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BVH_split_rule.h

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#ifndef COLLISION_CHECKING_BVH_SPLIT_RULE_H
#define COLLISION_CHECKING_BVH_SPLIT_RULE_H


#include "collision_checking/BVH_defs.h"
#include "collision_checking/primitive.h"
#include "collision_checking/vec_3f.h"
#include "collision_checking/obb.h"
#include <ros/console.h>
#include <vector>

namespace collision_checking
{

enum SplitMethodType {SPLIT_METHOD_MEAN, SPLIT_METHOD_MEDIAN, SPLIT_METHOD_BV_CENTER};


template<typename BV>
class BVSplitRule
{
public:

  BVSplitRule()
  {
    split_method = SPLIT_METHOD_MEAN;
  }

  void setSplitType(SplitMethodType method)
  {
    split_method = method;
  }

  void set(Vec3f* vertices_, Triangle* tri_indices_, BVHModelType type_)
  {
    vertices = vertices_;
    tri_indices = tri_indices_;
    type = type_;
  }

  void computeRule(const BV& bv, unsigned int* primitive_indices, int num_primitives)
  {
    switch(split_method)
    {
      case SPLIT_METHOD_MEAN:
        computeRule_mean(bv, primitive_indices, num_primitives);
        break;
      case SPLIT_METHOD_MEDIAN:
        computeRule_median(bv, primitive_indices, num_primitives);
        break;
      case SPLIT_METHOD_BV_CENTER:
        computeRule_bvcenter(bv, primitive_indices, num_primitives);
        break;
      default:
        ROS_WARN_STREAM("Split method not supported");
    }
  }

  bool operator()(const Vec3f& q) const
  {
    return q[split_axis] > split_value;
  }

  void clear()
  {
    vertices = NULL;
    tri_indices = NULL;
    type = BVH_MODEL_UNKNOWN;
  }

private:

  int split_axis;

  BVH_REAL split_value;

  Vec3f* vertices;
  Triangle* tri_indices;
  BVHModelType type;
  SplitMethodType split_method;

  void computeRule_bvcenter(const BV& bv, unsigned int* primitive_indices, int num_primitives)
  {
    Vec3f center = bv.center();
    int axis = 2;

    if(bv.width() >= bv.height() && bv.width() >= bv.depth())
      axis = 0;
    else if(bv.height() >= bv.width() && bv.height() >= bv.depth())
      axis = 1;

    split_axis = axis;
    split_value = center[axis];
  }

  void computeRule_mean(const BV& bv, unsigned int* primitive_indices, int num_primitives)
  {
    int axis = 2;

    if(bv.width() >= bv.height() && bv.width() >= bv.depth())
      axis = 0;
    else if(bv.height() >= bv.width() && bv.height() >= bv.depth())
      axis = 1;

    split_axis = axis;
    BVH_REAL sum = 0;

    if(type == BVH_MODEL_TRIANGLES)
    {
      for(int i = 0; i < num_primitives; ++i)
      {
        const Triangle& t = tri_indices[primitive_indices[i]];
        sum += ((vertices[t[0]][split_axis] + vertices[t[1]][split_axis] + vertices[t[2]][split_axis]) / 3);
      }
    }
    else if(type == BVH_MODEL_POINTCLOUD)
    {
      for(int i = 0; i < num_primitives; ++i)
      {
        sum += vertices[primitive_indices[i]][split_axis];
      }
    }

    split_value = sum / num_primitives;
  }

  void computeRule_median(const BV& bv, unsigned int* primitive_indices, int num_primitives)
  {
    int axis = 2;

    if(bv.width() >= bv.height() && bv.width() >= bv.depth())
      axis = 0;
    else if(bv.height() >= bv.width() && bv.height() >= bv.depth())
      axis = 1;

    split_axis = axis;
    std::vector<BVH_REAL> proj(num_primitives);

    if(type == BVH_MODEL_TRIANGLES)
    {
      for(int i = 0; i < num_primitives; ++i)
      {
        const Triangle& t = tri_indices[primitive_indices[i]];
        proj[i] = (vertices[t[0]][split_axis] + vertices[t[1]][split_axis] + vertices[t[2]][split_axis]) / 3;
      }
    }
    else if(type == BVH_MODEL_POINTCLOUD)
    {
      for(int i = 0; i < num_primitives; ++i)
        proj[i] = vertices[primitive_indices[i]][split_axis];
    }

    std::sort(proj.begin(), proj.end());

    if(num_primitives % 2 == 1)
    {
      split_value = proj[(num_primitives - 1) / 2];
    }
    else
    {
      split_value = (proj[num_primitives / 2] + proj[num_primitives / 2 - 1]) / 2;
    }
  }
};



template<>
class BVSplitRule<OBB>
{
public:

  BVSplitRule()
  {
    split_method = SPLIT_METHOD_MEAN;
  }

  void setSplitType(SplitMethodType method)
  {
    split_method = method;
  }

  void set(Vec3f* vertices_, Triangle* tri_indices_, BVHModelType type_)
  {
    vertices = vertices_;
    tri_indices = tri_indices_;
    type = type_;
  }

  void computeRule(const OBB& bv, unsigned int* primitive_indices, int num_primitives)
  {
    Vec3f center = bv.center();
    split_vector = bv.axis[0];
    split_value = center[0];
  }

  bool operator()(const Vec3f& q) const
  {
    return split_vector.dot(Vec3f(q[0], q[1], q[2])) > split_value;
  }

  void clear()
  {
    vertices = NULL;
    tri_indices = NULL;
    type = BVH_MODEL_UNKNOWN;
  }

private:

  void computeRule_bvcenter(const OBB& bv, unsigned int* primitive_indices, int num_primitives);

  void computeRule_mean(const OBB& bv, unsigned int* primitive_indices, int num_primitives);

  void computeRule_median(const OBB& bv, unsigned int* primitive_indices, int num_primitives);

  BVH_REAL split_value;
  Vec3f split_vector;

  Vec3f* vertices;
  Triangle* tri_indices;
  BVHModelType type;
  SplitMethodType split_method;
};

}

#endif

---

collision_checking
Author(s): Jia Pan, Dinesh Manocha (UNC, Chapel Hill)
autogenerated on Fri Mar 1 14:56:47 2013