Colour SceneNode::get_colour(Point3D origin, Vector3D dir, const Colour& ambient,
const Colour& bg, const std::list<Light*>& lights,
int num_glossy_rays, int limit) {
HitInfo info = intersects(origin, dir);
if (!info.empty() && limit > 0) {
Hit closest = info.get_closest();
Material* close_mat = closest.material;
Colour c(0.0, 0.0, 0.0);
for (std::list<Light*>::const_iterator it = lights.begin(); it != lights.end(); ++it) {
Vector3D shadow_ray = (*it)->position - closest.intersection;
HitInfo shadow_info = intersects(closest.intersection, shadow_ray);
closest = close_mat->apply_material(-dir, *it, closest);
if (!shadow_info.empty()) {
std::vector<Hit> all_hits = shadow_info.get_all_hits();
int num_translucent = 0;
Colour shadow(0.0, 0.0, 0.0);
for (unsigned int i = 0; i < all_hits.size(); i++) {
Hit h = all_hits.at(i);
if (!h.in_shadow) {
if (num_translucent == 0) {
shadow = shadow + closest.diffuse;
num_translucent = 1;
}
break;
} else {
if ((h.material)->get_transparency() > 0.0) {
shadow = shadow + (h.material)->get_transparency() * closest.diffuse;
num_translucent++;
} else {
num_translucent = 0;
break;
}
}
}
if (num_translucent > 0) {
c = c + (1.0 / num_translucent) * shadow;
c = c + closest.specular;
}
} else {
c = c + closest.diffuse;
c = c + closest.specular;
}
}
if ((closest.material)->should_reflect()) {
Vector3D V = dir, N = closest.normal;
V.normalize(); N.normalize();
Vector3D reflected = V - (2 * V.dot(N) * N);
Colour r = get_colour(closest.intersection, reflected, ambient, bg, lights,
num_glossy_rays, limit - 1);
if (num_glossy_rays > 0) {
Vector3D w = reflected;
w.normalize();
Vector3D u = w.cross(Vector3D(1.0, 0.0, 0.0));
u.normalize();
Vector3D v = w.cross(Vector3D(0.0, 1.0, 0.0));
v.normalize();
for (int i = 0; i < num_glossy_rays; i++) {
double dx = 0.0;
double dy = 0.0;
while (dx == 0.0 && dy == 0.0) {
dx = ((double)(rand() % 100) / 100.0) * 0.125;
dy = ((double)(rand() % 100) / 100.0) * 0.125;
}
Vector3D refi = reflected + dx * u + dy * v;
if (refi.dot(closest.normal) < 0) {
refi = -refi;
}
Colour ri = get_colour(closest.intersection, refi, ambient, bg, lights,
num_glossy_rays, limit - 1);
r = r + ri;
}
r = (double) (1.0 / (num_glossy_rays + 1)) * r;
}
c = 0.7 * c + 0.3 * close_mat->get_reflect(r);
}
Vector3D refracted;
if (close_mat->should_refract() && close_mat->get_transmit_ray(refracted, dir, closest)) {
Colour refr = get_colour(closest.intersection, refracted, ambient, bg, lights,
num_glossy_rays, limit + 1);
c = c + close_mat->get_transparency() * refr;
}
c = c + (1.0 - close_mat->get_transparency()) * close_mat->get_ambient(ambient);
return c;
} else {
return bg;
}
}
HitInfo CSGNode::intersects(Point3D origin, Vector3D dir) const {
HitInfo info;
origin = get_inverse() * origin;
dir = get_inverse() * dir;
bool first = true;
for (ChildList::const_iterator it = m_children.begin(); it != m_children.end(); ++it) {
HitInfo h = (*it)->intersects(origin, dir);
for (unsigned int i = 0; i < h.hits.size(); i++) {
h.hits.at(i).intersection = get_transform() * h.hits.at(i).intersection;
h.hits.at(i).normal = get_inverse().transpose() * h.hits.at(i).normal;
}
for (unsigned int i = 0; i < h.lines.size(); i++) {
h.lines.at(i).first.intersection = get_transform() *
h.lines.at(i).first.intersection;
h.lines.at(i).second.intersection = get_transform() *
h.lines.at(i).second.intersection;
h.lines.at(i).first.normal = get_inverse().transpose() *
h.lines.at(i).first.normal;
h.lines.at(i).second.normal = get_inverse().transpose() *
h.lines.at(i).second.normal;
}
switch(m_type) {
case UNION: {
info = HitInfo::merge_info(info, h);
break;
}
case INTERSECTION: {
if (first) {
info = h;
} else if (h.empty()) {
info.clear();
return info;
} else {
std::vector<HitInfo::LineSegment> lines;
for (unsigned int i = 0; i < info.lines.size(); i++) {
HitInfo::LineSegment line = info.lines.at(i);
for (unsigned int j = 0; j < h.lines.size(); j++) {
HitInfo::LineSegment sub = h.lines.at(j);
if (line.first.t >= sub.first.t && line.second.t <= sub.second.t) {
// subtracting line contains the first line
lines = HitInfo::insert_line_in_order(lines, line);
} else if (line.first.t < sub.first.t && line.second.t > sub.second.t) {
// first line contains subtracting line
lines = HitInfo::insert_line_in_order(lines, sub);
} else if (line.first.t > sub.first.t && line.first.t < sub.second.t &&
line.second.t > sub.second.t) {
// tail end of line overlaps with subtracting line.
