source: trunk/VUT/GtpVisibilityPreprocessor/src/SamplingPreprocessor.cpp @ 223

#include "SceneGraph.h"
#include "KdTree.h"
#include "SamplingPreprocessor.h"
#include "X3dExporter.h"
#include "Environment.h"
#include "MutualVisibility.h"

SamplingPreprocessor::SamplingPreprocessor()
{
  // this should increase coherence of the samples
  environment->GetIntValue("Sampling.samplesPerPass", mSamplesPerPass);
  environment->GetIntValue("Sampling.totalSamples", mTotalSamples);
  mKdPvsDepth = 100;

}

void
SamplingPreprocessor::SetupRay(Ray &ray, const Vector3 &point, const Vector3 &direction)
{
  ray.intersections.clear();
  ray.leaves.clear();
  ray.meshes.clear();
  //  cout<<point<<" "<<direction<<endl;
  ray.Init(point, direction, Ray::LOCAL_RAY);
}

KdNode *
SamplingPreprocessor::GetNodeForPvs(KdLeaf *leaf)
{
  KdNode *node = leaf;
  while (node->mParent && node->mDepth > mKdPvsDepth)
    node = node->mParent;
  return node;
}

int
SamplingPreprocessor::AddNodeSamples(Intersectable *object,
                                     const Ray &ray,
                                     const int pass)
{
  int contributingSamples = 0;
  int j;
  for (j=0; j < ray.leaves.size(); j++) {
    KdNode *node = GetNodeForPvs( ray.leaves[j] );
    contributingSamples += object->mKdPvs.AddNodeSample(node);
  }
  
  if (pass > 10)
    for (j=1; j < ray.leaves.size() - 1; j++) {
      ray.leaves[j]->AddPassingRay(ray, contributingSamples ? 1 : 0);
    }
  
  return contributingSamples;
}


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;
  }
}

bool
SamplingPreprocessor::ComputeVisibility()
{

  // pickup an object
  ObjectContainer objects;
  
  mSceneGraph->CollectObjects(&objects);

  Vector3 point, normal, direction;
  Ray ray;

  long startTime = GetTime();
  
  int i;
  int pass = 0;
  int totalSamples = 0;

  int pvsOut = Min((int)objects.size(), 10);
  
  vector<Ray> rays[10];
  
  while (totalSamples < mTotalSamples)
    {
      int passContributingSamples = 0;
      int passSampleContributions = 0;
      int passSamples = 0;
      int index = 0;

      for (i =0; i < objects.size(); i++) {
        KdNode *nodeToSample = NULL;
        Intersectable *object = objects[i];
                  
        int pvsSize = object->mKdPvs.GetSize();
      
        if (0 && pvsSize) {
          // 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();
          }

          int maxTries = 2*pvsSize;
        
          for (int tries = 0; tries < 10; tries++) {
            index = RandomValue(0, pvsSize - 1);
            KdPvsData data;
            KdNode *node;
            object->mKdPvs.GetData(index, node, data);
            nodeToSample = mKdTree->FindRandomNeighbor(node, true);
            if (nodeToSample)
              break;
          }
        }

        
        if (pvsSize && pass == 50 ) {
          // 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();
          }
        
          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(mKdTree,
                                                    box,
                                                    mKdTree->GetBox(invisibleNeighbors[j]),
                                                    1.0f);
            
            }
            // now rank all the neighbors according to probability that a new
            // sample creates some contribution
          }
        }

      
        for (int k=0; k < mSamplesPerPass; k++) {
          object->GetRandomSurfacePoint(point, normal);
        
          if (nodeToSample) {
            int maxTries = 5;
          
            for (int tries = 0; tries < maxTries; tries++) {
              direction = mKdTree->GetBox(nodeToSample).GetRandomPoint() - point;
            
              if (DotProd(direction, normal) > Limits::Small)
                break;
            }
          
            if (tries == maxTries)
              direction = UniformRandomVector(normal);
          } 
          else
            direction = UniformRandomVector(normal);
        
          // construct a ray
          SetupRay(ray, point, direction);
          mKdTree->CastRay(ray);

          if (i < pvsOut)
            rays[i].push_back(ray);
        
          int sampleContributions = 0;
        
                  
          if (ray.leaves.size()) {
            sampleContributions += AddNodeSamples(object, ray, pass);
          
            if (ray.intersections.size()) {
              sampleContributions += AddNodeSamples(ray.intersections[0].mObject, ray, pass);
              // check whether we can add this to the rays
              for (int j = 0; j < pvsOut; j++) {
                if (objects[j] == ray.intersections[0].mObject) {
                  rays[j].push_back(ray);
                }
              }
            }

            passSamples++;
                        
            if (sampleContributions) {
              passContributingSamples++;
              passSampleContributions += sampleContributions;
            }
          }
        }
      }

      totalSamples += passSamples;

      //    if (pass>10)
      //      HoleSamplingPass();
    

      pass++;
    
      int pvsSize = 0;
      for (i=0; i < objects.size(); i++) {
        Intersectable *object = objects[i];
        pvsSize += object->mKdPvs.GetSize();
      }
    
      cout << "pass " << pass<<" : t = " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
      cout << "#totalSamples=" << totalSamples/1000 
           << "k   #sampleContributions=" << passSampleContributions << " (" 
           << 100*passContributingSamples/(float)passSamples<<"%)" << " avgPVS="
           << pvsSize/(float)objects.size() << endl 
           << "avg ray contrib=" << passSampleContributions/(float)passContributingSamples << endl;
    }

  int totalPvsSize = mKdTree->CollectLeafPvs();
  cout << "#totalPvsSize=" << totalPvsSize << endl;
  
  //  HoleSamplingPass();
  if (1) {
    Exporter *exporter = Exporter::GetExporter("ray-density.x3d");
    exporter->SetExportRayDensity(true);
    exporter->ExportKdTree(*mKdTree);
    delete exporter;
  }
  
  bool exportRays = false;
  if (exportRays) {
    Exporter *exporter = NULL;
    exporter = Exporter::GetExporter("sample-rays.x3d");
    exporter->SetWireframe();
    exporter->ExportKdTree(*mKdTree);

    for (i=0; i < pvsOut; i++) 
      exporter->ExportRays(rays[i], 1000, RgbColor(1, 0, 0));
    exporter->SetFilled();
          
    delete exporter;
  }

  if (1) {
    for (int k=0; k < pvsOut; k++) {
      Intersectable *object = objects[k];
      char s[64];
      sprintf(s, "sample-pvs%04d.x3d", k);
      Exporter *exporter = Exporter::GetExporter(s);
      exporter->SetWireframe();
      KdPvsMap::iterator i = object->mKdPvs.mEntries.begin();
                  
      Intersectable::NewMail();
                  
      // avoid adding the object to the list
      object->Mail();
      ObjectContainer visibleObjects;
      for (; i != object->mKdPvs.mEntries.end(); i++) {
        KdNode *node = (*i).first;
        exporter->ExportBox(mKdTree->GetBox(node));
        mKdTree->CollectObjects(node, visibleObjects);
      }
      
      exporter->ExportRays(rays[k], 1000, RgbColor(0, 1, 0));
      exporter->SetFilled();

      for (int j = 0; j < visibleObjects.size(); j++)
        exporter->ExportIntersectable(visibleObjects[j]);
        
      Material m;
      m.mDiffuseColor = RgbColor(1, 0, 0);
      exporter->SetForcedMaterial(m);
      exporter->ExportIntersectable(object);
      
      delete exporter;
    }
  }
  
  return true;
}