float MicrofacetBRDF::evaluatePDFInternal(const BSDFQuery &query, const Vector3D &dir, float* revPDF) const {
if (dir.z * query.dir_sn.z <= 0) {
if (revPDF)
*revPDF = 0.0f;
return 0.0f;
}
bool entering = query.dir_sn.z >= 0.0f;
int32_t sign = entering ? 1 : -1;
Normal3D m = sign * halfVector(query.dir_sn, dir);
float dotHV = dot(query.dir_sn, m);
if (dotHV * sign <= 0) {
if (revPDF)
*revPDF = 0.0f;
return 0.0f;
}
float mPDF = m_D->evaluatePDF(sign * query.dir_sn, m);
float commonPDFTerm = 1.0f / (4 * dotHV * sign);
float ret = commonPDFTerm * mPDF;
SLRAssert(!std::isnan(commonPDFTerm) && !std::isinf(commonPDFTerm) && !std::isnan(mPDF) && !std::isinf(mPDF),
"commonPDFTerm: %g, mPDF: %g, wlIdx: %u, qDir: %s, dir: %s",
commonPDFTerm, mPDF, query.wlHint, query.dir_sn.toString().c_str(), dir.toString().c_str());
if (revPDF)
*revPDF = commonPDFTerm * m_D->evaluatePDF(sign * dir, m);
return ret;
}
SampledSpectrum MicrofacetBRDF::evaluateInternal(const BSDFQuery &query, const Vector3D &dir, SampledSpectrum* rev_fs) const {
if (dir.z * query.dir_sn.z <= 0) {
if (rev_fs)
*rev_fs = SampledSpectrum::Zero;
return SampledSpectrum::Zero;
}
bool entering = query.dir_sn.z >= 0.0f;
int32_t sign = entering ? 1 : -1;
Normal3D m = sign * halfVector(query.dir_sn, dir);
float dotHV = dot(query.dir_sn, m);
float D = m_D->evaluate(m);
SampledSpectrum F = m_F.evaluate(dotHV);
float G = m_D->evaluateSmithG1(query.dir_sn, m) * m_D->evaluateSmithG1(dir, m);
SampledSpectrum fs = F * D * G / (4 * query.dir_sn.z * dir.z);
SLRAssert(!fs.hasInf() && !fs.hasNaN(), "fs: %s, F: %s, G, %g, D: %g, wlIdx: %u, qDir: %s, dir: %s",
fs.toString().c_str(), F.toString().c_str(), G, D, query.wlHint, query.dir_sn.toString().c_str(), dir.toString().c_str());
if (rev_fs)
*rev_fs = fs;
return fs;
}
void
SceneBump::setup_model_height()
{
static const std::string vtx_shader_filename(GLMARK_DATA_PATH"/shaders/bump-height.vert");
static const std::string frg_shader_filename(GLMARK_DATA_PATH"/shaders/bump-height.frag");
static const LibMatrix::vec4 lightPosition(20.0f, 20.0f, 10.0f, 1.0f);
Model model;
if(!model.load("asteroid-low"))
return;
model.calculate_normals();
/* Calculate the half vector */
LibMatrix::vec3 halfVector(lightPosition.x(), lightPosition.y(), lightPosition.z());
halfVector.normalize();
halfVector += LibMatrix::vec3(0.0, 0.0, 1.0);
halfVector.normalize();
std::vector<std::pair<Model::AttribType, int> > attribs;
attribs.push_back(std::pair<Model::AttribType, int>(Model::AttribTypePosition, 3));
attribs.push_back(std::pair<Model::AttribType, int>(Model::AttribTypeNormal, 3));
attribs.push_back(std::pair<Model::AttribType, int>(Model::AttribTypeTexcoord, 2));
attribs.push_back(std::pair<Model::AttribType, int>(Model::AttribTypeTangent, 3));
model.convert_to_mesh(mesh_, attribs);
/* Load shaders */
ShaderSource vtx_source(vtx_shader_filename);
ShaderSource frg_source(frg_shader_filename);
/* Add constants to shaders */
frg_source.add_const("LightSourcePosition", lightPosition);
frg_source.add_const("LightSourceHalfVector", halfVector);
frg_source.add_const("TextureStepX", 1.0 / 1024.0);
frg_source.add_const("TextureStepY", 1.0 / 1024.0);
if (!Scene::load_shaders_from_strings(program_, vtx_source.str(),
frg_source.str()))
{
return;
}
std::vector<GLint> attrib_locations;
attrib_locations.push_back(program_["position"].location());
attrib_locations.push_back(program_["normal"].location());
attrib_locations.push_back(program_["texcoord"].location());
attrib_locations.push_back(program_["tangent"].location());
mesh_.set_attrib_locations(attrib_locations);
