bool SceneNode::hit(const Ray& ray, double &tmin, Shading &s) {
// transform ray so in object co-ordinates
Ray local_ray(ray);
local_ray.direction = m_invtrans * ray.direction;
local_ray.origin = m_invtrans * ray.origin;
Shading shading(s.world);
double t;
tmin = 10E24;
Vector3D normal;
Material *mat;
for (ChildList::const_iterator it = m_children.begin(); it != m_children.end(); it++) {
SceneNode *object = (*it);
if (object->hit(local_ray, t, shading) && (t < tmin)) {
tmin = t;
normal = shading.hit_normal;
mat = shading.material;
}
}
if (shading.hit_object) {
s.hit_object = true;
s.t = tmin;
s.hit_normal = m_invtrans.transpose() * normal;
s.material = mat;
return true;
}
return false;
}
bool Mesh::hit(const Ray& ray, double &tmin, Shading &s) const
{
Ray local_ray(ray);
Shading shading(s.world);
double t;
tmin = 10E24;
Vector3D normal;
// check bounding box first
Shading shading2(s.world);
bool was_bound = m_boundbox->hit(ray,tmin,shading2);
if (!m_boundbox->hit(ray,tmin,shading2)) {
return false;
}
tmin = 10E24;
for (unsigned int i=0; i<m_triangles.size(); i++) {
Triangle triangle = m_triangles[i];
if (triangle.hit(local_ray, t, shading) && (t < tmin)) {
shading.hit_object = true;
tmin = t;
normal = shading.hit_normal;
}
}
if (shading.hit_object) {
s.hit_object = true;
s.t = tmin;
s.hit_normal = normal;
return true;
}
return false;
}
bool GeometryNode::hit(const Ray& ray, double &tmin, Shading &s) {
// transform ray so in object co-ordinates
Ray local_ray(ray);
local_ray.direction = m_invtrans * ray.direction;
local_ray.origin = m_invtrans * ray.origin;
// only hit if primitive hit
if (m_primitive->hit(local_ray, tmin, s)) {
s.hit_object = true;
s.material = m_material;
// translate normal back to WCS
s.hit_normal = m_invtrans.transpose() * s.hit_normal;
return true;
}
return false;
}
bool Rectangle::Intersect(const Ray &ray,
const RayInterval &interval,
SurfaceInteraction *const interaction) const {
// Compute local ray
Ray local_ray = TransformRay(world_to_local, ray);
// Check intersection with plane
if (std::abs(local_ray.Direction().y()) > 10e-6f) {
// Compute intersection with plane
float t = -local_ray.Origin().y() * local_ray.InvDirection().y();
// Check boundaries
if (interval.Inside(t)) {
// Compute intersection point
Vector3f hit_p = local_ray(t);
// Check hit point inside rectangle
if (hit_p.x() > -x_size / 2.f && hit_p.x() < x_size / 2.f &&
hit_p.z() > -z_size / 2.f && hit_p.z() < z_size / 2.f) {
// Fill interaction
interaction->hit_point = hit_p;
interaction->geom_frame = Frame(Vector3f(1.f, 0.f, 0.f),
Vector3f(0.f, 1.f, 0.f),
Vector3f(0.f, 0.f, 1.f));
interaction->sh_frame = Frame(Vector3f(1.f, 0.f, 0.f),
Vector3f(0.f, 1.f, 0.f),
Vector3f(0.f, 0.f, 1.f));
interaction->t = t;
interaction->wo = Normalize(-local_ray.Direction());
interaction->uv = Vector2f((hit_p.x() + x_size / 2.f) / x_size,
(hit_p.z() + z_size / 2.f) / z_size);
interaction->surface = this;
// Transform to global space
*interaction = TransformInteraction(local_to_world, world_to_local, *interaction);
return true;
}
}
}
return false;
}
bool Rectangle::IntersectP(const Ray &ray,
const RayInterval &interval) const {
// Compute local ray
Ray local_ray = TransformRay(world_to_local, ray);
// Check intersection with plane
if (std::abs(local_ray.Direction().y()) > EPS) {
// Compute intersection with plane
float t = -local_ray.Origin().y() * local_ray.InvDirection().y();
// Check boundaries
if (interval.Inside(t)) {
// Compute intersection point
Vector3f hit_p = local_ray(t);
// Check hit point inside rectangle
if (hit_p.x() > -x_size / 2.f && hit_p.x() < x_size / 2.f &&
hit_p.z() > -z_size / 2.f && hit_p.z() < z_size / 2.f) {
return true;
}
}
}
return false;
}
