source: GTP/trunk/Lib/Vis/Preprocessing/src/RssPreprocessor.cpp @ 1027

#include "SceneGraph.h"
#include "KdTree.h"
#include "RssPreprocessor.h"
#include "X3dExporter.h"
#include "Environment.h"
#include "MutualVisibility.h"
#include "Polygon3.h"
#include "ViewCell.h"
#include "VssRay.h"
#include "RssTree.h"
#include "ViewCellsManager.h"
#include "RenderSimulator.h"
#include "GlRenderer.h"

namespace GtpVisibilityPreprocessor {


static bool useViewSpaceBox = false;
static bool use2dSampling = false;


// not supported anymore!
static bool fromBoxVisibility = false;


RssPreprocessor::RssPreprocessor():
  mPass(0),
  mVssRays()
{
  // this should increase coherence of the samples
  Environment::GetSingleton()->GetIntValue("RssPreprocessor.samplesPerPass", mSamplesPerPass);
  Environment::GetSingleton()->GetIntValue("RssPreprocessor.initialSamples", mInitialSamples);
  Environment::GetSingleton()->GetIntValue("RssPreprocessor.vssSamples", mRssSamples);
  Environment::GetSingleton()->GetIntValue("RssPreprocessor.vssSamplesPerPass", mRssSamplesPerPass);
  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.useImportanceSampling", mUseImportanceSampling);

  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.Export.pvs", mExportPvs);
  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.Export.rssTree", mExportRssTree);
  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.Export.rays", mExportRays);
  Environment::GetSingleton()->GetIntValue("RssPreprocessor.Export.numRays", mExportNumRays);
  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.useViewcells", mUseViewcells);
  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.objectBasedSampling", mObjectBasedSampling);
  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.directionalSampling", mDirectionalSampling);

  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.loadInitialSamples", mLoadInitialSamples);
  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.storeInitialSamples", mStoreInitialSamples);
  Environment::GetSingleton()->GetBoolValue("RssPreprocessor.updateSubdivision", mUpdateSubdivision);
  
  mStats.open("stats.log");
  mRssTree = NULL;
}


bool
RssPreprocessor::GenerateRays(
                                                          const int number,
                                                          const int sampleType,
                                                          SimpleRayContainer &rays
                                                          )
{
  bool result = false;

  switch (sampleType) {
  case RSS_BASED_DISTRIBUTION:
  case RSS_SILHOUETTE_BASED_DISTRIBUTION:
        if (mRssTree) {
          GenerateImportanceRays(mRssTree, number, rays);
          result = true;
          //      rays.NormalizePdf();
        }
        break;
        
  default:
        result = Preprocessor::GenerateRays(number, sampleType, rays);
  }

  return result;
}

void
RssPreprocessor::CastRays(
                                                  SimpleRayContainer &rays,
                                                  VssRayContainer &vssRays
                                                  )
{
  for (int i=0; i < rays.size(); i++) {
        CastRay(rays[i].mOrigin, rays[i].mDirection, rays[i].mPdf, vssRays);
        if (i % 10000 == 0)
          cout<<".";
  }
  cout<<endl;
}


RssPreprocessor::~RssPreprocessor()
{
  // mVssRays get deleted in the tree
  //  CLEAR_CONTAINER(mVssRays);
}

void
RssPreprocessor::SetupRay(Ray &ray, 
                                                  const Vector3 &point, 
                                                  const Vector3 &direction
                                                  )
{
  ray.intersections.clear();
  // do not store anything else then intersections at the ray
  ray.Init(point, direction, Ray::LOCAL_RAY);
}

int
RssPreprocessor::CastRay(
                                                 Vector3 &viewPoint,
                                                 Vector3 &direction,
                                                 const float probability,
                                                 VssRayContainer &vssRays
                                                 )
{
  int hits = 0;
  static Ray ray;
  AxisAlignedBox3 box = mKdTree->GetBox();

  AxisAlignedBox3 sbox = box;
  sbox.Enlarge(Vector3(-Limits::Small));
  if (!sbox.IsInside(viewPoint))
        return 0;
        
  SetupRay(ray, viewPoint, direction);

  if (!mDetectEmptyViewSpace)
        ray.mFlags &= ~Ray::CULL_BACKFACES;
  else
        ray.mFlags |= Ray::CULL_BACKFACES;