Texture::load(GLMARK_DATA_PATH"/textures/asteroid-height-map.png", &texture_,
GL_NEAREST, GL_NEAREST, 0);
}
SampledSpectrum MicrofacetBSDF::evaluateInternal(const BSDFQuery &query, const Vector3D &dir, SampledSpectrum* rev_fs) const {
bool entering = query.dir_sn.z >= 0.0f;
int32_t sign = entering ? 1 : -1;
float dotNVdotNL = dir.z * query.dir_sn.z;
if (dotNVdotNL > 0 && query.flags.matches(DirectionType::Reflection | DirectionType::AllFreq)) {
Normal3D m = sign * halfVector(query.dir_sn, dir);
float dotHV = dot(query.dir_sn, m);
float D = m_D->evaluate(m);
SampledSpectrum F = m_F.evaluate(dotHV);
float G = m_D->evaluateSmithG1(query.dir_sn, m) * m_D->evaluateSmithG1(dir, m);
SampledSpectrum fs = F * D * G / (4 * dotNVdotNL);
SLRAssert(!fs.hasInf() && !fs.hasNaN(), "fs: %s, F: %s, G, %g, D: %g, wlIdx: %u, qDir: %s, dir: %s",
fs.toString().c_str(), F.toString().c_str(), G, D, query.wlHint, query.dir_sn.toString().c_str(), dir.toString().c_str());
if (rev_fs)
*rev_fs = fs;
return fs;
}
else if (dotNVdotNL < 0 && query.flags.matches(DirectionType::Transmission | DirectionType::AllFreq)) {
const SampledSpectrum &eEnter = entering ? m_F.etaExt() : m_F.etaInt();
const SampledSpectrum &eExit = entering ? m_F.etaInt() : m_F.etaExt();
SampledSpectrum ret = SampledSpectrum::Zero;
for (int wlIdx = 0; wlIdx < SampledSpectrum::NumComponents; ++wlIdx) {
Normal3D m_wl = normalize(-(eEnter[wlIdx] * query.dir_sn + eExit[wlIdx] * dir));
float dotHV_wl = dot(query.dir_sn, m_wl);
float dotHL_wl = dot(dir, m_wl);
float F_wl = m_F.evaluate(dotHV_wl, wlIdx);
float G_wl = m_D->evaluateSmithG1(query.dir_sn, m_wl) * m_D->evaluateSmithG1(dir, m_wl);
float D_wl = m_D->evaluate(m_wl);
ret[wlIdx] = std::fabs(dotHV_wl * dotHL_wl) * (1 - F_wl) * G_wl * D_wl / std::pow(eEnter[wlIdx] * dotHV_wl + eExit[wlIdx] * dotHL_wl, 2);
SLRAssert(!std::isnan(ret[wlIdx]) && !std::isinf(ret[wlIdx]), "fs: %g, F: %g, G, %g, D: %g, wlIdx: %u, qDir: %s, dir: %s",
ret[wlIdx], F_wl, G_wl, D_wl, query.wlHint, query.dir_sn.toString().c_str(), dir.toString().c_str());
}
ret /= std::fabs(dotNVdotNL);
ret *= query.adjoint ? (eExit * eExit) : (eEnter * eEnter);// !adjoint: eExit^2 * (eEnter / eExit)^2
SLRAssert(!ret.hasInf() && !ret.hasNaN(), "fs: %s, wlIdx: %u, qDir: %s, dir: %s",
ret.toString().c_str(), query.wlHint, query.dir_sn.toString().c_str(), dir.toString().c_str());
if (rev_fs)
*rev_fs = ret;
return ret;
}
if (rev_fs)
*rev_fs = SampledSpectrum::Zero;
return SampledSpectrum::Zero;
}
float MicrofacetBSDF::evaluatePDFInternal(const BSDFQuery &query, const Vector3D &dir, float* revPDF) const {
bool entering = query.dir_sn.z >= 0.0f;
int32_t sign = entering ? 1 : -1;
float dotNVdotNL = dir.z * query.dir_sn.z;
if (dotNVdotNL == 0)
return 0.0f;
const SampledSpectrum &eEnter = entering ? m_F.etaExt() : m_F.etaInt();
const SampledSpectrum &eExit = entering ? m_F.etaInt() : m_F.etaExt();
Normal3D m;
if (dotNVdotNL > 0)
m = sign * halfVector(query.dir_sn, dir);
else
m = normalize(-(eEnter[query.wlHint] * query.dir_sn + eExit[query.wlHint] * dir));
float dotHV = dot(query.dir_sn, m);
if (dotHV * sign <= 0) {
if (revPDF)
*revPDF = 0.0f;
return 0.0f;
}
float mPDF = m_D->evaluatePDF(sign * query.dir_sn, m);
SampledSpectrum F = m_F.evaluate(dotHV);
float reflectProb = F.importance(query.wlHint);
if (query.flags.isReflection())
reflectProb = 1.0f;
if (query.flags.isTransmission())
reflectProb = 0.0f;
if (dotNVdotNL > 0) {
float commonPDFTerm = reflectProb / (4 * dotHV * sign);
SLRAssert(!std::isnan(commonPDFTerm) && !std::isinf(commonPDFTerm) && !std::isnan(mPDF) && !std::isinf(mPDF),
