## What is the Simplest Collision System You Can Think Of?

A place for users of OGRE to discuss ideas and experiences of utilitising OGRE in their games / demos / applications.
kabbotta
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### What is the Simplest Collision System You Can Think Of?

I'm creating a game that is somewhat similar to Knights of the Old Republic. There won't be any jumping and relatively simple floorplans. I highly doubt I will need a full physics engine. I'm not even sure I'll need gravity.

So what is the simplest collision system you can imagine for a limited scenario like this? The most dynamic thing I'll need is the ability to walk up slanted surfaces. There will be no complicated bullet collisions or pixel-perfect object collision needed at all. It will just be collisions with generally blocky objects.
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PhilipLB
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### Re: What is the Simplest Collision System You Can Think Of?

Sphere vs. Sphere is more than easy but might not do it here.
Axis Aligned Bounding Boxes are simple, too. But I think you want to rotate your entities. So Bounding Boxes would do it IMHO.
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amartin
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### Re: What is the Simplest Collision System You Can Think Of?

The simplest collision system is to use Minimal ogre collision with two rays one down and one in the direction of travel. The down ray handles moving you up and down the other ray stops you walking through things. Add extra rays for additional complexity as desired.

Herb
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### Re: What is the Simplest Collision System You Can Think Of?

agree with amartin, but keep in mind that will do bounding box collisions. If your bounding boxes are fairly tight to models, that should work good. You can also do raycasting down to the polygon level (search in the Ogre wiki to find it), but it's more expensive. I've found in my simple games, that I use a mix of both depending on the accuracy needed for each case.

kabbotta
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### Re: What is the Simplest Collision System You Can Think Of?

The minimal Ogre collision system looks like just about what I wanted. Thanks, guys!
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Zonder
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### Re: What is the Simplest Collision System You Can Think Of?

I suggest you have a read of this article it explains the benefit of using an ellipsoid instead of a sphere for collision detection for humanoids. I would first use a AABB collision detection to get potential collision surfaces first then use the ellipsoid method after.

http://www.gamedev.net/page/resources/_ ... -ell-r1026
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