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concavity.cpp

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include <vector>

#include "concavity.h"
#include "raytri.h"
#include "bestfit.h"
#include "cd_hull.h"
#include "meshvolume.h"
#include "cd_vector.h"
#include "splitplane.h"
#include "ConvexDecomposition.h"


#define WSCALE 4
#define CONCAVE_THRESH 0.05f

namespace ConvexDecomposition
{

unsigned int getDebugColor(void)
{
        static unsigned int colors[8] =
        {
                0xFF0000,
          0x00FF00,
                0x0000FF,
                0xFFFF00,
                0x00FFFF,
                0xFF00FF,
                0xFFFFFF,
                0xFF8040
        };

        static int count = 0;

        count++;

        if ( count == 8 ) count = 0;

        assert( count >= 0 && count < 8 );

        unsigned int color = colors[count];

  return color;

}

class Wpoint
{
public:
  Wpoint(const Vector3d<double> &p,double w)
  {
    mPoint = p;
    mWeight = w;
  }

  Vector3d<double> mPoint;
  double           mWeight;
};

typedef std::vector< Wpoint > WpointVector;


static inline double DistToPt(const double *p,const double *plane)
{
        double x = p[0];
        double y = p[1];
        double z = p[2];
        double d = x*plane[0] + y*plane[1] + z*plane[2] + plane[3];
        return d;
}


static void intersect(const double *p1,const double *p2,double *split,const double *plane)
{

  double dp1 = DistToPt(p1,plane);
  double dp2 = DistToPt(p2,plane);

  double dir[3];

  dir[0] = p2[0] - p1[0];
  dir[1] = p2[1] - p1[1];
  dir[2] = p2[2] - p1[2];

  double dot1 = dir[0]*plane[0] + dir[1]*plane[1] + dir[2]*plane[2];
  double dot2 = dp1 - plane[3];

  double    t = -(plane[3] + dot2 ) / dot1;

  split[0] = (dir[0]*t)+p1[0];
  split[1] = (dir[1]*t)+p1[1];
  split[2] = (dir[2]*t)+p1[2];

}


class CTri
{
public:
        CTri(void) { };

  CTri(const double *p1,const double *p2,const double *p3,unsigned int i1,unsigned int i2,unsigned int i3)
  {
    mProcessed = 0;
    mI1 = i1;
    mI2 = i2;
    mI3 = i3;

        mP1.Set(p1);
        mP2.Set(p2);
        mP3.Set(p3);

        mPlaneD = mNormal.ComputePlane(mP1,mP2,mP3);
        }

  double Facing(const CTri &t)
  {
                double d = mNormal.Dot(t.mNormal);
                return d;
  }

  // clip this line segment against this triangle.
  bool clip(const Vector3d<double> &start,Vector3d<double> &end) const
  {
    Vector3d<double> sect;

    bool hit = lineIntersectsTriangle(start.Ptr(), end.Ptr(), mP1.Ptr(), mP2.Ptr(), mP3.Ptr(), sect.Ptr() );

    if ( hit )
    {
      end = sect;
    }
    return hit;
  }

        bool Concave(const Vector3d<double> &p,double &distance,Vector3d<double> &n) const
        {
                n.NearestPointInTriangle(p,mP1,mP2,mP3);
                distance = p.Distance(n);
                return true;
        }

        void addTri(unsigned int *indices,unsigned int i1,unsigned int i2,unsigned int i3,unsigned int &tcount) const
        {
                indices[tcount*3+0] = i1;
                indices[tcount*3+1] = i2;
                indices[tcount*3+2] = i3;
                tcount++;
        }

        double getVolume(ConvexDecompInterface *callback) const
        {
                unsigned int indices[8*3];


    unsigned int tcount = 0;

    addTri(indices,0,1,2,tcount);
    addTri(indices,3,4,5,tcount);

    addTri(indices,0,3,4,tcount);
    addTri(indices,0,4,1,tcount);

    addTri(indices,1,4,5,tcount);
    addTri(indices,1,5,2,tcount);

    addTri(indices,0,3,5,tcount);
    addTri(indices,0,5,2,tcount);

    const double *vertices = mP1.Ptr();

                if ( callback )
                {
                        unsigned int color = getDebugColor();

