kd-tree and sph

[Mickael POUCHOL]

Hi,

I'm using libkdtree++ for 2D SPH simulation for nearest neighbour 
search. The structure stored in the kd-tree is :


struct ParticlePtr {
  typedef float value_type;

  inline value_type operator[](size_t const N) const { return 
ptr->position[N]; }
  // The position if of type vec2f
  Particle *ptr;
};

For each particle in the simulation, I use the tree to get its 
neighbours with a call to : t.find_within_range(current_particle, RANGE, 
std::back_inserter(v));
Sometimes I would like to query the tree with a vec2f value and not with 
a ParticlePtr. Is there a way to do that?

Secondly I would like to use another kd-tree to store segments (or 
triangles in 3D) and query it with a ray in the collision detection 
phase. I didn't not understand how to define such a kd-tree with the lib.


Thanks for your help,
Mickael