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