static void
tcoord_to_pcoord(struct vec3 * pcoord, float x, float y, mat4x4 * M)
{
vec4 tc, pc;
tc.x = x;
tc.y = y;
tc.z = 1.0;
tc.w = 0.0;
mulmv(&pc, M, &tc);
pcoord->x = pc.x;
pcoord->y = pc.y;
pcoord->z = pc.z;
TRACE(OPENGL, "tcoord (%f, %f) to pcoord (%f, %f, %f)\n",
x, y, pcoord->x, pcoord->y, pcoord->z);
}
///////////////////////////////////////////////////////////////////////
// Class : CIrradianceCache
// Method : sample
// Description : Sample the occlusion
// Return Value :
// Comments :
void CIrradianceCache::sample(float *C,const float *P,const float *dPdu,const float *dPdv,const float *N,CShadingContext *context) {
CCacheSample *cSample;
int i,j;
float coverage;
vector irradiance;
vector envdir;
float rMean;
CRay ray;
vector X,Y;
CCacheNode *cNode;
int depth;
// Allocate memory
const CShadingScratch *scratch = &(context->currentShadingState->scratch);
const int nt = (int) (sqrtf(scratch->traceParams.samples / (float) C_PI) + 0.5);
const int np = (int) (C_PI*nt + 0.5);
const int numSamples = nt*np;
CHemisphereSample *hemisphere = (CHemisphereSample *) alloca(numSamples*sizeof(CHemisphereSample));
// initialize texture lookups if needed
if (scratch->occlusionParams.environment) {
CTextureLookup::staticInit(&(context->currentShadingState->scratch));
}
// Create an orthanormal coordinate system
if (dotvv(dPdu,dPdu) > 0) {
normalizevf(X,dPdu);
crossvv(Y,N,X);
} else if (dotvv(dPdv,dPdv) > 0) {
normalizevf(X,dPdv);
crossvv(Y,N,X);
} else {
// At this point, we're pretty screwed, so why not use the P
normalizevf(X,P);
crossvv(Y,N,X);
}
// Sample the hemisphere
coverage = 0;
initv(irradiance,0);
initv(envdir,0);
rMean = C_INFINITY;
// Calculate the ray differentials (use average spread in theta and phi)
const float da = tanf((float) C_PI/(2*(nt+np)));
const float db = (lengthv(dPdu) + lengthv(dPdv))*0.5f;
if (scratch->occlusionParams.occlusion == TRUE) {
// We're shading for occlusion
context->numOcclusionRays += numSamples;
context->numOcclusionSamples++;
for (i=0;i<nt;i++) {
for (j=0;j<np;j++,hemisphere++) {
float rv[2];
context->random2d.get(rv);
float tmp = sqrtf((i+context->urand()) / (float) nt);
const float phi = (float) (2*C_PI*(j+context->urand()) / (float) np);
const float cosPhi = (cosf(phi)*tmp);
const float sinPhi = (sinf(phi)*tmp);
tmp = sqrtf(1 - tmp*tmp);
ray.dir[0] = X[0]*cosPhi + Y[0]*sinPhi + N[0]*tmp;
ray.dir[1] = X[1]*cosPhi + Y[1]*sinPhi + N[1]*tmp;
ray.dir[2] = X[2]*cosPhi + Y[2]*sinPhi + N[2]*tmp;
const float originJitterX = (rv[0] - 0.5f)*scratch->traceParams.sampleBase;
const float originJitterY = (rv[1] - 0.5f)*scratch->traceParams.sampleBase;
ray.from[COMP_X] = P[COMP_X] + originJitterX*dPdu[0] + originJitterY*dPdv[0];
ray.from[COMP_Y] = P[COMP_Y] + originJitterX*dPdu[1] + originJitterY*dPdv[1];
ray.from[COMP_Z] = P[COMP_Z] + originJitterX*dPdu[2] + originJitterY*dPdv[2];
ray.flags = ATTRIBUTES_FLAGS_DIFFUSE_VISIBLE;
ray.tmin = scratch->traceParams.bias;
ray.t = scratch->traceParams.maxDist;
ray.time = 0;
ray.da = da;
ray.db = db;
// Transform the ray into the right coordinate system
mulmp(ray.from,from,ray.from);
mulmv(ray.dir,from,ray.dir);
context->trace(&ray);
// Do we have an intersection ?
