source: GTP/trunk/Lib/Vis/Preprocessing/src/SamplingPreprocessor.cpp @ 1251

#include "SceneGraph.h"
#include "KdTree.h"
#include "SamplingPreprocessor.h"
#include "X3dExporter.h"
#include "Environment.h"
#include "MutualVisibility.h"
#include "Polygon3.h"
#include "ViewCell.h"
#include "ViewCellsManager.h"
#include "RenderSimulator.h"



namespace GtpVisibilityPreprocessor {


SamplingPreprocessor::SamplingPreprocessor(): mPass(0)
{
  // this should increase coherence of the samples
  Environment::GetSingleton()->GetIntValue("SamplingPreprocessor.samplesPerPass", mSamplesPerPass);
  Environment::GetSingleton()->GetIntValue("SamplingPreprocessor.totalSamples", mTotalSamples);
  
  mStats.open("stats.log");
}

SamplingPreprocessor::~SamplingPreprocessor()
{
  CLEAR_CONTAINER(mSampleRays);
  CLEAR_CONTAINER(mVssSampleRays);
}

Intersectable *
SamplingPreprocessor::CastRay(
                                                          const Vector3 &origin,
                                                          const Vector3 &direction
                                                          )
{
  static Ray ray;
  AxisAlignedBox3 box = mViewCellsManager->GetViewSpaceBox();
  
  AxisAlignedBox3 sbox = box;
  sbox.Enlarge(Vector3(-Limits::Small));
  if (!sbox.IsInside(origin))
        return 0;
        
  ray.intersections.clear();
  // do not store anything else then intersections at the ray
  ray.Init(origin, direction, Ray::LOCAL_RAY);

  ray.mFlags &= ~Ray::CULL_BACKFACES;



  // cast ray to KD tree to find intersection with other objects
  Intersectable *objectA = NULL;
  Vector3 pointA;
  float bsize = Magnitude(box.Size());
  
  if (mKdTree->CastRay(ray)) {
        if (!mDetectEmptyViewSpace || DotProd(ray.intersections[0].mNormal, direction) < 0) {
          objectA = ray.intersections[0].mObject;
          pointA = ray.Extrap(ray.intersections[0].mT);
        }
  }
  return objectA;
}

void
SamplingPreprocessor::HoleSamplingPass()
{
  vector<KdLeaf *> leaves;
  mKdTree->CollectLeaves(leaves);
  
  // go through all the leaves and evaluate their passing contribution
  for (int i=0 ; i < leaves.size(); i++) {
    KdLeaf *leaf = leaves[i];
    cout<<leaf->mPassingRays<<endl;
  }
}


void
SamplingPreprocessor::VerifyVisibility(Intersectable *object)
{
        // mail all nodes from the pvs
  Intersectable::NewMail();
  KdPvsMap::iterator i = object->mKdPvs.mEntries.begin();
  for (; i != object->mKdPvs.mEntries.end(); i++) {
        KdNode *node = (*i).first;
        node->Mail();
  }
  Debug << "Get all neighbours from PVS" << endl;
  vector<KdNode *> invisibleNeighbors;
  // get all neighbors of all PVS nodes
  i = object->mKdPvs.mEntries.begin();
  for (; i != object->mKdPvs.mEntries.end(); i++) {
        KdNode *node = (*i).first;
        mKdTree->FindNeighbors(node, invisibleNeighbors, true);
        AxisAlignedBox3 box = object->GetBox();
        for (int j=0; j < invisibleNeighbors.size(); j++) {
          int visibility = ComputeBoxVisibility(mSceneGraph,
                                                                                        mKdTree,
                                                                                        box,
                                                                                        mKdTree->GetBox(invisibleNeighbors[j]),
                                                                                        1e-6f);
          //          exit(0);
        }
        // now rank all the neighbors according to probability that a new
        // sample creates some contribution
  }
}

bool
SamplingPreprocessor::ComputeVisibility()
{
  
  Debug << "type: sampling" << endl;
  
  cout<<"Sampling Preprocessor started\n"<<flush;
  //  cout<<"Memory/ray "<<sizeof(VssRay)+sizeof(RssTreeNode::RayInfo)<<endl;

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

  // if not already loaded, construct view cells from file
  if (!mLoadViewCells)
  {
        mViewCellsManager->SetViewSpaceBox(mKdTree->GetBox());

        // 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 samples = 0;
  int i=0;
  while (samples < mTotalSamples) {
        for (i=0; i < mSamplesPerPass; i++, samples++) {
          
          if (i%10000 == 0)
                cout<<"+";
          
          Vector3 origin, direction;
          mViewCellsManager->GetViewPoint(origin);
          direction = UniformRandomVector();

          
          ViewCell *viewcell = mViewCellsManager->GetViewCell(origin);
          
          if (viewcell && viewcell->GetValid()) {
                // cast rays in both directions to make the number of samples comparable
                // with the global sampling method which also casts a "double" ray per sample
                for (int j=0; j < 2; j++) {
                  Intersectable *object = CastRay(origin, direction);
                  if (object) {
                        // if ray not outside of view space
                        float contribution;
                        int pvsContribution = 0;
                        float relativePvsContribution = 0;
                        if (object) {
                          float pdf = 1.0f;
                          if (viewcell->GetPvs().GetSampleContribution(object,
                                                                                                                   pdf,
                                                                                                                   contribution))
                                ++pvsContribution;
                          relativePvsContribution += contribution;
                          viewcell->GetPvs().AddSample(object, pdf);
                        }
                  }
                  direction = -direction;
                }
          }
          
          if (samples > mTotalSamples)
                break;
        }
        
        //      mVssRays.PrintStatistics(mStats);
        mStats <<
          "#Time\n" << TimeDiff(startTime, GetTime())*1e-3<<endl<<
          "#TotalSamples\n" <<samples<<endl;

        mViewCellsManager->PrintPvsStatistics(mStats);
        // ComputeRenderError();
  }
  
  //  HoleSamplingPass();
        if (0) {
          Exporter *exporter = Exporter::GetExporter("ray-density.x3d"); 
          exporter->SetExportRayDensity(true);
          exporter->ExportKdTree(*mKdTree);
          delete exporter;
        }
        
        
        // $$JB temporary removed
        //      mViewCellsManager->PostProcess(objects, mSampleRays);
        
        //-- several visualizations and statistics
        Debug << "view cells after post processing: " << endl;
        mViewCellsManager->PrintStatistics(Debug);
        
        //-- render simulation after merge
        cout << "\nevaluating bsp view cells render time after merge ... ";
        
        mRenderSimulator->RenderScene();
        SimulationStatistics ss;
        mRenderSimulator->GetStatistics(ss);
        
        cout << " finished" << endl;
        cout << ss << endl;
        Debug << ss << endl;
        
        // $$JB temporary removed
        //mViewCellsManager->Visualize(objects, mSampleRays);   
        
        return true;
}


}