protected override Intersections LocalIntersect(Ray ray)
{
var i = new Intersections();
if (Math.Abs(ray.Direction.y) < MathHelper.Epsilon)
{
return(i);
}
var t = -ray.Origin.y / ray.Direction.y;
i.Add(new Intersection(t, this));
return(i);
}
protected override Intersections LocalIntersect(Ray ray)
{
var intersections = new Intersections();
CheckAxis(ray.Origin.x, ray.Direction.x, out double xtmin, out double xtmax);
CheckAxis(ray.Origin.y, ray.Direction.y, out double ytmin, out double ytmax);
CheckAxis(ray.Origin.z, ray.Direction.z, out double ztmin, out double ztmax);
var tmin = Math.Max(xtmin, Math.Max(ytmin, ztmin));
var tmax = Math.Min(xtmax, Math.Min(ytmax, ztmax));
if (tmin <= tmax)
{
intersections.Add(new Intersection(tmin, this));
intersections.Add(new Intersection(tmax, this));
}
return(intersections);
}
private void IntersectCaps(Ray ray, Intersections xs)
{
if (!Closed || ray.Direction.y.IsEqual(0))
{
return;
}
var t = (Minimum - ray.Origin.y) / ray.Direction.y;
if (CheckCap(ray, t))
{
xs.Add(new Intersection(t, this));
}
t = (Maximum - ray.Origin.y) / ray.Direction.y;
if (CheckCap(ray, t))
{
xs.Add(new Intersection(t, this));
}
}
protected override Intersections LocalIntersect(Ray ray)
{
var result = new Intersections();
var sphereToRay = new Vector(ray.Origin - Point.Zero);
var a = ray.Direction.Dot(ray.Direction);
var b = 2.0 * ray.Direction.Dot(sphereToRay);
var c = sphereToRay.Dot(sphereToRay) - 1;
var discriminant = b * b - 4 * a * c;
if (discriminant < 0.0)
{
return(result);
}
else
{
result.Add(new Intersection((-b - Math.Sqrt(discriminant)) / (2 * a), this));
result.Add(new Intersection((-b + Math.Sqrt(discriminant)) / (2 * a), this));
}
return(result);
}
public Computations PrepareComputations(Ray r, Intersections xs)
{
List <RTObject> containers = new List <RTObject>();
var p = r.Position(t);
var eyev = -r.Direction;
var normv = Object.NormalAt(p, this);
var inside = false;
if (normv.Dot(eyev) < 0)
{
inside = true;
normv = -normv;
}
var reflv = r.Direction.Reflect(normv);
var n1 = 1.0;
var n2 = 1.0;
foreach (var i in xs)
{
if (this == i)
{
if (containers.Count == 0)
{
n1 = 1.0;
}
else
{
n1 = containers[containers.Count - 1].Material.RefractiveIndex;
}
}
if (containers.Contains(i.Object))
{
containers.Remove(i.Object);
}
else
{
containers.Add(i.Object);
}
if (this == i)
{
if (containers.Count == 0)
{
n2 = 1.0;
}
else
{
n2 = containers[containers.Count - 1].Material.RefractiveIndex;
}
break;
}
}
return(new Computations(t,
Object,
p,
eyev,
normv,
reflv,
n1,
n2,
inside));
}