  // cast ray to KD tree to find intersection with other objects
  Intersectable *objectA, *objectB;
  Vector3 pointA, pointB;
  float bsize = Magnitude(box.Size());

  
  if (mKdTree->CastRay(ray)) {
        objectA = ray.intersections[0].mObject;
        pointA = ray.Extrap(ray.intersections[0].mT);
  } else {
        objectA = NULL;
        // compute intersection with the scene bounding box
        float tmin, tmax;
        if (box.ComputeMinMaxT(ray, &tmin, &tmax) && tmin < tmax)
          pointA = ray.Extrap(tmax);
        else
          return 0;
  }


  if (mDetectEmptyViewSpace) {
        SetupRay(ray, pointA, -direction);
  } else
        SetupRay(ray, viewPoint, -direction);
        
  if (!mDetectEmptyViewSpace)
        ray.mFlags &= ~Ray::CULL_BACKFACES;
  else
        ray.mFlags |= Ray::CULL_BACKFACES;

  if (mKdTree->CastRay(ray)) {
        objectB = ray.intersections[0].mObject;
        pointB = ray.Extrap(ray.intersections[0].mT);
  } else {
        objectB = NULL;
        float tmin, tmax;
        if (box.ComputeMinMaxT(ray, &tmin, &tmax) && tmin < tmax)
          pointB = ray.Extrap(tmax);
        else
          return 0;
  }

  //  if (objectA == NULL && objectB != NULL) {
  if (mDetectEmptyViewSpace) {
        // cast again to ensure that there is no objectA
        SetupRay(ray, pointB, direction);
        ray.mFlags |= Ray::CULL_BACKFACES;
        if (mKdTree->CastRay(ray)) {
          objectA = ray.intersections[0].mObject;
          pointA = ray.Extrap(ray.intersections[0].mT);
        }
  }
  
  
  VssRay *vssRay  = NULL;

  bool validSample = (objectA != objectB);
  if (validSample) {
        if (objectA) {
          vssRay = new VssRay(pointB,
                                                  pointA,
                                                  objectB,
                                                  objectA,
                                                  mPass,
                                                  probability
                                                  );
          vssRays.push_back(vssRay);
          hits ++;

        }
        
        if (objectB) {
          vssRay = new VssRay(pointA,
                                                  pointB,
                                                  objectA,
                                                  objectB,
                                                  mPass,
                                                  probability
                                                  );
          vssRays.push_back(vssRay);
          hits ++;
        }
  }
  
  return hits;
}


void
RssPreprocessor::ExportObjectRays(VssRayContainer &rays,
                                                                  const int objectId)
{
  ObjectContainer::const_iterator oi;

  Intersectable *object = NULL;
  for (oi = mObjects.begin(); oi != mObjects.end(); ++oi)
        if (objectId == (*oi)->GetId()) {
          object = *oi;
          break;
        }

  if (object == NULL)
        return;
  
  VssRayContainer selectedRays;
  VssRayContainer::const_iterator it= rays.begin(), it_end = rays.end();

  
  for (; it != it_end; ++it) {
        if ((*it)->mTerminationObject == object)
          selectedRays.push_back(*it);
  }
  

  Exporter *exporter = Exporter::GetExporter("object-rays.x3d");
  //    exporter->SetWireframe();
  //    exporter->ExportKdTree(*mKdTree);
  exporter->SetFilled();
  exporter->ExportIntersectable(object);
  exporter->ExportRays(selectedRays, RgbColor(1, 0, 0));
  
  delete exporter;
  
}


int
RssPreprocessor::GenerateImportanceRays(RssTree *rssTree,
                                                                                const int desiredSamples,
                                                                                SimpleRayContainer &rays
                                                                                )
{
  int num;

  rssTree->UpdateTreeStatistics();

  cout<<
        "#RSS_AVG_PVS_SIZE\n"<<rssTree->stat.avgPvsSize<<endl<<
        "#RSS_AVG_RAYS\n"<<rssTree->stat.avgRays<<endl<<
        "#RSS_AVG_RAY_CONTRIB\n"<<rssTree->stat.avgRayContribution<<endl<<
        "#RSS_AVG_PVS_ENTROPY\n"<<rssTree->stat.avgPvsEntropy<<endl<<
        "#RSS_AVG_RAY_LENGTH_ENTROPY\n"<<rssTree->stat.avgRayLengthEntropy<<endl<<
        "#RSS_AVG_IMPORTANCE\n"<<rssTree->stat.avgImportance<<endl;
  
  if (0) {
        float p = desiredSamples/(float)(rssTree->stat.avgRayContribution*rssTree->stat.Leaves());
        num = rssTree->GenerateRays(p, rays);
  } else {
        int leaves = rssTree->stat.Leaves()/1;
        num = rssTree->GenerateRays(desiredSamples, leaves, rays);
  }
        
        
  return num;
}


bool
RssPreprocessor::ExportRays(const char *filename,
                                                        const VssRayContainer &vssRays,
                                                        const int number
                                                        )
{
  cout<<"Exporting vss rays..."<<endl<<flush;
        
