bool Cylinder::intersectCap(const Ray &localRay, double &t)
{
if (localRay.direction().y() < 0.0)
t = (0.5 * m_length - localRay.origin().y()) / localRay.direction().y();
else if (localRay.direction().y() > 0.0)
t = (-0.5 * m_length - localRay.origin().y()) / localRay.direction().y();
else
return false;
QVector4D p = localRay.along(t);
if (p.x() * p.x() + p.z() * p.z() < m_rSq)
return true;
return false;
}
QVector3D WhittedRenderer::trace(const Ray& primaryRay, int depth, const QList<Shape*>& shapes, const QList<Light*>& lights)
{
double minDist = std::numeric_limits<double>::max();
Shape* closestShape = nullptr;
QVector3D shaded;
if (m_grid->intersect(primaryRay, closestShape, minDist)) {
auto material = closestShape->material();
shaded = material->ambientReflectivity() * m_ambientLightColor * material->colorVector();
QColor color = material ? material->color() : QColor(40, 40, 40);
QVector3D diffuseColor(color.redF(), color.greenF(), color.blueF());
QVector4D hitPoint = primaryRay.along(minDist);
QVector4D normalVector = closestShape->surfaceNormal(hitPoint, primaryRay);
QVector4D viewVector = -primaryRay.direction();
foreach(Light* light, lights) {
QVector3D emittance;
QVector4D lightVector;
light->sample(lightVector, emittance);
lightVector = lightVector - hitPoint;
float lightVectorLengthSquared = lightVector.lengthSquared();
float lightVectorLength = sqrt(lightVectorLengthSquared);
lightVector.normalize();
Ray shadowRay(hitPoint, lightVector);
double t;
Shape* blockingShape;
bool shadowRayHit = m_grid->intersect(shadowRay, blockingShape, t);
if (!shadowRayHit || (shadowRayHit && (lightVectorLengthSquared < t * t))) {
// Diffuse
float dot = fmax(0.0f, QVector4D::dotProduct(lightVector, normalVector)) * material->diffuseReflectivity();
emittance *= 1 / (1 + 0.2 * lightVectorLength + 0.08 * lightVectorLengthSquared);
shaded += dot * QVector3D(emittance.x() * diffuseColor.x(),
emittance.y() * diffuseColor.y(),
emittance.z() * diffuseColor.z());
// Specular
if (material->specularReflectivity() > 0.0) {
QVector4D reflectedLightVector = MathUtils::reflect(-lightVector, normalVector); // lightVector and normalVector are already normalized
float dot = QVector4D::dotProduct(reflectedLightVector, viewVector);
if (dot > 0.0)
shaded += material->specularReflectivity() * pow(dot, material->shininess()) * emittance;
}
}
}
