float Warp::squareToHSWPDF(const Point2f &p, HSWrapper *testWrapper) {
float total = testWrapper->m_totalLum;
float height = testWrapper->m_lightprob.rows();
float width = testWrapper->m_lightprob.cols();
float fPixH = height * p(1);
float fPixW = width * p(0);
int y = int(std::min(height - 1.0f ,std::floor(fPixH)));
int x = int(std::min(width - 1.0f ,std::floor(fPixW)));
int yNext = y + 1;
int xNext = x + 1;
Color3f Q11 = testWrapper->m_lightprob(y, x);
Color3f Q21 = testWrapper->m_lightprob(y, std::min(int(width -1.0f), xNext));
Color3f Q12 = testWrapper->m_lightprob(std::min(int(height -1.0f), yNext), x);
Color3f Q22 = testWrapper->m_lightprob(std::min(int(height -1.0f), yNext), std::min(int(width -1.0f), xNext));
float fact1 = ((xNext - fPixW) / (xNext - x));
float fact2 = ((fPixW - x) / (xNext - x));
Color3f R1 = fact1 * Q11 + fact2 * Q21;
Color3f R2 = fact1 * Q12 + fact2 * Q22;
fact1 = ((yNext - fPixH) / (yNext - y));
fact2 = ((fPixH - y) / (yNext - y));
Color3f result = fact1 * R1 + fact2 * R2;
float lum = result.getLuminance();
if (lum < 0) {
cout << "Negative luminance detected : " << lum << endl;
}
float pdf = lum / total;
return pdf;
}
float Bitmap::getTotalLuminace(){
Color3f totalColor = sum();
float totalLum = totalColor.getLuminance();
return totalLum;
}
/// Invoke a series of t-tests on the provided input
void activate() {
int total = 0, passed = 0;
pcg32 random;
if (!m_bsdfs.empty()) {
if (m_references.size() * m_bsdfs.size() != m_angles.size())
throw NoriException("Specified a different number of angles and reference values!");
if (!m_scenes.empty())
throw NoriException("Cannot test BSDFs and scenes at the same time!");
/* Test each registered BSDF */
int ctr = 0;
for (auto bsdf : m_bsdfs) {
for (size_t i=0; i<m_references.size(); ++i) {
float angle = m_angles[i], reference = m_references[ctr++];
cout << "------------------------------------------------------" << endl;
cout << "Testing (angle=" << angle << "): " << bsdf->toString() << endl;
++total;
BSDFQueryRecord bRec(sphericalDirection(degToRad(angle), 0));
cout << "Drawing " << m_sampleCount << " samples .. " << endl;
double mean=0, variance = 0;
for (int k=0; k<m_sampleCount; ++k) {
Point2f sample(random.nextFloat(), random.nextFloat());
double result = (double) bsdf->sample(bRec, sample).getLuminance();
/* Numerically robust online variance estimation using an
algorithm proposed by Donald Knuth (TAOCP vol.2, 3rd ed., p.232) */
double delta = result - mean;
mean += delta / (double) (k+1);
variance += delta * (result - mean);
}
variance /= m_sampleCount - 1;
std::pair<bool, std::string>
result = hypothesis::students_t_test(mean, variance, reference,
m_sampleCount, m_significanceLevel, (int) m_references.size());
if (result.first)
++passed;
cout << result.second << endl;
}
}
} else {
if (m_references.size() != m_scenes.size())
throw NoriException("Specified a different number of scenes and reference values!");
Sampler *sampler = static_cast<Sampler *>(
NoriObjectFactory::createInstance("independent", PropertyList()));
int ctr = 0;
for (auto scene : m_scenes) {
const Integrator *integrator = scene->getIntegrator();
const Camera *camera = scene->getCamera();
float reference = m_references[ctr++];
cout << "------------------------------------------------------" << endl;
cout << "Testing scene: " << scene->toString() << endl;
++total;
cout << "Generating " << m_sampleCount << " paths.. " << endl;
double mean = 0, variance = 0;
for (int k=0; k<m_sampleCount; ++k) {
/* Sample a ray from the camera */
Ray3f ray;
Point2f pixelSample = (sampler->next2D().array()
* camera->getOutputSize().cast<float>().array()).matrix();
Color3f value = camera->sampleRay(ray, pixelSample, sampler->next2D());
/* Compute the incident radiance */
value *= integrator->Li(scene, sampler, ray);
/* Numerically robust online variance estimation using an
algorithm proposed by Donald Knuth (TAOCP vol.2, 3rd ed., p.232) */
double result = (double) value.getLuminance();
double delta = result - mean;
mean += delta / (double) (k+1);
variance += delta * (result - mean);
}
variance /= m_sampleCount - 1;
std::pair<bool, std::string>
result = hypothesis::students_t_test(mean, variance, reference,
m_sampleCount, m_significanceLevel, (int) m_references.size());
if (result.first)
++passed;
cout << result.second << endl;
}
}
cout << "Passed " << passed << "/" << total << " tests." << endl;
}