  Exporter *exporter = NULL;
  exporter = Exporter::GetExporter(filename);
  //    exporter->SetWireframe();
  //    exporter->ExportKdTree(*mKdTree);
  exporter->SetFilled();
  // $$JB temporarily do not export the scene
  if (0)
        exporter->ExportScene(mSceneGraph->mRoot);
  exporter->SetWireframe();

  if (mViewSpaceBox) {
        exporter->SetForcedMaterial(RgbColor(1,0,1));
        exporter->ExportBox(*mViewSpaceBox);
        exporter->ResetForcedMaterial();
  }
        
  VssRayContainer rays;
  
  vssRays.SelectRays( number, rays);

  exporter->ExportRays(rays, RgbColor(1, 0, 0));
        
  delete exporter;

  cout<<"done."<<endl<<flush;

  return true;
}


bool
RssPreprocessor::ExportRssTree(char *filename,
                                                           RssTree *tree,
                                                           const Vector3 &dir
                                                           )
{
  Exporter *exporter = Exporter::GetExporter(filename);
  exporter->SetFilled();
  exporter->ExportScene(mSceneGraph->mRoot);
  //  exporter->SetWireframe();
  bool result = exporter->ExportRssTree2( *tree, dir );
  delete exporter;
  return result;
}

bool
RssPreprocessor::ExportRssTreeLeaf(char *filename,
                                                                   RssTree *tree,
                                                                   RssTreeLeaf *leaf)
{
  Exporter *exporter = NULL;
  exporter = Exporter::GetExporter(filename);
  exporter->SetWireframe();
  exporter->ExportKdTree(*mKdTree);
        
  if (mViewSpaceBox) {
        exporter->SetForcedMaterial(RgbColor(1,0,0));
        exporter->ExportBox(*mViewSpaceBox);
        exporter->ResetForcedMaterial();
  }
        
  exporter->SetForcedMaterial(RgbColor(0,0,1));
  exporter->ExportBox(tree->GetBBox(leaf));
  exporter->ResetForcedMaterial();
        
  VssRayContainer rays[4];
  for (int i=0; i < leaf->rays.size(); i++) {
        int k = leaf->rays[i].GetRayClass();
        rays[k].push_back(leaf->rays[i].mRay);
  }
        
  // SOURCE RAY
  exporter->ExportRays(rays[0], RgbColor(1, 0, 0));
  // TERMINATION RAY
  exporter->ExportRays(rays[1], RgbColor(1, 1, 1));
  // PASSING_RAY
  exporter->ExportRays(rays[2], RgbColor(1, 1, 0));
  // CONTAINED_RAY
  exporter->ExportRays(rays[3], RgbColor(0, 0, 1));

  delete exporter;
  return true;
}

void
RssPreprocessor::ExportRssTreeLeaves(RssTree *tree, const int number)
{
  vector<RssTreeLeaf *> leaves;
  tree->CollectLeaves(leaves);

  int num = 0;
  int i;
  float p = number / (float)leaves.size();
  for (i=0; i < leaves.size(); i++) {
        if (RandomValue(0,1) < p) {
          char filename[64];
          sprintf(filename, "rss-leaf-%04d.x3d", num);
          ExportRssTreeLeaf(filename, tree, leaves[i]);
          num++;
        }
        if (num >= number)
          break;
  }
}


float
RssPreprocessor::GetAvgPvsSize(RssTree *tree,
                                                           const vector<AxisAlignedBox3> &viewcells
                                                           )
{
  vector<AxisAlignedBox3>::const_iterator it, it_end = viewcells.end();

  int sum = 0;
  for (it = viewcells.begin(); it != it_end; ++ it)
        sum += tree->GetPvsSize(*it);
        
  return sum/(float)viewcells.size();
}


void
RssPreprocessor::ExportPvs(char *filename,
                                                   RssTree *rssTree
                                                   )
{
  ObjectContainer pvs;
  if (rssTree->CollectRootPvs(pvs)) {
        Exporter *exporter = Exporter::GetExporter(filename);
        exporter->SetFilled();
        exporter->ExportGeometry(pvs);
        exporter->SetWireframe();
        exporter->ExportBox(rssTree->bbox);
        exporter->ExportViewpoint(rssTree->bbox.Center(), Vector3(1,0,0));
        delete exporter;
  }
}


