private IEnumerable<ISect> Intersections(Ray ray, Scene scene)
{
return scene.Things
.Select(obj => obj.Intersect(ray))
.Where(inter => inter != null)
.OrderBy(inter => inter.Dist);
}
private Color TraceRay(Ray ray, Scene scene, int depth)
{
var isects = Intersections(ray, scene);
ISect isect = isects.FirstOrDefault();
if (isect == null)
return Color.Background;
return Shade(isect, scene, depth);
}
private double TestRay(Ray ray, Scene scene)
{
var isects = Intersections(ray, scene);
ISect isect = isects.FirstOrDefault();
if (isect == null)
return 0;
return isect.Dist;
}
public IEnumerable<ISect> Intersect(Ray r) {
return from thing in Things
select thing.Intersect(r);
}
public override ISect Intersect(Ray ray) {
double denom = Vector.Dot(Norm, ray.Dir);
if (denom > 0) return null;
return new ISect() {
Thing = this,
Ray = ray,
Dist = (Vector.Dot(Norm, ray.Start) + Offset) / (-denom)};
}
public override ISect Intersect(Ray ray) {
Vector eo = Vector.Minus(Center, ray.Start);
double v = Vector.Dot(eo, ray.Dir);
double dist;
if (v < 0) {
dist = 0;
}
else {
double disc = Math.Pow(Radius,2) - (Vector.Dot(eo, eo) - Math.Pow(v,2));
dist = disc < 0 ? 0 : v - Math.Sqrt(disc);
}
if (dist == 0) return null;
return new ISect() {
Thing = this,
Ray = ray,
Dist = dist};
}
public abstract ISect Intersect(Ray ray);