#if 0
                Vector3d<double> d1 = mNear1;
                Vector3d<double> d2 = mNear2;
                Vector3d<double> d3 = mNear3;

                callback->ConvexDebugPoint(mP1.Ptr(),0.01f,0x00FF00);
                callback->ConvexDebugPoint(mP2.Ptr(),0.01f,0x00FF00);
                callback->ConvexDebugPoint(mP3.Ptr(),0.01f,0x00FF00);
                callback->ConvexDebugPoint(d1.Ptr(),0.01f,0xFF0000);
                callback->ConvexDebugPoint(d2.Ptr(),0.01f,0xFF0000);
                callback->ConvexDebugPoint(d3.Ptr(),0.01f,0xFF0000);

                callback->ConvexDebugTri(mP1.Ptr(), d1.Ptr(),  d1.Ptr(),0x00FF00);
                callback->ConvexDebugTri(mP2.Ptr(), d2.Ptr(),  d2.Ptr(),0x00FF00);
                callback->ConvexDebugTri(mP3.Ptr(), d3.Ptr(),  d3.Ptr(),0x00FF00);

#else
                        for (unsigned int i=0; i<tcount; i++)
                        {
                                unsigned int i1 = indices[i*3+0];
                                unsigned int i2 = indices[i*3+1];
                                unsigned int i3 = indices[i*3+2];

                                const double *p1 = &vertices[ i1*3 ];
                                const double *p2 = &vertices[ i2*3 ];
                                const double *p3 = &vertices[ i3*3 ];

                                callback->ConvexDebugTri(p1,p2,p3,color);

                        }
#endif
                }

                double v = computeMeshVolume(mP1.Ptr(), tcount, indices );

                return v;

        }

        double raySect(const Vector3d<double> &p,const Vector3d<double> &dir,Vector3d<double> &sect) const
        {
                double plane[4];

    plane[0] = mNormal.x;
    plane[1] = mNormal.y;
    plane[2] = mNormal.z;
    plane[3] = mPlaneD;

                Vector3d<double> dest = p+dir*100000;

    intersect( p.Ptr(), dest.Ptr(), sect.Ptr(), plane );

    return sect.Distance(p); // return the intersection distance.

        }

  double planeDistance(const Vector3d<double> &p) const
  {
                double plane[4];

    plane[0] = mNormal.x;
    plane[1] = mNormal.y;
    plane[2] = mNormal.z;
    plane[3] = mPlaneD;

                return DistToPt( p.Ptr(), plane );

  }

        bool samePlane(const CTri &t) const
        {
                const double THRESH = 0.001f;
    double dd = fabs( t.mPlaneD - mPlaneD );
    if ( dd > THRESH ) return false;
    dd = fabs( t.mNormal.x - mNormal.x );
    if ( dd > THRESH ) return false;
    dd = fabs( t.mNormal.y - mNormal.y );
    if ( dd > THRESH ) return false;
    dd = fabs( t.mNormal.z - mNormal.z );
    if ( dd > THRESH ) return false;
    return true;
        }

        bool hasIndex(unsigned int i) const
        {
                if ( i == mI1 || i == mI2 || i == mI3 ) return true;
                return false;
        }

  bool sharesEdge(const CTri &t) const
  {
    bool ret = false;
    unsigned int count = 0;

                if ( t.hasIndex(mI1) ) count++;
          if ( t.hasIndex(mI2) ) count++;
                if ( t.hasIndex(mI3) ) count++;

    if ( count >= 2 ) ret = true;