if (ray.object != NULL) {
const float *color = ray.object->attributes->surfaceColor;
// Yes
coverage++;
addvv(irradiance,color);
hemisphere->coverage = 1;
initv(hemisphere->envdir,0);
movvv(hemisphere->irradiance,color);
} else {
// No
hemisphere->coverage = 0;
addvv(envdir,ray.dir);
movvv(hemisphere->envdir,ray.dir);
// GSH : Texture lookup for misses
if(scratch->occlusionParams.environment != NULL){
CEnvironment *tex = scratch->occlusionParams.environment;
vector D0,D1,D2,D3;
vector color;
// GSHTODO: Add in the dCosPhi and dSinPhi
movvv(D0,ray.dir);
movvv(D1,ray.dir);
movvv(D2,ray.dir);
movvv(D3,ray.dir);
float savedSamples = scratch->traceParams.samples;
context->currentShadingState->scratch.traceParams.samples = 1;
tex->lookup(color,D0,D1,D2,D3,context);
context->currentShadingState->scratch.traceParams.samples = savedSamples;
addvv(irradiance,color);
movvv(hemisphere->irradiance,color);
} else{
initv(hemisphere->irradiance,0);
}
}
hemisphere->depth = ray.t;
hemisphere->invDepth = 1 / ray.t;
if (tmp > horizonCutoff) rMean = min(rMean,ray.t);
movvv(hemisphere->dir,ray.dir);
assert(hemisphere->invDepth > 0);
}
}
} else {
// We're shading for indirectdiffuse
context->numIndirectDiffuseRays += numSamples;
context->numIndirectDiffuseSamples++;
for (i=0;i<nt;i++) {
for (j=0;j<np;j++,hemisphere++) {
float rv[2];
context->random2d.get(rv);
float tmp = sqrtf((i+context->urand()) / (float) nt);
const float phi = (float) (2*C_PI*(j+context->urand()) / (float) np);
const float cosPhi = (cosf(phi)*tmp);
const float sinPhi = (sinf(phi)*tmp);
tmp = sqrtf(1 - tmp*tmp);
ray.dir[0] = X[0]*cosPhi + Y[0]*sinPhi + N[0]*tmp;
ray.dir[1] = X[1]*cosPhi + Y[1]*sinPhi + N[1]*tmp;
ray.dir[2] = X[2]*cosPhi + Y[2]*sinPhi + N[2]*tmp;
const float originJitterX = (rv[0] - 0.5f)*scratch->traceParams.sampleBase;
const float originJitterY = (rv[1] - 0.5f)*scratch->traceParams.sampleBase;
ray.from[COMP_X] = P[COMP_X] + originJitterX*dPdu[0] + originJitterY*dPdv[0];
ray.from[COMP_Y] = P[COMP_Y] + originJitterX*dPdu[1] + originJitterY*dPdv[1];
ray.from[COMP_Z] = P[COMP_Z] + originJitterX*dPdu[2] + originJitterY*dPdv[2];
ray.flags = ATTRIBUTES_FLAGS_DIFFUSE_VISIBLE;
ray.tmin = scratch->traceParams.bias;
ray.t = scratch->traceParams.maxDist;
ray.time = 0;
ray.da = da;
ray.db = db;
// Transform the ray into the right coordinate system
mulmp(ray.from,from,ray.from);
mulmv(ray.dir,from,ray.dir);
context->trace(&ray);
// Do we have an intersection ?