"commonPDFTerm: %g, mPDF: %g, F: %s, wlIdx: %u, qDir: %s, dir: %s",
commonPDFTerm, mPDF, F.toString().c_str(), query.wlHint, query.dir_sn.toString().c_str(), dir.toString().c_str());
if (revPDF)
*revPDF = commonPDFTerm * m_D->evaluatePDF(sign * dir, m);
return commonPDFTerm * mPDF;
}
else {
float dotHL = dot(dir, m);
float commonPDFTerm = (1 - reflectProb) / std::pow(eEnter[query.wlHint] * dotHV + eExit[query.wlHint] * dotHL, 2);
SLRAssert(!std::isnan(commonPDFTerm) && !std::isinf(commonPDFTerm) && !std::isnan(mPDF) && !std::isinf(mPDF),
"commonPDFTerm: %g, mPDF: %g, F: %s, wlIdx: %u, qDir: %s, dir: %s",
commonPDFTerm, mPDF, F.toString().c_str(), query.wlHint, query.dir_sn.toString().c_str(), dir.toString().c_str());
if (revPDF)
*revPDF = commonPDFTerm * m_D->evaluatePDF(-sign * dir, m) * eEnter[query.wlHint] * eEnter[query.wlHint] * std::fabs(dotHV);
return commonPDFTerm * mPDF * eExit[query.wlHint] * eExit[query.wlHint] * std::fabs(dotHL);
}
}
rgbColor newWard::f(const vec3& wo, const vec3& wi) const{
if(wo.y*wi.y < 0.f){
return rgbColor(0.f);
}
const vec3 wh = halfVector(wo, wi);
const float meanX = wh.x / alpha;
const float meanZ = wh.z / beta;
return Rs * exp( -(meanX*meanX + meanZ*meanZ) / (wh.y*wh.y)) /
(4.f * PI * alpha * beta * sqrt(wo.y*wi.y));
}
rgbColor substrate::f(const vec3& wo, const vec3& wi) const{
const rgbColor diffuse = ecTerm *
(1.f - pow(1.f - bsdf::cosTheta(wo) * 0.5f, 5)) *
(1.f - pow(1.f - bsdf::cosTheta(wi) * 0.5f, 5));
const vec3 wh = halfVector(wo, wi);
const float wiDotWh = abs(dot(wi, wh));
const rgbColor specular = (distrib->D(wh) * schlickFresnel(Rs, wiDotWh)) /
(8.f * PI * wiDotWh * std::max(bsdf::cosTheta(wo), bsdf::cosTheta(wi)));
return diffuse + specular;
}
void
SceneBump::setup_model_plain(const std::string &type)
{
static const std::string vtx_shader_filename(GLMARK_DATA_PATH"/shaders/bump-poly.vert");
static const std::string frg_shader_filename(GLMARK_DATA_PATH"/shaders/bump-poly.frag");
static const std::string low_poly_filename("asteroid-low");
static const std::string high_poly_filename("asteroid-high");
static const LibMatrix::vec4 lightPosition(20.0f, 20.0f, 10.0f, 1.0f);
Model model;
/* Calculate the half vector */
LibMatrix::vec3 halfVector(lightPosition.x(), lightPosition.y(), lightPosition.z());
halfVector.normalize();
halfVector += LibMatrix::vec3(0.0, 0.0, 1.0);
halfVector.normalize();
std::string poly_filename = type == "high-poly" ?
high_poly_filename : low_poly_filename;
if(!model.load(poly_filename))
return;
model.calculate_normals();
/* Tell the converter that we only care about position and normal attributes */
std::vector<std::pair<Model::AttribType, int> > attribs;
attribs.push_back(std::pair<Model::AttribType, int>(Model::AttribTypePosition, 3));
attribs.push_back(std::pair<Model::AttribType, int>(Model::AttribTypeNormal, 3));
model.convert_to_mesh(mesh_, attribs);
/* Load shaders */
ShaderSource vtx_source(vtx_shader_filename);
ShaderSource frg_source(frg_shader_filename);
/* Add constants to shaders */
frg_source.add_const("LightSourcePosition", lightPosition);
frg_source.add_const("LightSourceHalfVector", halfVector);
if (!Scene::load_shaders_from_strings(program_, vtx_source.str(),
frg_source.str()))
{
return;
}
std::vector<GLint> attrib_locations;
attrib_locations.push_back(program_["position"].location());
attrib_locations.push_back(program_["normal"].location());
mesh_.set_attrib_locations(attrib_locations);
}
float beckmann::pdf(const vec3& wo, const vec3& wi) const{
const vec3 wh = halfVector(wo, wi);
return D(wh) / (4.f * abs(dot(wo, wh)));
}