void
RssPreprocessor::ComputeRenderError()
{
  // compute rendering error
  if (renderer && renderer->mPvsStatFrames) {
        //      emit EvalPvsStat();
        //      QMutex mutex;
        //      mutex.lock();
        //      renderer->mRenderingFinished.wait(&mutex);
        //      mutex.unlock();

        renderer->EvalPvsStat();
        mStats <<
          "#AvgPvsRenderError\n" <<renderer->mPvsStat.GetAvgError()<<endl<<
          "#MaxPvsRenderError\n" <<renderer->mPvsStat.GetMaxError()<<endl<<
          "#ErrorFreeFrames\n" <<renderer->mPvsStat.GetErrorFreeFrames()<<endl<<
          "#AvgRenderPvs\n" <<renderer->mPvsStat.GetAvgPvs()<<endl;
  }
}



bool
RssPreprocessor::ComputeVisibility()
{

  Debug << "type: rss" << endl;

  cout<<"Rss Preprocessor started\n"<<flush;
  //  cout<<"Memory/ray "<<sizeof(VssRay)+sizeof(RssTreeNode::RayInfo)<<endl;

  Randomize(0);
  
        
  long startTime = GetTime();
  
  int totalSamples = 0;

  mViewSpaceBox = NULL;

  // if not already loaded, construct view cells from file
  if (!mLoadViewCells) {        

        if (0) 
          mViewCellsManager->SetViewSpaceBox(mKdTree->GetBox());
        else {
          AxisAlignedBox3 box = mKdTree->GetBox();
          float s = box.Size(0);
          box.Scale(0.1f);
          box.SetMin(0, box.Min(0) + s);
          box.SetMax(0, box.Max(0) + s);
         
          mViewCellsManager->SetViewSpaceBox(box);
        }

          // construct view cells using it's own set of samples
          mViewCellsManager->Construct(this);

          //-- several visualizations and statistics
          Debug << "view cells construction finished: " << endl;
          mViewCellsManager->PrintStatistics(Debug);
  }


  int rssPass = 0;
  int rssSamples = 0;
  
  if (mLoadInitialSamples) {
        cout << "Loading samples from file ... ";
        LoadSamples(mVssRays, mObjects);
        cout << "finished\n" << endl;
  } else {
        SimpleRayContainer rays;

        cout<<"Generating initial rays..."<<endl<<flush;

        GenerateRays(mInitialSamples/4, SPATIAL_BOX_BASED_DISTRIBUTION, rays);
        GenerateRays(mInitialSamples/4, OBJECT_BASED_DISTRIBUTION, rays);
        GenerateRays(mInitialSamples/4, DIRECTION_BASED_DISTRIBUTION, rays);
        GenerateRays(mInitialSamples/4, OBJECT_DIRECTION_BASED_DISTRIBUTION, rays);
        
        cout<<"Casting initial rays..."<<endl<<flush;
        CastRays(rays, mVssRays);

        ExportObjectRays(mVssRays, 1546);
  }
  
  cout << "#totalRayStackSize=" << (int)mVssRays.size() << endl <<flush;
  
  rssSamples += (int)mVssRays.size();
  totalSamples += mInitialSamples;
  mPass++;
  
  if (mExportRays) {
        
        char filename[64];
        sprintf(filename, "rss-rays-initial.x3d");
        ExportRays(filename, mVssRays, mExportNumRays);
        
  }
  
  if (mStoreInitialSamples) {
        cout << "Writing samples to file ... ";
        ExportSamples(mVssRays);
        cout << "finished\n" << endl;
  }
        
  if (mUseViewcells) {

        cout<<"Computing sample contributions..."<<endl<<flush;
        // evaluate contributions of the intitial rays
        mViewCellsManager->ComputeSampleContributions(mVssRays, true, false);
        cout<<"done.\n"<<flush;
        
        mStats <<
          "#Pass\n" <<mPass<<endl<<
          "#RssPass\n" <<rssPass<<endl<<
          "#Time\n" << TimeDiff(startTime, GetTime())*1e-3<<endl<<
          "#TotalSamples\n" <<totalSamples<<endl<<
          "#RssSamples\n" <<rssSamples<<endl;

