionDetection.pdf

I'm not sure if its a good resource, but it is written by David Eberly who usually writes interesting stuff.

chronozphere
04-02-2007, 10:16 AM
Damn... that's very mathy stuff. :read: :think:

I'll read (and try to understand) it when i've time.
At school we're busy with line equations (owh come on.. it's so simple.. i need a challenge :razz:)
but i think i need some extra math-education before i can implement this stuff.

Are there any source-examples available on the web??

Clootie
04-02-2007, 08:51 PM
So, how about AABB - axis aligned BB? They are much simpler (in math) and efficiency difference between AABB & OBB may be not so much for your case?

IlovePascal
17-04-2007, 03:29 AM
Just before your post, there was one by Jdarling about overlaping rectangles.
The code they eventually came up with seems very simple and effective. Since Im in a similar situation to yours (limited high school education lol), I thought Id give my opinion: why don't u simply check for rectangle overlaps on two axis? i.e. check if the vertical face (front) of one box overlaps the other, and if it does, do the same with another face (top). if you get two 'True's the boxes intersect.

chronozphere
17-04-2007, 07:46 AM
I found this page very usefull:

http://gpwiki.org/index.php/Polygon_Collision

So far, i understand what they are doing. :P
This may help me with implementing OBB collision detection or other convex 3d shapes.

AABB's are indeed very simple, but i'd rather implement OBB's in my engine. :)
For Example: When making a race game, you need accurate collision detection for the cars etc... AABB's are not accurate enough for race games.