   High Collision Data
  what options do I have open to me for the highest LOD level for my collision meshes? I'll be using AABB's and Bounding Spheres for the low detail levels, but wondering whats the best for the high detail.From looking around, it tends to be Convex meshes and K-Dops. Are there any others that are good for real time collision? and what are the pros and cons?Thanks   
  It totally depends on the needs of your game and how much processing power you have to spare (ie how much is left after the rest of your game uses it's slice).give some more info about your game and you can get a better answer!However, in collision detection you generally have broad phase and narrow phase collision detection.Broad phase is there to cull out objects as quickly as possible that dont even get close to intersecting your intersection test.One example of broadphase would be storing all your objects in a grid, and using the grid to help preform a quick AABB test to throw out most of the objects in your world.After broadphase comes narrow phase.Narrow phase is where you do things such as testing the line segment created by shooting a bullet against the actual model data itself to see where if it hit anything.If you have a good broadphase, depending on your needs, your narrow phase could actually test against the actual model data itself to see if there were any hits and if so where.But, again, what are your needs, what kind of game are you making?There is no one right answer for every game, but there are some best practices for certain types of games (:Edit: but btw, another option for you if you are collision testing against 3d animation meshes would be to test against the bones, or just specific bones you cared about (ie you could throw out facial bones)   ;  what accurate collision detection do you need? Mesh-Mesh is rarely useful in games. Objects are simplified by proxies (basic primitives like sphere, convex hulls, boxes, capsules, cylinders, ect...), and you can increase or decrease the number down depending on the context. For example, ragdolls have proxies for each limbs and body parts (usually capsules, boxes), where as character controllers are just a box, or a few spheres. Bullet collision detection is usually ray vs geometry (the character geometry), speed up with some proxies. Vehicle vs mesh is usually also a collection of primitives.Mesh-mesh is tricky, mainly because they represent closed volumes badly, whereas primitives have a well defined, closed volume. So with accurate' mesh mesh, you end up with loads of spurious contact info that you need to sort and sift through (contact reduction) to derive meaningful, reduced contact info.   ;  Maybe i wasnt clear. My question is. What kinds of collision representation is used for collision in games these days for the highest Collision LOD. So if the lower representations, are things like AABB's, BSpheres, Capsules etc etc, what do they use for the more accurate tests, after the lower quality tests pass? Im aware of K-Dops and Convex hulls. Just wondering if there is anything else?At the moment, im thinkng of usingscene partitionFirstTest - BSphereSecondTest - AABB or OOBLastTest - K-Dop or ConvexHullsFrom my understanding, if i use K-Dops, i can use distance of the planes, and if i use Convex Hulls, i'll be using sat.Just wondering if anyone has any advice on which to use?From my understanding;- Convex hulls, more costly to compute- Multiple convex hulls will need to be stored if the model is concave- Gives a better representation for concave models- K-Dopshulls, very simple to compute- Very small storage space- Gives bad representation for concave modelsIve not been able to find much info on K-Dops, so if anyone has any links, id appreciate themThe game will be a general FPS shooter. ;  In physics engines, they use the GJK-type technique, which is an iterative process, and can be applied to any form of convex objects. Concave objects are usually represented with a collection of convex objects. But I'm not very familiar with K-Dops, and their advantages over simpler volumes (AABBs / OBBs being a specific class of kdops). Personally I think you can merge the first and second test into one. If you use a quadtree / kd-tree for your scene, or sweep and prune for your objects, a single AABB will do the trick. The cost of computing convex hulls, optimising them, shouldn't be a problem as this is pre-processed.   