        {
          VssRayContainer contributingRays;
          mVssRays.GetContributingRays(contributingRays, mPass);
          mStats<<"#NUM_CONTRIBUTING_RAYS\n"<<(int)contributingRays.size()<<endl;
        }
        
        mVssRays.PrintStatistics(mStats);
        mViewCellsManager->PrintPvsStatistics(mStats);
          
        // viewcells->UpdatePVS(newVssRays);
        Debug<<"Valid viewcells before set validity: "<<mViewCellsManager->CountValidViewcells()<<endl;
        // cull viewcells with PVS > median (0.5f)
        //mViewCellsManager->SetValidityPercentage(0, 0.5f); 
        mViewCellsManager->SetValidityPercentage(0, 1.0f); 
        Debug<<"Valid viewcells after set validity: "<<mViewCellsManager->CountValidViewcells()<<endl;
        
        ComputeRenderError();
  }
  
  rssPass++;
  
  mRssTree = new RssTree;
  mRssTree->SetPass(mPass);
  
  /// compute view cell contribution of rays if view cells manager already constructed
  //  mViewCellsManager->ComputeSampleContributions(mVssRays, true, false);

  if (mUseImportanceSampling) {
        
        mRssTree->Construct(mObjects, mVssRays);
        
        mRssTree->stat.Print(mStats);
        cout<<"RssTree root PVS size = "<<mRssTree->GetRootPvsSize()<<endl;
        
        if (mExportRssTree) {
          ExportRssTree("rss-tree-100.x3d", mRssTree, Vector3(1,0,0));
          ExportRssTree("rss-tree-001.x3d", mRssTree, Vector3(0,0,1));
          ExportRssTree("rss-tree-101.x3d", mRssTree, Vector3(1,0,1));
          ExportRssTree("rss-tree-101m.x3d", mRssTree, Vector3(-1,0,-1));
          ExportRssTreeLeaves(mRssTree, 10);
        }
        
        if (mExportPvs) {
          ExportPvs("rss-pvs-initial.x3d", mRssTree);
        }
  }
  
  
  while (1) {
        SimpleRayContainer rays;
        VssRayContainer vssRays;
        int castRays = 0;
        if (mUseImportanceSampling) {
          VssRayContainer tmpVssRays;

          float ratios[] = {0.8f,0.1f,0.1f};

          GenerateRays(mRssSamplesPerPass*ratios[0], RSS_BASED_DISTRIBUTION, rays);
          CastRays(rays, tmpVssRays);
          castRays += rays.size();
          float c1 = mViewCellsManager->ComputeSampleContributions(tmpVssRays, false, true);
          mStats<<"#RssRelContrib"<<endl<<c1/rays.size()<<endl;

          vssRays.insert(vssRays.end(), tmpVssRays.begin(), tmpVssRays.end() );
          rays.clear();
          tmpVssRays.clear();

          if (ratios[1]!=0.0f) {
                GenerateRays(mRssSamplesPerPass*ratios[1], SPATIAL_BOX_BASED_DISTRIBUTION, rays);
                CastRays(rays, tmpVssRays);
                castRays += rays.size();
                float c2 = mViewCellsManager->ComputeSampleContributions(tmpVssRays, false, true);
                mStats<<"#SpatialRelContrib"<<endl<<c2/rays.size()<<endl;
                
                vssRays.insert(vssRays.end(), tmpVssRays.begin(), tmpVssRays.end() );
                
                rays.clear();
                tmpVssRays.clear();
          }
          
          
          if (ratios[2]!=0.0f) {
                GenerateRays(mRssSamplesPerPass*ratios[2], DIRECTION_BASED_DISTRIBUTION, rays);
                CastRays(rays, tmpVssRays);
                castRays += rays.size();
                float c3 = mViewCellsManager->ComputeSampleContributions(tmpVssRays, false, true);
                mStats<<"#DirectionalRelContrib"<<endl<<c3/rays.size()<<endl;
                
                vssRays.insert(vssRays.end(), tmpVssRays.begin(), tmpVssRays.end() );
                
                rays.clear();
                tmpVssRays.clear();
          }
          
          // add contributions of all rays at once...
          mViewCellsManager->AddSampleContributions(vssRays);
          
        }
        else {
          int rayType = SPATIAL_BOX_BASED_DISTRIBUTION;
          if (mObjectBasedSampling)
                rayType = OBJECT_BASED_DISTRIBUTION;
          else
                if (mDirectionalSampling)
                  rayType = DIRECTION_BASED_DISTRIBUTION;

          cout<<"Generating rays..."<<endl;

