Vec3 DirectShader::getRadiance(const Vec3& direction, const Intersection& intersection, unsigned int depth) const {
const size_t lightCount = scene.getLightCount();
Vec3 radiance(0.0f);
for ( size_t i = 0; i < lightCount; ++i) {
const Light& light = scene.getLight( i );
Vec3 l( light.getPosition() - intersection.getLocation() );
const float distance = l.normalizeRL();
const Vec3& normal = intersection.getNormal();
const float d1 = fmaxf(normal * l, 0.0f);
const float d2 = fmaxf( d1 * ((l * -1.0f) * light.getDirection()), 0.0f);
if ( d2 > 0.0f ) {
const RaySegment shadowRay( intersection.getLocation() + l * 0.00001, l, 0.0, distance );
// const RaySegmentIgnore shadowRay( intersection.getLocation(), l, intersection.getPrimitive(), 0.0, distance );
if ( ! scene.hasIntersection( shadowRay ) )
radiance += (light.getColor() ^ color) * d2;
}
}
return radiance;
}
Colour* rayTrace(const Colour& ambient, const Point3D& eye, Ray ray, SceneNode* root,
const std::list<Light*>& lights, int level, double fogDist){
if(level <= 0)
return NULL;
Intersection* i = root->intersect(ray);
bool fogOn = true;
if(fogDist <= 0)
fogOn = false;
if(i != NULL){
Colour color(0,0,0);
Colour fog(0.8,0.8,0.8);
Colour diffuse(0,0,0), specular(0,0,0);
Material* material = i->getMaterial();
Vector3D n = i->getNormal();
n.normalize();
Point3D p = i->getPoint();
Vector3D v = eye - p;
v.normalize();
for (std::list<Light*>::const_iterator I = lights.begin(); I != lights.end(); ++I) {
Light light = **I;
Vector3D l = light.position - p;
l.normalize();
Vector3D r = 2*l*n*n - l;
r.normalize();
// shadows
Ray lightRay = Ray(p, l);
Intersection* lightIsc = root->intersect(lightRay);
if(lightIsc == NULL){
// add light contribution
//std::cerr << "light" << std::endl;
if(n*l > 0)
diffuse = diffuse + material->getDiffuse() * (l*n) * light.colour;
if(r*v > 0)
specular = specular + material->getSpecular() * pow((r*v), material->getShininess()) * light.colour;
}
}
//secondaty rays
Vector3D r = 2*v*n*n - v;
r.normalize();
Ray refRay(p, r);
Colour* reflectedColor = rayTrace(ambient, eye, refRay, root, lights, level-1, fogDist);
if(reflectedColor != NULL){
if(n*r > 0)
diffuse = diffuse + material->getDiffuse() * (r*n) * material->getReflectivity() * (*reflectedColor);
if(r*v > 0)
specular = specular + material->getSpecular() * pow((r*v), material->getShininess()) * material->getReflectivity() * (*reflectedColor);
}
color = ambient*material->getColor() + diffuse + specular;
if(fogOn){
double dist = i->getT()/fogDist;
if(dist>1)
dist=1;
color = (1-dist)*color + dist*fog;
}
return new Colour(color);
}
return NULL;
}
