/
Renderer.cpp
206 lines (195 loc) · 10.1 KB
/
Renderer.cpp
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#include "Renderer.hpp"
#include <QDebug>
#include "mathFunctions.hpp"
namespace photon_mapping {
Photon Renderer::emitAndScatter(Random &random) {
float currentRefractionIndex = 1.0;
Scene::Sample sample;
do {
sample = scene()->uniformOnSurface(random);
} while (luminance(sample.emission) * sample.emissionPower == 0.0f);
float hitDistance; Scene::Sample hit;
Ray ray;
ray.origin = sample.position;
do {
ray.direction = random.cosineDirection(sample.normal);
} while (!scene()->hit(ray, hitDistance, hit));
Photon photon;
photon.position = hit.position;
photon.direction = ray.direction;
photon.power = sample.emission * sample.emissionPower;
while (true) {
float action = random.uniformInRange01();
float specularLuminance = luminance(hit.specular);
if (action < specularLuminance) {
Ray reflectedRay;
reflectedRay.origin = hit.position;
reflectedRay.direction = reflect(ray.direction, hit.normal);
reflectedRay.origin += reflectedRay.direction * 0.001f;
ray = reflectedRay;
if (!scene()->hit(ray, hitDistance, hit)) {
photon.power = Color::BLACK;
break;
}
photon.position = hit.position;
photon.direction = ray.direction;
continue;
} else {
action -= specularLuminance;
}
float transmissionLuminance = luminance(hit.transmission);
if (action < transmissionLuminance) {
Ray transmittedRay;
transmittedRay.origin = hit.position;
if (dot(hit.normal, ray.direction) <= 0.0f) {
transmittedRay.direction = transmit(ray.direction, +hit.normal, 1.0f / hit.refractionIndex);
} else {
transmittedRay.direction = transmit(ray.direction, -hit.normal, hit.refractionIndex / 1.0f);
}
transmittedRay.origin += transmittedRay.direction * 0.001f;
ray = transmittedRay;
if (nan(sqrLength(ray.direction)) || !scene()->hit(ray, hitDistance, hit)) {
photon.power = Color::BLACK;
break;
}
photon.position = hit.position;
photon.direction = ray.direction;
continue;
} else {
action -= transmissionLuminance;
}
// absorbtion;
break;
}
return photon;
}
void Renderer::scatterPart(Random& random, std::vector<Photon>::iterator begin, std::vector<Photon>::iterator end) {
if (scene()->empty()) {
return;
}
for (std::vector<Photon>::iterator p = begin; p != end; ++p) {
*p = emitAndScatter(random);
}
}
Color Renderer::render(std::vector<PhotonMap::NearestPhoton>& nearestPhotons, Ray const& ray, int rayBounceCount) const {
Color radiance = Color::BLACK;
float hitDistance; Scene::Sample hit;
if (!scene()->hit(ray, hitDistance, hit)) {
return radiance;
}
{ // emitted radiance
radiance += hit.emission * hit.emissionPower;
}
{ // photon radiance
Color photonRadiance = Color::BLACK;
auto nearestPhotonsEnd = photonMap().nearest(hit.position, nearestPhotons.begin(), nearestPhotons.end());
Vector3f const& n = hit.normal;
Vector3f v = -ray.direction;
auto farthestPhotonIt = nearestPhotons.begin();
float farthestPhotonSqrDistance = farthestPhotonIt->sqrDistance;
for (auto& nearestPhoton : nearestPhotons) {
Photon const& photon = *nearestPhoton.photon;
Vector3f l = -photon.direction;
float ln = dot(l, n);
if (ln > 0.0f) {
photonRadiance += hit.diffuse * ln * photon.power;
Vector3f r = reflect(-l, n);
float rv = dot(r, v);
if (rv > 0.0f) {
photonRadiance += hit.specular * pow(rv, hit.specularPower) * photon.power;
}
}
}
photonRadiance /= pi() * farthestPhotonSqrDistance * photonCount();
radiance += photonRadiance;
}
{ // reflected radiance
if (rayBounceCount + 1 < maxRayBounceCount() && luminance(hit.specular) > 0.0f) {
Ray reflectedRay;
reflectedRay.origin = hit.position;
reflectedRay.direction = reflect(ray.direction, hit.normal);
reflectedRay.origin += reflectedRay.direction * 0.001f;
radiance += hit.specular * render(nearestPhotons, reflectedRay, rayBounceCount + 1);
}
}