    return ret;
  }

  void debug(unsigned int color,ConvexDecompInterface *callback)
  {
    callback->ConvexDebugTri( mP1.Ptr(), mP2.Ptr(), mP3.Ptr(), color );
    callback->ConvexDebugTri( mP1.Ptr(), mP1.Ptr(), mNear1.Ptr(), 0xFF0000 );
    callback->ConvexDebugTri( mP2.Ptr(), mP2.Ptr(), mNear2.Ptr(), 0xFF0000 );
    callback->ConvexDebugTri( mP2.Ptr(), mP3.Ptr(), mNear3.Ptr(), 0xFF0000 );
    callback->ConvexDebugPoint( mNear1.Ptr(), 0.01f, 0xFF0000 );
    callback->ConvexDebugPoint( mNear2.Ptr(), 0.01f, 0xFF0000 );
    callback->ConvexDebugPoint( mNear3.Ptr(), 0.01f, 0xFF0000 );
  }

  double area(void)
  {
                double a = mConcavity*mP1.Area(mP2,mP3);
    return a;
  }

  void addWeighted(WpointVector &list,ConvexDecompInterface *callback)
  {

    Wpoint p1(mP1,mC1);
    Wpoint p2(mP2,mC2);
    Wpoint p3(mP3,mC3);

                Vector3d<double> d1 = mNear1 - mP1;
                Vector3d<double> d2 = mNear2 - mP2;
                Vector3d<double> d3 = mNear3 - mP3;

                d1*=WSCALE;
                d2*=WSCALE;
                d3*=WSCALE;

                d1 = d1 + mP1;
                d2 = d2 + mP2;
          d3 = d3 + mP3;

    Wpoint p4(d1,mC1);
    Wpoint p5(d2,mC2);
    Wpoint p6(d3,mC3);

    list.push_back(p1);
    list.push_back(p2);
    list.push_back(p3);

    list.push_back(p4);
    list.push_back(p5);
    list.push_back(p6);

#if 0
                callback->ConvexDebugPoint(mP1.Ptr(),0.01f,0x00FF00);
                callback->ConvexDebugPoint(mP2.Ptr(),0.01f,0x00FF00);
                callback->ConvexDebugPoint(mP3.Ptr(),0.01f,0x00FF00);
                callback->ConvexDebugPoint(d1.Ptr(),0.01f,0xFF0000);
                callback->ConvexDebugPoint(d2.Ptr(),0.01f,0xFF0000);
                callback->ConvexDebugPoint(d3.Ptr(),0.01f,0xFF0000);

                callback->ConvexDebugTri(mP1.Ptr(), d1.Ptr(),  d1.Ptr(),0x00FF00);
                callback->ConvexDebugTri(mP2.Ptr(), d2.Ptr(),  d2.Ptr(),0x00FF00);
                callback->ConvexDebugTri(mP3.Ptr(), d3.Ptr(),  d3.Ptr(),0x00FF00);

                Vector3d<double> np1 = mP1 + mNormal*0.05f;
                Vector3d<double> np2 = mP2 + mNormal*0.05f;
                Vector3d<double> np3 = mP3 + mNormal*0.05f;

                callback->ConvexDebugTri(mP1.Ptr(), np1.Ptr(), np1.Ptr(), 0xFF00FF );
                callback->ConvexDebugTri(mP2.Ptr(), np2.Ptr(), np2.Ptr(), 0xFF00FF );
                callback->ConvexDebugTri(mP3.Ptr(), np3.Ptr(), np3.Ptr(), 0xFF00FF );

                callback->ConvexDebugPoint( np1.Ptr(), 0.01F, 0XFF00FF );
                callback->ConvexDebugPoint( np2.Ptr(), 0.01F, 0XFF00FF );
                callback->ConvexDebugPoint( np3.Ptr(), 0.01F, 0XFF00FF );

