SColor RayTracer::shadeIntersection(Intersection in, uint d) {
if (d <= 0 || in.hasIntersected() == false) {
// terminate recursion
return SColor(0, 0, 0);
}
Vect shade(0, 0, 0);
Material *mat = in.getMaterial();
float kt = mat->getTransparency();
SColor ks = mat->getSpecColor();
SColor ka = mat->getAmbColor();
SColor Cd = mat->getDiffColor();
SColor ambLight = Whitted::AmbientLightning(kt, ka, Cd);
std::vector<Light *> lts = scene->getLights();
for (uint i = 0; i < lts.size(); i++) {
Light *l = lts.at(i);
SColor Sj = calculateShadowScalar(*l, in);
shade = shade + Whitted::Illumination(l, in, Sj);
}
SColor reflection;
if (ks.length() > 0) {
Ray r = in.calculateReflection();
Intersection rin = scene->calculateRayIntersection(r);
reflection = shadeIntersection(rin, d-1).linearMult(ks);
}
SColor refraction;
if (kt > 0) {
Ray r = in.calculateRefraction();
Intersection rin = scene->calculateRayIntersection(r);
refraction = shadeIntersection(rin, d-1).linearMult(kt);
}
shade = ambLight + shade + reflection + refraction;
return shade;
}
SColor RayTracer::calculateShadowScalar(Light <, Intersection &in) {
// cout << in.toString() << endl;
Vect p = lt.getPos();
Vect ori = in.calculateIntersectionPoint();// + in.calculateSurfaceNormal().linearMult(0.0001f);
Vect dir;
if (lt.getType() == DIRECTIONAL_LIGHT) {
dir = lt.getDir().invert();
} else {
dir = p - ori;
dir.normalize();
}
ori = ori + dir.linearMult(0.001f);
Ray shdw(ori, dir);
Intersection ins = scene->calculateRayIntersection(shdw);
Material *mat = ins.getMaterial();
if (!ins.hasIntersected()) {
// The point is in direct light
return SColor(1, 1, 1);
} else if (mat->getTransparency() <= 0.00000001) {
// The material is fully opaque
Vect pos = ins.calculateIntersectionPoint();
if (lt.getType() == DIRECTIONAL_LIGHT ||
ori.euclideanDistance(pos) < ori.euclideanDistance(lt.getPos())) {
// The ray intersects with an object before the light source
return SColor(0, 0, 0);
} else {
// The ray intersects with an object behind the lightsource
// or a direction light, thus fully in light
return SColor(1, 1, 1);
}
} else { // The shape is transparent
// Normalize the color for this material, and recursively trace for other
// transparent objects
SColor Cd = mat->getDiffColor();
float m = max(Cd.R(), max(Cd.G(), Cd.B()));
Cd.R(Cd.R()/m); Cd.G(Cd.G()/m); Cd.B(Cd.B()/m);
SColor Si = Cd.linearMult(mat->getTransparency());
return Si.linearMult(calculateShadowScalar(lt, ins));
}
}
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;
}
