Forest/tree server collision detection

/// Casts a ray and obtain collision information, returns true if RayInfo is modified.
   ///
   /// @param   start   Start point of ray
   /// @param   end   End point of ray
   /// @param   info   Collision information obtained (out)
   virtual bool castRay(const Point3F &start, const Point3F &end, RayInfo* info);
 
   /// Builds a convex hull for this object.
   ///
   /// Think of a convex hull as a low-res mesh which covers, as tightly as 
   /// possible, the object mesh, and is used as a collision mesh.
   /// @param   box   
   /// @param   convex   Convex mesh generated (out)
   virtual void buildConvex(const Box3F& box,Convex* convex);
    
   /// Builds a list of polygons which intersect a bounding volume.
   ///
   /// This will use either the sphere or the box, not both, the
   /// SceneObject implimentation ignores sphere.
   ///
   /// @see AbstractPolyList
   /// @param   polyList   Poly list build (out)
   /// @param   box        Box bounding volume
   /// @param   sphere     Sphere bounding volume 
   virtual bool buildPolyList(AbstractPolyList* polyList, const Box3F &box, const SphereF &sphere);