if (ray.object != NULL) {
vector P,N,C;
CAttributes *attributes = ray.object->attributes;
CPhotonMap *globalMap;
if ((globalMap = attributes->globalMap) != NULL) {
normalizev(N,ray.N);
mulvf(P,ray.dir,ray.t);
addvv(P,ray.from);
if(dotvv(ray.dir,N) > 0)
mulvf(N,-1);
globalMap->lookup(C,P,N,attributes->photonEstimator);
// HACK: Avoid too bright spots
tmp = max(max(C[0],C[1]),C[2]);
if (tmp > scratch->occlusionParams.maxBrightness) mulvf(C,scratch->occlusionParams.maxBrightness/tmp);
mulvv(C,attributes->surfaceColor);
addvv(irradiance,C);
movvv(hemisphere->irradiance,C);
context->numIndirectDiffusePhotonmapLookups++;
} else {
initv(hemisphere->irradiance,0);
}
// Yes
coverage++;
hemisphere->coverage = 1;
initv(hemisphere->envdir,0);
} else {
// No
hemisphere->coverage = 0;
addvv(envdir,ray.dir);
movvv(hemisphere->envdir,ray.dir);
// GSH : Texture lookup for misses
if(scratch->occlusionParams.environment != NULL){
CEnvironment *tex = scratch->occlusionParams.environment;
vector D0,D1,D2,D3;
vector color;
// GSHTODO: Add in the dCosPhi and dSinPhi
movvv(D0,ray.dir);
movvv(D1,ray.dir);
movvv(D2,ray.dir);
movvv(D3,ray.dir);
float savedSamples = scratch->traceParams.samples;
context->currentShadingState->scratch.traceParams.samples = 1;
tex->lookup(color,D0,D1,D2,D3,context);
context->currentShadingState->scratch.traceParams.samples = savedSamples;
addvv(irradiance,color);
movvv(hemisphere->irradiance,color);
} else{
movvv(hemisphere->irradiance,scratch->occlusionParams.environmentColor);
addvv(irradiance,scratch->occlusionParams.environmentColor);
}
}
hemisphere->depth = ray.t;
hemisphere->invDepth = 1 / ray.t;
if (tmp > horizonCutoff) rMean = min(rMean,ray.t);
movvv(hemisphere->dir,ray.dir);
assert(hemisphere->invDepth > 0);
}
}
}
hemisphere -= np*nt;
// Normalize
const float tmp = 1 / (float) numSamples;
coverage *= tmp;
mulvf(irradiance,tmp);
normalizevf(envdir);
// Record the value
C[0] = irradiance[0];
C[1] = irradiance[1];
C[2] = irradiance[2];
C[3] = coverage;
C[4] = envdir[0];
C[5] = envdir[1];
C[6] = envdir[2];
// Should we save it ?
if ((scratch->occlusionParams.maxError != 0) && (coverage < 1-C_EPSILON)) {
// We're modifying, lock the thing
osLock(mutex);
// Create the sample
cSample = (CCacheSample *) memory->alloc(sizeof(CCacheSample));
// Compute the gradients of the illumination
posGradient(cSample->gP,np,nt,hemisphere,X,Y);
rotGradient(cSample->gR,np,nt,hemisphere,X,Y);
// Compute the radius of validity
rMean *= 0.5f;
// Clamp the radius of validity
rMean = min(rMean,db*scratch->occlusionParams.maxPixelDist);
// Record the data (in the target coordinate system)
movvv(cSample->P,P);
movvv(cSample->N,N);
cSample->dP = rMean;
cSample->coverage = coverage;
movvv(cSample->envdir,envdir);
movvv(cSample->irradiance,irradiance);
// Do the neighbour clamping trick
clamp(cSample);
rMean = cSample->dP; // copy dP back so we get the right place in the octree
// The error multiplier
const float K = 0.4f / scratch->occlusionParams.maxError;
rMean /= K;
// Insert the new sample into the cache
cNode = root;
depth = 0;
while(cNode->side > (2*rMean)) {
depth++;
for (j=0,i=0;i<3;i++) {
if (P[i] > cNode->center[i]) {
j |= 1 << i;
}
}
if (cNode->children[j] == NULL) {
CCacheNode *nNode = (CCacheNode *) memory->alloc(sizeof(CCacheNode));
for (i=0;i<3;i++) {
if (P[i] > cNode->center[i]) {
nNode->center[i] = cNode->center[i] + cNode->side*0.25f;
} else {
nNode->center[i] = cNode->center[i] - cNode->side*0.25f;
}
}
cNode->children[j] = nNode;
nNode->side = cNode->side*0.5f;
nNode->samples = NULL;
for (i=0;i<8;i++) nNode->children[i] = NULL;
}
cNode = cNode->children[j];
}
cSample->next = cNode->samples;
cNode->samples = cSample;
maxDepth = max(depth,maxDepth);
osUnlock(mutex);
}
}
///////////////////////////////////////////////////////////////////////
// Class : CIrradianceCache
// Method : lookup
// Description : Lookup da cache
// Return Value :
// Comments :
void CIrradianceCache::lookup(float *C,const float *cP,const float *cdPdu,const float *cdPdv,const float *cN,CShadingContext *context) {
const CShadingScratch *scratch = &(context->currentShadingState->scratch);
// Is this a point based lookup?
