HitRecord Plane::intersect(Ray ray) const
{
float d = -QVector3D::dotProduct(ray.getDirection(), planeVector.toVector3D());
float u = QVector4D::dotProduct(QVector4D(ray.getOrigin(), 1), planeVector);
float t = u / d;
if(ray.inRange(t))
{
return HitRecord(t, ray, material, planeVector.toVector3D());
}
else
{
return HitRecord();
}
}
HitRecord AreaLight::intersect(Ray ray) const
{
QVector3D ad = ray.getOrigin() - origin;
QVector3D abxac = QVector3D::crossProduct(uDirection, vDirection);
float w = -QVector3D::dotProduct(abxac, ray.getDirection());
if(w == 0) return HitRecord();
float t = QVector3D::dotProduct(abxac, ad) / w;
if(!ray.inRange(t)) return HitRecord();
QVector3D adxde = QVector3D::crossProduct(ad, ray.getDirection());
float u = QVector3D::dotProduct(adxde, vDirection) / w;
if(u < 0 || u > 1) return HitRecord();
float v = -QVector3D::dotProduct(adxde, uDirection) / w;
if(v < 0 || v > 1) return HitRecord();
return HitRecord(t, ray, this, normal);
}
HitRecord BezierCurve::intersect(const Ray &ray, const double dist, const double time) const {
HitRecord hit = HitRecord(dist);
//These are the endpoints of the line segment
double t = findIntersection(0.0, 1.0, ray);
if (t != 0.0){
hit.hit(t, this, matl, ray, n);
}
return hit;
}
std::pair<boost::optional<double>,HitRecord> Scene::hit(Ray r)
{
auto hit = std::make_pair(boost::optional<double>(), HitRecord());
// std::cout << r.depth << std::endl;
if(bbox.hit(r)){
for(auto& s:shapes)
{
auto cHit = s->hit(r);
auto m = min(hit.first,cHit.first);
if(m != hit.first)
{
hit = cHit;
}
}
}
return hit;
}
bool Disc::hit(const Ray& ray,
const float& tmin,
const float& tmax,
const float& time,
HitRecord& hitRecord) const
{
// o => origin of ray
// d => direction of ray
// p = o + t.d => equation of ray
//
// p => point on disc
// c => center of disc
// n => normal of disc
// r => radius of disc
// (p - c).n = 0 => equation of plane containing disc
//
// (o + t.d - c).n = 0
// o.n + t.d.n - c.n = 0
// t = (c - o).n / d.n
//
// p = o + t.d
// (p - c).(p - c) < r.r
float rdMultiplyDn = dot(ray.direction, normal);
if (rdMultiplyDn != 0.0f) // TODO Epsilon
{
float t = dot((center - ray.origin), normal) / rdMultiplyDn;
if (t >= tmin && t <= tmax)
{
Vec3 cp = ray.pointAtParameter(t) - center;
if (dot(cp, cp) < radiusSquare)
{
hitRecord = HitRecord(t, normal, color);
return true;
}
}
}
return false;
}
bool Sphere::hit(const Ray& ray,
const float& tmin,
const float& tmax,
const float& time,
HitRecord& hitRecord) const
{
// Fast Ray Sphere Intersection - Jeff Hultquist
// Graphics Gems I - Andrew S. Glassner - Page 388
Vec3 scSubtractRo = center - ray.origin;
float scSubtractRoSquare = dot(scSubtractRo, scSubtractRo);
float projection = dot(scSubtractRo, ray.direction);
float discriminant = radiusSquare -
(scSubtractRoSquare - (projection * projection));
if (discriminant > 0.0f)
{
// TODO Switch tmin tmax if required
//tmin = projection - sqrt(discriminant);
//tmax = projection + sqrt(discriminant);
float discriminantSqrt = sqrtf(discriminant);
float t = projection - discriminantSqrt;
if (t < tmin)
{
t = projection + discriminantSqrt;
}
if (t >= tmin && t <= tmax)
{
// valid hit
hitRecord = HitRecord(t,
(ray.direction * t - scSubtractRo).normal(),
color);
return true;
}
}
return false;
}