#endif



  }

  Vector3d<double>      mP1;
  Vector3d<double>      mP2;
  Vector3d<double>      mP3;
  Vector3d<double> mNear1;
  Vector3d<double> mNear2;
  Vector3d<double> mNear3;
  Vector3d<double> mNormal;
  double           mPlaneD;
  double           mConcavity;
  double           mC1;
  double           mC2;
  double           mC3;
  unsigned int    mI1;
  unsigned int    mI2;
  unsigned int    mI3;
  int             mProcessed; // already been added...
};

typedef std::vector< CTri > CTriVector;

bool featureMatch(CTri &m,const CTriVector &tris,ConvexDecompInterface *callback,const CTriVector &input_mesh)
{

  bool ret = false;

  double neardot = 0.707f;

  m.mConcavity = 0;

        //gLog->Display("*********** FEATURE MATCH *************\r\n");
        //gLog->Display("Plane: %0.4f,%0.4f,%0.4f   %0.4f\r\n", m.mNormal.x, m.mNormal.y, m.mNormal.z, m.mPlaneD );
        //gLog->Display("*********************************************\r\n");

        CTriVector::const_iterator i;

        CTri nearest;

  double near[3] = { 1e9, 1e9, 1e9 };

        for (i=tris.begin(); i!=tris.end(); ++i)
        {
                const CTri &t = (*i);


        //gLog->Display("   HullPlane: %0.4f,%0.4f,%0.4f   %0.4f\r\n", t.mNormal.x, t.mNormal.y, t.mNormal.z, t.mPlaneD );

                if ( t.samePlane(m) )
                {
                        //gLog->Display("*** PLANE MATCH!!!\r\n");
                        ret = false;
                        break;
                }

          double dot = t.mNormal.Dot(m.mNormal);

          if ( dot > neardot )
          {

      double d1 = t.planeDistance( m.mP1 );
      double d2 = t.planeDistance( m.mP2 );
      double d3 = t.planeDistance( m.mP3 );

      if ( d1 > 0.001f || d2 > 0.001f || d3 > 0.001f ) // can't be near coplaner!
      {

                neardot = dot;

        Vector3d<double> n1,n2,n3;

        t.raySect( m.mP1, m.mNormal, m.mNear1 );
        t.raySect( m.mP2, m.mNormal, m.mNear2 );
        t.raySect( m.mP3, m.mNormal, m.mNear3 );

                                nearest = t;

                        ret = true;
                  }

          }
        }

        if ( ret )
        {
    if ( 0 )
    {
      CTriVector::const_iterator i;
      for (i=input_mesh.begin(); i!=input_mesh.end(); ++i)
      {
        const CTri &c = (*i);
        if ( c.mI1 != m.mI1 && c.mI2 != m.mI2 && c.mI3 != m.mI3 )
        {
                          c.clip( m.mP1, m.mNear1 );
                                  c.clip( m.mP2, m.mNear2 );
                                  c.clip( m.mP3, m.mNear3 );
        }
      }
    }

          //gLog->Display("*********************************************\r\n");
        //gLog->Display("   HullPlaneNearest: %0.4f,%0.4f,%0.4f   %0.4f\r\n", nearest.mNormal.x, nearest.mNormal.y, nearest.mNormal.z, nearest.mPlaneD );

                m.mC1 = m.mP1.Distance( m.mNear1 );
                m.mC2 = m.mP2.Distance( m.mNear2 );
                m.mC3 = m.mP3.Distance( m.mNear3 );

                m.mConcavity = m.mC1;

                if ( m.mC2 > m.mConcavity ) m.mConcavity = m.mC2;
                if ( m.mC3 > m.mConcavity ) m.mConcavity = m.mC3;