          GenerateRays(mRssSamplesPerPass, rayType, rays);
          cout<<"done."<<endl;

          cout<<"Casting rays..."<<endl;
          CastRays(rays, vssRays);
          cout<<"done."<<endl;
          castRays += rays.size();
          if (mUseViewcells) {
                /// compute view cell contribution of rays
                cout<<"Computing sample contributions..."<<endl;
                mViewCellsManager->ComputeSampleContributions(vssRays, true, false);
                cout<<"done."<<endl;
          }
                
          
        }
        totalSamples += castRays;
        rssSamples += (int)vssRays.size();

        cout<<"Generated "<<castRays<<" rays, progress "<<100.0f*totalSamples/((float) mRssSamples +
                                                                                                                                                   mInitialSamples)<<"%\n";
        
        
        mStats <<
          "#Pass\n" <<mPass<<endl<<
          "#RssPass\n" <<rssPass<<endl<<
          "#Time\n" << TimeDiff(startTime, GetTime())*1e-3<<endl<<
          "#TotalSamples\n" <<totalSamples<<endl<<
          "#RssSamples\n" <<rssSamples<<endl;


        if (mUseViewcells) {
          vssRays.PrintStatistics(mStats);
          mViewCellsManager->PrintPvsStatistics(mStats);
        }

        if (0 && mPass > 0) {
          if (mUseImportanceSampling)
                renderer->mSnapPrefix.sprintf("snap/i-%02d-", mPass);
          else
                renderer->mSnapPrefix.sprintf("snap/r-%02d-", mPass);
          renderer->mSnapErrorFrames = true;
        }

        ComputeRenderError();
        
        // epxort rays before adding them to the tree -> some of them can be deleted

        if (mExportRays) {
          char filename[64];
          if (mUseImportanceSampling)
                sprintf(filename, "rss-rays-i%04d.x3d", rssPass);
          else
                sprintf(filename, "rss-rays-%04d.x3d", rssPass);
          
          ExportRays(filename, vssRays, mExportNumRays);

          // now export all contributing rays
          VssRayContainer contributingRays;
          vssRays.GetContributingRays(contributingRays, mPass);
          mStats<<"#NUM_CONTRIBUTING_RAYS\n"<<(int)contributingRays.size()<<endl;
          sprintf(filename, "rss-crays-%04d.x3d", rssPass);
          ExportRays(filename, contributingRays, mExportNumRays);
        }

        
        // add rays to the tree after the viewcells have been cast to have their contributions
        // already when adding into the tree
        // do not add those rays which have too low or no contribution....
        
        if (mUseImportanceSampling) {
          mRssTree->AddRays(vssRays);
          
          if (mUpdateSubdivision) {
                int updatePasses = 1;
                if (mPass % updatePasses == 0) {
                  int subdivided = mRssTree->UpdateSubdivision();
                  cout<<"subdivided leafs = "<<subdivided<<endl;
                  cout<<"#total leaves = "<<mRssTree->stat.Leaves()<<endl;
                }
          }
        }
        
        if (mExportPvs) {
          char filename[64];
          sprintf(filename, "rss-pvs-%04d.x3d", rssPass);
          ExportPvs(filename, mRssTree);
        }
        
        
        if (!mUseImportanceSampling) 
          CLEAR_CONTAINER(vssRays);
        // otherwise the rays get deleted by the rss tree update according to RssTree.maxRays ....

        if (totalSamples >= mRssSamples + mInitialSamples)
          break;

        
        rssPass++;
        mPass++;
        mRssTree->SetPass(mPass);
  }
  
  if (mUseViewcells) {

          if(0)
          {
                  VssRayContainer selectedRays;
                  int desired = mViewCellsManager->GetVisualizationSamples();

                  mVssRays.SelectRays(desired, selectedRays);

                  mViewCellsManager->Visualize(mObjects, selectedRays);
          }
          
          // view cells after sampling
          mViewCellsManager->PrintStatistics(Debug);
      
          //-- render simulation after merge
          cout << "\nevaluating bsp view cells render time after sampling ... ";
          
          mRenderSimulator->RenderScene();
          SimulationStatistics ss;
          mRenderSimulator->GetStatistics(ss);
          
          cout << " finished" << endl;
          cout << ss << endl;
          Debug << ss << endl;
        
  }
  
  Debug<<"Deleting RSS tree...\n";
  delete mRssTree;
  Debug<<"Done.\n";


  //  mViewCellsManager->ExportViewCells("visibility.xml",
  //                                                                     true);
  
  
  return true;
}

}