bool Transform::intersect(const Ray & r, Hit & h, float tmin)
{
// Need to Transform Ray before do intersection
Matrix reverseMat = transformMat;
reverseMat.Inverse();
// cout << "Original Origin:\t" << r.getOrigin() << endl;
// cout << "Original Direction:\t" << r.getDirection() << endl;
Vec4f aug_origin(r.getOrigin(), 1);
Vec3f aug_dir = r.getDirection();
reverseMat.Transform(aug_origin);
reverseMat.TransformDirection(aug_dir);
// cout << "Now Origin:\t" << r.getOrigin() << endl;
// cout << "Now Direction:\t" << r.getDirection() << endl;
// aug_dir.Normalize();
Ray transRay(aug_dir, Vec3f(aug_origin[0], aug_origin[1], aug_origin[2]));
if ( !( object -> intersect(transRay, h, tmin) ) )
return false;
// After transforming Ray, we need to transform Normal
Matrix transposeRevMat = reverseMat;
transposeRevMat.Transpose();
Vec3f hn = h.getNormal();
transposeRevMat.Transform(hn);
hn.Normalize();
h.set(h.getT(), NULL, hn, r);
return true;
}
void shade(const Scene * scene, const int level, const C_FLT weight,
const Ray &ray, Intercept * intercepts, Color * color) {
Material * entryMat = intercepts[0].material,
* hitMat = intercepts[0].enter?
intercepts[0].primitive->material: ray.medium;
C_FLT specWeight = hitMat->specular.magnitude() * weight,
transWeight = hitMat->transmission.magnitude() * weight;
Vector3D specDir, transDir, normal;
std::vector<P_FLT> mapping;
Point3D interceptPoint = ray.rayPoint(intercepts[0].t);
intercepts[0].primitive->getIntersect(interceptPoint, &normal, &mapping);
if (dotProduct(ray.dir, normal) > 0.0f) {
normal.negate();
}
specularDirection(ray.dir, normal, &specDir);
bool transmission = transmissionDirection(entryMat, hitMat, ray.dir, normal,
&transDir);
*color += scene->ambience * hitMat->ambience;
for (std::vector<Light *>::const_iterator itr = scene->lights.begin();
itr != scene->lights.end(); itr++) {
Vector3D pointToLight = (*itr)->orig - interceptPoint;
P_FLT distanceToLight = pointToLight.normalize();
Ray rayToLight(interceptPoint, pointToLight, NULL);
P_FLT lightDotNormal = dotProduct(pointToLight, normal);
if (fGreaterZero(lightDotNormal) &&
fGreaterZero(shadow(scene, rayToLight, distanceToLight))) {
// Light source diffuse reflection
*color += (*itr)->color * hitMat->diffuse * lightDotNormal;
// Light source specular reflection
Vector3D h = pointToLight - ray.dir;
h.normalize();
P_FLT specDot = dotProduct(normal, h);
if (specDot > 0.0f) {
*color += (*itr)->color * hitMat->specular *
pow(specDot, hitMat->shine);
}
} else if (transmission && fLessZero(lightDotNormal) &&
fLessZero(shadow(scene, rayToLight, distanceToLight))) {
// Light source specular transmission
C_FLT refrRatio = hitMat->refraction / entryMat->refraction;
if (!fEqual(refrRatio, 1.0f)) {
Vector3D h_j = (-ray.dir - pointToLight * refrRatio) /
(refrRatio - 1);
h_j.normalize();
// TODO(kent): Define transmission highlight coefficient
*color += (*itr)->color * hitMat->transmission *
pow(dotProduct(-normal, h_j), hitMat->shine);
}
}
}
if (level < MAX_LEVEL) {
// Other body specular reflection
if (specWeight > MIN_WEIGHT) {
Ray specRay(interceptPoint, specDir, entryMat);
Color specColor;
trace(scene, level + 1, specWeight, specRay, &specColor);
*color += specColor * hitMat->specular;
}
// Other body specular transmission
if (transWeight > MIN_WEIGHT) {
if (transmission) {
Ray transRay(interceptPoint, transDir, hitMat);
Color transColor;
trace(scene, level + 1, transWeight, transRay, &transColor);
*color += transColor * hitMat->transmission;
} else {
// TODO(kent): Handle total internal reflection
}
}
}
if (intercepts[0].enter && intercepts[0].primitive->texture != NULL) {
*color *= intercepts[0].primitive->getTexColor(mapping);
}
}