    #if 0
                callback->ConvexDebugTri( m.mP1.Ptr(), m.mP2.Ptr(), m.mP3.Ptr(), 0x00FF00 );
                callback->ConvexDebugTri( m.mNear1.Ptr(), m.mNear2.Ptr(), m.mNear3.Ptr(), 0xFF0000 );

                callback->ConvexDebugTri( m.mP1.Ptr(), m.mP1.Ptr(), m.mNear1.Ptr(), 0xFFFF00 );
                callback->ConvexDebugTri( m.mP2.Ptr(), m.mP2.Ptr(), m.mNear2.Ptr(), 0xFFFF00 );
                callback->ConvexDebugTri( m.mP3.Ptr(), m.mP3.Ptr(), m.mNear3.Ptr(), 0xFFFF00 );
    #endif

        }
        else
        {
                //gLog->Display("No match\r\n");
        }

        //gLog->Display("*********************************************\r\n");
        return ret;
}

bool isFeatureTri(CTri &t,CTriVector &flist,double fc,ConvexDecompInterface *callback,unsigned int color)
{
  bool ret = false;

  if ( t.mProcessed == 0 ) // if not already processed
  {

    double c = t.mConcavity / fc; // must be within 80% of the concavity of the parent.

    if ( c > 0.85f )
    {
      // see if this triangle is a 'feature' triangle.  Meaning it shares an
      // edge with any existing feature triangle and is within roughly the same
      // concavity of the parent.
                        if ( flist.size() )
                        {
                          CTriVector::iterator i;
                          for (i=flist.begin(); i!=flist.end(); ++i)
                          {
                                  CTri &ftri = (*i);
                                  if ( ftri.sharesEdge(t) )
                                  {
                                          t.mProcessed = 2; // it is now part of a feature.
                                          flist.push_back(t); // add it to the feature list.
//                                        callback->ConvexDebugTri( t.mP1.Ptr(), t.mP2.Ptr(),t.mP3.Ptr(), color );
                                          ret = true;
                                          break;
          }
                                }
                        }
                        else
                        {
                                t.mProcessed = 2;
                                flist.push_back(t); // add it to the feature list.
//                              callback->ConvexDebugTri( t.mP1.Ptr(), t.mP2.Ptr(),t.mP3.Ptr(), color );
                                ret = true;
                        }
    }
    else
    {
      t.mProcessed = 1; // eliminated for this feature, but might be valid for the next one..
    }

  }
  return ret;
}

double computeConcavity(unsigned int vcount,
                       const double *vertices,
                       unsigned int tcount,
                       const unsigned int *indices,
                       ConvexDecompInterface *callback,
                       double *plane,      // plane equation to split on
                       double &volume)
{


        double cret = 0;
        volume = 1;

        HullResult  result;
  HullLibrary hl;
  HullDesc    desc;

        desc.mMaxVertices = 256;
        desc.SetHullFlag(QF_TRIANGLES);


  desc.mVcount       = vcount;
  desc.mVertices     = vertices;
  desc.mVertexStride = sizeof(double)*3;

  HullError ret = hl.CreateConvexHull(desc,result);

  if ( ret == QE_OK )
  {

                double bmin[3];
                double bmax[3];

    double diagonal = getBoundingRegion( result.mNumOutputVertices, result.mOutputVertices, sizeof(double)*3, bmin, bmax );

                double dx = bmax[0] - bmin[0];
                double dy = bmax[1] - bmin[1];
                double dz = bmax[2] - bmin[2];

                Vector3d<double> center;

                center.x = bmin[0] + dx*0.5f;
                center.y = bmin[1] + dy*0.5f;
                center.z = bmin[2] + dz*0.5f;

                double boundVolume = dx*dy*dz;

                volume = computeMeshVolume2( result.mOutputVertices, result.mNumFaces, result.mIndices );

#if 1
                // ok..now..for each triangle on the original mesh..
                // we extrude the points to the nearest point on the hull.
                const unsigned int *source = result.mIndices;

                CTriVector tris;

    for (unsigned int i=0; i<result.mNumFaces; i++)
    {
        unsigned int i1 = *source++;
        unsigned int i2 = *source++;
        unsigned int i3 = *source++;

        const double *p1 = &result.mOutputVertices[i1*3];
        const double *p2 = &result.mOutputVertices[i2*3];
        const double *p3 = &result.mOutputVertices[i3*3];