{ // transmitted radiance
if (rayBounceCount + 1 < maxRayBounceCount() && luminance(hit.transmission) > 0.0f) {
Ray transmittedRay;
transmittedRay.origin = hit.position;
if (dot(hit.normal, ray.direction) <= 0.0f) {
transmittedRay.direction = transmit(ray.direction, +hit.normal, 1.0f / hit.refractionIndex);
} else {
transmittedRay.direction = transmit(ray.direction, -hit.normal, hit.refractionIndex / 1.0f);
}
transmittedRay.origin += transmittedRay.direction * 0.001f;
if (!nan(sqrLength(transmittedRay.direction))) {
radiance += hit.transmission * render(nearestPhotons, transmittedRay, rayBounceCount + 1);
}
}
}
return radiance;
}
void Renderer::renderPart(std::vector<PhotonMap::NearestPhoton>& nearestPhotons, Segment2i const& segment) {
Extent2i sufraceExtent = surface()->extent();
if (quality() < 0) {
float idealSampleSize = 1 << -quality();
Extent2i pixelCount = extent(segment);
idealSampleSize = min(idealSampleSize, (float)pixelCount.x);
idealSampleSize = min(idealSampleSize, (float)pixelCount.y);
Extent2i sampleCount;
sampleCount.x = pixelCount.x / idealSampleSize;
sampleCount.y = pixelCount.y / idealSampleSize;
Extent2i pixelCountPerSample;
pixelCountPerSample.x = pixelCount.x / sampleCount.x;
pixelCountPerSample.y = pixelCount.y / sampleCount.y;
Extent2i leftoverPixelCount;
leftoverPixelCount.x = pixelCount.x - pixelCountPerSample.x * sampleCount.x;
leftoverPixelCount.y = pixelCount.y - pixelCountPerSample.y * sampleCount.y;
Point2i pixelPositionBegin;
Point2i pixelPositionEnd;
Point2f samplePosition;
Point2i sample;
for (sample.y = 0; sample.y < sampleCount.y; ++sample.y) {
pixelPositionBegin.y = segment.min.y + pixelCountPerSample.y * (sample.y + 0) + min(sample.y + 0, leftoverPixelCount.y);
pixelPositionEnd.y = segment.min.y + pixelCountPerSample.y * (sample.y + 1) + min(sample.y + 1, leftoverPixelCount.y);
samplePosition.y = floor((pixelPositionBegin.y + pixelPositionEnd.y) / 2.0f);
for (sample.x = 0; sample.x < sampleCount.x; ++sample.x) {
pixelPositionBegin.x = segment.min.x + pixelCountPerSample.x * (sample.x + 0) + min(sample.x + 0, leftoverPixelCount.x);
pixelPositionEnd.x = segment.min.x + pixelCountPerSample.x * (sample.x + 1) + min(sample.x + 1, leftoverPixelCount.x);
samplePosition.x = floor((pixelPositionBegin.x + pixelPositionEnd.x) / 2.0f);
Ray ray = camera()->cast(samplePosition, sufraceExtent);
Color sampleColor = render(nearestPhotons, ray);
Color pixelColor = clamp(Color::BLACK, sampleColor, Color::WHITE);
Point2i pixelPosition;
for (pixelPosition.y = pixelPositionBegin.y; pixelPosition.y < pixelPositionEnd.y; ++pixelPosition.y) {
for (pixelPosition.x = pixelPositionBegin.x; pixelPosition.x < pixelPositionEnd.x; ++pixelPosition.x) {
checkInterrupts();
surface()->setPixel(pixelPosition, pixelColor);
}
}
}
}
} else {
int sampleCount = 1 << quality();
float sampleDistance = 1.0f / sampleCount;
float sampleWeight = 1.0f / sqr(sampleCount);
Point2i pixelPosition;
for (pixelPosition.y = segment.min.y; pixelPosition.y < segment.max.y; ++pixelPosition.y) {
for (pixelPosition.x = segment.min.x; pixelPosition.x < segment.max.x; ++pixelPosition.x) {
checkInterrupts();
Color sampleColor = Color::BLACK;
Point2f subPixelPosition;
for (subPixelPosition.y = sampleDistance / 2.0f; subPixelPosition.y < 1.0f; subPixelPosition.y += sampleDistance) {
for (subPixelPosition.x = sampleDistance / 2.0f; subPixelPosition.x < 1.0f; subPixelPosition.x += sampleDistance) {
Point2f samplePosition = Point2f(pixelPosition.x + subPixelPosition.x, pixelPosition.y + subPixelPosition.y);
Ray ray = camera()->cast(samplePosition, sufraceExtent);
sampleColor += render(nearestPhotons, ray) * sampleWeight;
}
}
Color pixelColor = clamp(Color::BLACK, sampleColor, Color::WHITE);
surface()->setPixel(pixelPosition, pixelColor);
}
}
}
}
}