# Strange BoundigBox

feanor91

15-11-2008 07:51:24

Hi

I want to know why my bounding box is like that :

That is size of the bounding box is greater than object.

Therefore on another position of my object like that :

Bounding box size is correct.

My problem is that I want sides of my kite to be in conatact with the floor. So how can I do if I can't use bounding box?

galaktor

15-11-2008 13:59:42

I'd guess this must be some mesh issue...

feanor91

15-11-2008 15:31:52

Waou. And Like what? Under Max, all seems right.

galaktor

15-11-2008 16:01:33

I am not sure, maybe something gets messed up during conversion or so. I am not a specialist for ogre meshes, sorry. It just occurs to me to be the most probable reason.

ProfesorX

15-11-2008 20:35:35

There is nothing strange.

The Bounding Box that OGRE uses/defines are AABB (Axis Aligned Bounding Box).

I think that what you want is a OBB (Oriented Bounding Box)

See this article:

http://www.gamasutra.com/features/20000203/lander_01.htm

AndroidAdam

15-11-2008 22:34:32

Does Ogre/Mogre contain any classes for a Oriented Bounding Box by itself?

galaktor

15-11-2008 22:42:58

Doesn't the bounding box look to big compared to the object, even though the object is rotated?

AndroidAdam

15-11-2008 23:06:26

According to that article, basically rotating the mesh forces the box to expand in order to keep the mesh fully inside. An oriented Box, rotates itself to the orientation of the mesh.

feanor91

16-11-2008 08:08:31

Thanks guys

So I think that is not possible to work properly neither with AABB nor OOBB, to detect ground collisions, I must work withNewton. Too bad.

feanor91

18-11-2008 11:30:26

Hi

I have try with Newton, but it doesn't work as I want. That I want to say is that Newton do the job well, I can apply a velocity to my kite to make it down and smatch the ground BUT....the kite didn'r stop when it reaches ground so, I cant get off my coordinates of altitude because I don't now when the collision occurs.

So, any idea to use another wya than newton?

Meanwhile, I post to Newton forum for anybody have an idea to detect when colision ocuured

galaktor

18-11-2008 12:21:53

Instead of using one single bounding box, you could place 3 (or better more) small dummy bodies at the extrema of your kite. You would have one at the "nose", one at each wing-tip and ideally a few more in between. Additionally you could use an OOBB for an earlier stage of collision detection, sort of a "preview".

feanor91

18-11-2008 14:37:09

Good idea, I will look this way. Thanks.