Float Camera::GenerateRayDifferential(const CameraSample &sample,
RayDifferential *rd) const {
Float wt = GenerateRay(sample, rd);
// Find camera ray after shifting one pixel in the $x$ direction
CameraSample sshift = sample;
sshift.pFilm.x++;
Ray rx;
Float wtx = GenerateRay(sshift, &rx);
if (wtx == 0) return 0;
rd->rxOrigin = rx.o;
rd->rxDirection = rx.d;
// Find camera ray after shifting one pixel in the $y$ direction
sshift.pFilm.x--;
sshift.pFilm.y++;
Ray ry;
Float wty = GenerateRay(sshift, &ry);
if (wty == 0) return 0;
rd->ryOrigin = ry.o;
rd->ryDirection = ry.d;
rd->hasDifferentials = true;
return wt;
}
//ray tracing
void CPURayTracer::RayTrace()
{
//reset the timer
m_Timer.Reset();
//start the timer
m_Timer.Start();
//bind the buffer
BindBuffer();
for( int j = m_iImageHeight - 1 ; j > -1 ; j-- )
{
for( int i = 0 ; i < m_iImageWidth; i++ )
{
//current index
int currentIndex = j * m_iImageWidth + i;
//current ray
_float4 dir , ori;
//generate a ray for current pixel
GenerateRay( i , j , &ori , &dir );
//copy the image
m_pImageBackBuffer[ currentIndex ] = Trace( ori , dir );
//copy the image
m_pImageBuffer[ currentIndex ] = RGB_FLOAT4( m_pImageBackBuffer[ currentIndex ] );
//update current pixel number
m_iCurrentPixelNum++;
if( m_bForceStop )
break;
}
if( m_bForceStop )
break;
}
//clear the noise
ClearNoise( m_pImageBackBuffer );
//end the timer
m_Timer.Stop();
m_ElapsedTime = (int)m_Timer.GetElapsedTime();
}
void FattalCPU::ComputePropagation( int idPropagation, bool fristSweep, int writeUId )
{
//FIXME: Warning: Handle only cube volume
// Pour chaque elements de la LPM
#pragma omp parallel for
for (short x = 0; x < m_media->Size.x; x++)
{
for (short y = 0; y < m_media->Size.x; y++)
{
for (unsigned short idRay = 0; idRay < NbSamples*NbSamples; idRay++)
{
// Generate Ray
Ray r;
GenerateRay(r,x,y,idRay,Factor,NbSamples, idPropagation);
// Initialize Ray value
r.Position += r.Direction*0.001f;
SPECTRUM rayValue = SPECTRUM_INIT(0.f);
if(fristSweep) {
// FIXME: Add ligthing method
/*if(idPropagation == 1)
rayValue = 40.f/81;*/
rayValue = m_light->getRadiance(idPropagation,x,y,idRay,NbSamples);
}
// Prepare other data
float maxDirectionCoord = std::max(abs(r.Direction.x),std::max(abs(r.Direction.y),abs(r.Direction.z)));
int nbElements = m_media->Size.x*m_media->Size.y*m_media->Size.y;
////////////////////////////////
// Loop (Ray martching )
////////////////////////////////
TraversingVolumeAlgorithm rayTraversing(r);
glm::ivec3 oldCurrendVoxID;
do
{
while(isInGrid(rayTraversing.voxID, m_media->Size.x))
{
//std::cout << rayTraversing.voxID.x << "x" << rayTraversing.voxID.y << "x" << rayTraversing.voxID.z << std::endl;
oldCurrendVoxID = rayTraversing.voxID;
rayTraversing.Traverse(r);
// Je sais que c'est dans la grille
// Car tout les points initialisee sont dedant
int indiceVox = (oldCurrendVoxID.z*m_media->Size.x + oldCurrendVoxID.y)*m_media->Size.x + oldCurrendVoxID.x;
float density = m_media->Density[indiceVox];
if(density > 0.000001)
{
// Calcul de la valeur
SPECTRUM scatteringTerm = rayValue*(1 - exp(-1*m_media->ScatteringCoeff*density*rayTraversing.DeltaLength/maxDirectionCoord)); //
float extinctionCoeff = (m_media->ScatteringCoeff+m_media->AbsorptionCoeff)*density;
float extinctionFactor = exp(-1*extinctionCoeff*rayTraversing.DeltaLength/maxDirectionCoord);
SPECTRUM UValue = m_Us[(writeUId+1)%2][idPropagation*nbElements + indiceVox];
rayValue = rayValue*extinctionFactor+(UValue*(1 - extinctionFactor)/extinctionCoeff);
SPECTRUM value = scatteringTerm;
// TODO: nbRays
// TODO: Cell dim
value *= 1.f / (NbSamples*NbSamples);
#pragma omp critical
{
// Update I
m_I[indiceVox] += value;
for (int k = 0; k < 6; k++ )
{
m_Us[writeUId][k*nbElements + indiceVox] += value / (SPECTRUM)6.f;
}
}
}
}
rayTraversing.wrapCurrentVoxID(m_media->Size.x);
rayValue = SPECTRUM_INIT(0.f);
}
while(isInGrid(rayTraversing.voxID, m_media->Size.x));
} // End For rayID
} // End for Y
} // End for X
}
Ray PinholeLens::GenerateRay(const Vec2f& uv, const Vec2f& auv, float time) {
return GenerateRay(uv,time);
}
