[ODE] ODE meets Quake2 derivative using BSP collider

[trebor_7 at gmx.net]

Hello people, 
This is my first post here!
I integrated ODE into my QRazor-FX engine. I run ODE only in the server game. 
I call G_RunFrame 5 times in one network frame with a step size of 0.02 
seconds to achieve a stable simulation, that means the server game runs with 
50Hz and the network with 10Hz as in Q2/Q3A.
I've started to write a native BSP collider. It traverses every geom's AABB 
and tests it against the BSP leafs, then against the BSP leaf surfaces and 
then against the BSP leaf surface triangles and creates the dContacts. 
I have implemented successfully BSP<->Sphere collisions and I get more stable 
results than using ODE's native trimesh support with OPCODE. 
I designed the BSP geom interface like any other so it should be not a very 
big problem to patch the vanilla ODE code with the BSP geom support.
The BSP collider allows material properties on each surface which is an 
advantage because if you upload one big trimesh per BSP world model, then you 
will loose all surface properties like slick, bounce, playerclip et cetera 
which affects gameplay badly.
The current interface for it is:

dGeomID  dCreateBSP(dSpaceID space); 
 void  dGeomBSPSetLengths(dGeomID box, vec_t lx, vec_t ly, vec_t lz); 
 void  dGeomBSPAddPlane(dGeomID g, vec_t a, vec_t b, vec_t c, vec_t d); 
 void  dGeomBSPAddNode(dGeomID g, int plane_num, int child0, int child1); 
 void  dGeomBSPAddLeaf(dGeomID g, int surfaces_first, int surfaces_num, int 
brushes_first, int brushes_num, int cluster, int area); 
 void  dGeomBSPAddShader(dGeomID g, int flags, int contents); 
 void  dGeomBSPAddSurface(dGeomID g, int face_type, int shader_num, const 
std::vector<vec3_c> &vertexes, const std::vector<index_t> &indexes); 
 void  dGeomBSPAddLeafSurface(dGeomID g, int num);

As you can see my interface is not in pure C and I used the STL in ODE 
internally because I use a fork anyway. I replaced the math core code with 
mine and I changed the public interface a bit e.g. dReal has become vec_t 
which existed already in Quake. I also changed the creation of dContacts to 
avoid redudant contacts which requires to change every collider in 
collision_std. :/

http://xreal.sourceforge.net/files/ODE-BSP_Sphere-Collider.avi

This video demonstrates ODE BSP<->Sphere collisions and Sphere<->Sphere 
collisions. The dropped items have a sphere as collision geom and the rockets 
aswell. 

The ODE fork can be found here:
http://cvs.sourceforge.net/viewcvs.py/xreal/qrazor-fx3/src/ode/

Project website:
http://sourceforge.net/projects/xreal

Cheers, Robert