double len = (sub.second.intersection-line.first.intersection).length();
if (len > EPSILON) {
lines = HitInfo::insert_line_in_order(lines,
std::make_pair(line.first, sub.second));
}
} else if (line.first.t < sub.first.t && line.second.t > sub.first.t &&
line.second.t < sub.second.t) {
// head end of line overlaps with subtracting line
double len = (line.second.intersection-sub.first.intersection).length();
if (len > EPSILON) {
lines = HitInfo::insert_line_in_order(lines,
std::make_pair(sub.first, line.second));
}
} else {
// no overlap, do nothing
continue;
}
}
}
info.lines = lines;
std::vector<Hit> hits;
for (unsigned i = 0; i < info.hits.size(); i++) {
Hit hit = info.hits.at(i);
for (unsigned j = 0; j < h.lines.size(); j++) {
HitInfo::LineSegment sub = h.lines.at(j);
if (hit.t > sub.first.t && hit.t < sub.second.t) {
hits.push_back(hit);
break;
}
}
}
info.hits = hits;
}
break;
}
case DIFFERENCE: {
if (first && h.empty()) {
return info;
} else if (first && !h.empty()) {
info = HitInfo::merge_info(info, h);
} else if (!h.empty()) {
std::vector<HitInfo::LineSegment> lines;
for (unsigned int i = 0; i < info.lines.size(); i++) {
HitInfo::LineSegment line = info.lines.at(i);
for (unsigned int j = 0; j < h.lines.size(); j++) {
HitInfo::LineSegment sub = h.lines.at(j);
if (line.first.t >= sub.first.t && line.second.t <= sub.second.t) {
// subtracting line contains the first line
continue;
} else if (line.first.t < sub.first.t && line.second.t > sub.second.t) {
// first line contains subtracting line; divide into two lines.
sub.first.normal = -sub.first.normal;
sub.second.normal = -sub.second.normal;
double len1 = (sub.first.intersection -
line.first.intersection).length();
double len2 = (line.second.intersection-
sub.second.intersection).length();
if (len1 > EPSILON) {
lines = HitInfo::insert_line_in_order(lines,
std::make_pair(line.first, sub.first));
}
if (len2 > EPSILON) {
lines = HitInfo::insert_line_in_order(lines,
std::make_pair(sub.second, line.second));
}
} else if (line.first.t > sub.first.t && line.first.t < sub.second.t &&
line.second.t > sub.second.t) {
// head end of line overlaps with subtracting line.
sub.second.normal = -sub.second.normal;
double len = (line.second.intersection-sub.second.intersection).length();
if (len > EPSILON) {
lines = HitInfo::insert_line_in_order(lines,
std::make_pair(sub.second, line.second));
}
} else if (line.first.t < sub.first.t && line.second.t > sub.first.t &&
line.second.t < sub.second.t) {
// tail end of line overlaps with subtracting line
sub.first.normal = -sub.first.normal;
double len = (line.first.intersection-
sub.first.intersection).length();
if (len > EPSILON) {
lines = HitInfo::insert_line_in_order(lines,
std::make_pair(line.first, sub.first));
}
} else {
// no overlap, line remains unchanged.
lines = HitInfo::insert_line_in_order(lines, line);
}
}
}
info.lines = lines;
std::vector<Hit> hits;
for (unsigned i = 0; i < info.hits.size(); i++) {
Hit hit = info.hits.at(i);
bool insert = true;
for (unsigned j = 0; j < h.lines.size(); j++) {
HitInfo::LineSegment sub = h.lines.at(j);
if (hit.t > sub.first.t && hit.t < sub.second.t) {
insert = false;
}
}
if (insert) {
hits.push_back(hit);
}
}
info.hits = hits;
}
break;
}
}
first = false;
}
return info;
}