if ((scratch->occlusionParams.pointbased) && (scratch->occlusionParams.pointHierarchy != NULL)) {
int i;
for (i=0;i<7;i++) C[i] = 0;
scratch->occlusionParams.pointHierarchy->lookup(C,cP,cdPdu,cdPdv,cN,context);
} else {
CCacheSample *cSample;
CCacheNode *cNode;
float totalWeight = 0;
CCacheNode **stackBase = (CCacheNode **) alloca(maxDepth*sizeof(CCacheNode *)*8);
CCacheNode **stack;
int i;
float coverage;
vector irradiance,envdir;
vector P,N;
// A small value for discard-smoothing of irradiance
const float smallSampleWeight = (flags & CACHE_SAMPLE) ? 0.1f : 0.0f;
// Transform the lookup point to the correct coordinate system
mulmp(P,to,cP);
mulmn(N,from,cN);
// Init the result
coverage = 0;
initv(irradiance,0);
initv(envdir,0);
// The weighting algorithm is that described in [Tabellion and Lamorlette 2004]
// We need to convert the max error as in Wald to Tabellion
// The default value of maxError is 0.4f
const float K = 0.4f / scratch->occlusionParams.maxError;
// Note, we do not need to lock the data for reading
// if word-writes are atomic
// Prepare for the non recursive tree traversal
stack = stackBase;
*stack++ = root;
while(stack > stackBase) {
cNode = *(--stack);
// Sum the values in this level
for (cSample=cNode->samples;cSample!=NULL;cSample=cSample->next) {
vector D;
// D = vector from sample to query point
subvv(D,P,cSample->P);
// Ignore sample in the front
float a = dotvv(D,cSample->N);
if ((a*a / (dotvv(D,D) + C_EPSILON)) > 0.1) continue;
// Positional error
float e1 = sqrtf(dotvv(D,D)) / cSample->dP;
// Directional error
float e2 = 1 - dotvv(N,cSample->N);
if (e2 < 0) e2 = 0;
e2 = sqrtf(e2*weightNormalDenominator);
// Compute the weight
float w = 1 - K*max(e1,e2);
if (w > context->urand()*smallSampleWeight) {
vector ntmp;
crossvv(ntmp,cSample->N,N);
// Sum the sample
totalWeight += w;
coverage += w*(cSample->coverage + dotvv(cSample->gP+0*3,D) + dotvv(cSample->gR+0*3,ntmp));
irradiance[0] += w*(cSample->irradiance[0] + dotvv(cSample->gP+1*3,D) + dotvv(cSample->gR+1*3,ntmp));
irradiance[1] += w*(cSample->irradiance[1] + dotvv(cSample->gP+2*3,D) + dotvv(cSample->gR+2*3,ntmp));
irradiance[2] += w*(cSample->irradiance[2] + dotvv(cSample->gP+3*3,D) + dotvv(cSample->gR+3*3,ntmp));
envdir[0] += w*(cSample->envdir[0] + dotvv(cSample->gP+4*3,D) + dotvv(cSample->gR+4*3,ntmp));
envdir[1] += w*(cSample->envdir[1] + dotvv(cSample->gP+5*3,D) + dotvv(cSample->gR+5*3,ntmp));
envdir[2] += w*(cSample->envdir[2] + dotvv(cSample->gP+6*3,D) + dotvv(cSample->gR+6*3,ntmp));
}
}
// Check the children
for (i=0;i<8;i++) {
CCacheNode *tNode;
if ((tNode = cNode->children[i]) != NULL) {
const float tSide = tNode->side;
if ( ((tNode->center[0] + tSide) > P[0]) &&
((tNode->center[1] + tSide) > P[1]) &&
((tNode->center[2] + tSide) > P[2]) &&
((tNode->center[0] - tSide) < P[0]) &&
((tNode->center[1] - tSide) < P[1]) &&
((tNode->center[2] - tSide) < P[2])) {
*stack++ = tNode;
}
}
}
}
// Do we have anything ?
if (totalWeight > C_EPSILON) {
double normalizer = 1 / totalWeight;
normalizevf(envdir);
C[0] = (float) (irradiance[0]*normalizer);
C[1] = (float) (irradiance[1]*normalizer);
C[2] = (float) (irradiance[2]*normalizer);
C[3] = (float) (coverage*normalizer);
mulmv(C+4,from,envdir); // envdir is stored in the target coordinate system
} else {
// Are we sampling the cache ?
if (flags & CACHE_SAMPLE) {
vector dPdu,dPdv;
// Convert the tangent space
mulmv(dPdu,to,cdPdu);
mulmv(dPdv,to,cdPdv);
// Create a new sample
sample(C,P,dPdu,dPdv,N,context);
mulmv(C+4,from,C+4); // envdir is stored in the target coordinate system
} else {
// No joy
C[0] = 0;
C[1] = 0;
C[2] = 0;
C[3] = 1;
C[4] = 0;
C[5] = 0;
C[6] = 0;
}
}
// Make sure we don't have NaNs
assert(dotvv(C,C) >= 0);
}
}
