Radiance3 RayTracer::L_indirectImpulses(const shared_ptr<Surfel>& surfel, const Vector3& wo, ThreadData& threadData, int bouncesLeft) const {
Surfel::ImpulseArray impulseArray;
surfel->getImpulses(PathDirection::EYE_TO_SOURCE, wo, impulseArray);
Radiance3 L;
for (int i = 0; i < impulseArray.size(); ++i) {
const Surfel::Impulse& impulse = impulseArray[i];
L += L_in(bump(surfel, impulse.direction), impulse.direction, threadData, bouncesLeft) * impulse.magnitude;
}
return L;
}
Radiance3 App::rayTrace(const Ray& ray, World* world, int bounce) {
Radiance3 radiance = Radiance3::zero();
const float BUMP_DISTANCE = 0.0001f;
float dist = (float)inf();
const shared_ptr<Surfel>& surfel = world->intersect(ray, dist);
if (notNull(surfel)) {
// Shade this point (direct illumination)
for (int L = 0; L < world->lightArray.size(); ++L) {
const shared_ptr<Light>& light = world->lightArray[L];
// Shadow rays
if (world->lineOfSight(surfel->location + surfel->geometricNormal * BUMP_DISTANCE, light->position().xyz())) {
Vector3 w_i = light->position().xyz() - surfel->location;
const float distance2 = w_i.squaredLength();
w_i /= sqrt(distance2);
// Biradiance
const Biradiance3& B_i = light->color / (4.0f * pif() * distance2);
radiance +=
surfel->finiteScatteringDensity(w_i, -ray.direction()) *
B_i *
max(0.0f, w_i.dot(surfel->shadingNormal));
debugAssert(radiance.isFinite());
}
}
// Indirect illumination
// Ambient
radiance += surfel->reflectivity(m_rng) * world->ambient;
// Specular
if (bounce < m_maxBounces) {
// Perfect reflection and refraction
Surfel::ImpulseArray impulseArray;
surfel->getImpulses(PathDirection::EYE_TO_SOURCE, -ray.direction(), impulseArray);
for (int i = 0; i < impulseArray.size(); ++i) {
const Surfel::Impulse& impulse = impulseArray[i];
// Bump along normal *in the outgoing ray direction*.
const Vector3& offset = surfel->geometricNormal * sign(impulse.direction.dot(surfel->geometricNormal)) * BUMP_DISTANCE;
const Ray& secondaryRay = Ray::fromOriginAndDirection(surfel->location + offset, impulse.direction);
debugAssert(secondaryRay.direction().isFinite());
radiance += rayTrace(secondaryRay, world, bounce + 1) * impulse.magnitude;
debugAssert(radiance.isFinite());
}
}
// Add radiance proportional to the distance and fogginess. Divide by 2 so that there isn't too much fog
radiance += (radiance.one() * dist * m_fogginess)/2;
} else {
// Hit the sky
radiance = world->ambient;
// Add radiance proportional to fogginess. Multiply by 10 so the fog is noticeable
radiance += (radiance.one() * m_fogginess * 10);
}
return radiance;
}