//                      callback->ConvexDebugTri(p1,p2,p3,0xFFFFFF);

                        CTri t(p1,p2,p3,i1,i2,i3); //
                        tris.push_back(t);
                }

    // we have not pre-computed the plane equation for each triangle in the convex hull..

                double totalVolume = 0;

                CTriVector ftris; // 'feature' triangles.

                const unsigned int *src = indices;


    double maxc=0;


                if ( 1 )
                {
      CTriVector input_mesh;
      if ( 1 )
      {
                    const unsigned int *src = indices;
                        for (unsigned int i=0; i<tcount; i++)
                        {

                unsigned int i1 = *src++;
                unsigned int i2 = *src++;
                unsigned int i3 = *src++;

                const double *p1 = &vertices[i1*3];
                const double *p2 = &vertices[i2*3];
                const double *p3 = &vertices[i3*3];

                                CTri t(p1,p2,p3,i1,i2,i3);
          input_mesh.push_back(t);
        }
      }

      CTri  maxctri;

                        for (unsigned int i=0; i<tcount; i++)
                        {

                unsigned int i1 = *src++;
                unsigned int i2 = *src++;
                unsigned int i3 = *src++;

                const double *p1 = &vertices[i1*3];
                const double *p2 = &vertices[i2*3];
                const double *p3 = &vertices[i3*3];

                                CTri t(p1,p2,p3,i1,i2,i3);

                                featureMatch(t, tris, callback, input_mesh );

                                if ( t.mConcavity > CONCAVE_THRESH )
                                {

          if ( t.mConcavity > maxc )
          {
            maxc = t.mConcavity;
            maxctri = t;
          }

                                double v = t.getVolume(0);
                                totalVolume+=v;
                                ftris.push_back(t);
                        }

                        }
                }

          if ( ftris.size()  && 0 )
          {

      // ok..now we extract the triangles which form the maximum concavity.
      CTriVector major_feature;
      double maxarea = 0;

      while ( maxc > CONCAVE_THRESH  )
      {

        unsigned int color = getDebugColor();  //

        CTriVector flist;

        bool found;

        double totalarea = 0;

        do
        {
          found = false;
          CTriVector::iterator i;
          for (i=ftris.begin(); i!=ftris.end(); ++i)
          {
            CTri &t = (*i);
            if ( isFeatureTri(t,flist,maxc,callback,color) )
            {
              found = true;
              totalarea+=t.area();
            }
                                }
        } while ( found );


        if ( totalarea > maxarea )
        {
          major_feature = flist;
          maxarea = totalarea;
        }

        maxc = 0;

        for (unsigned int i=0; i<ftris.size(); i++)
        {
          CTri &t = ftris[i];
          if ( t.mProcessed != 2 )
          {
            t.mProcessed = 0;
            if ( t.mConcavity > maxc )
            {
              maxc = t.mConcavity;
            }
          }
        }
      }

      unsigned int color = getDebugColor();

      WpointVector list;
      for (unsigned int i=0; i<major_feature.size(); ++i)
      {
        major_feature[i].addWeighted(list,callback);
        major_feature[i].debug(color,callback);
      }

      getBestFitPlane( list.size(), &list[0].mPoint.x, sizeof(Wpoint), &list[0].mWeight, sizeof(Wpoint), plane );

                computeSplitPlane( vcount, vertices, tcount, indices, callback, plane );


                }
          else
          {
                computeSplitPlane( vcount, vertices, tcount, indices, callback, plane );
          }
#endif

                cret = totalVolume;

          hl.ReleaseResult(result);
  }


        return cret;
}


};

---

convex_decomposition
Author(s): John Ratcliff
autogenerated on Tue Mar 5 12:17:26 2013