private Illuminance ShootRay(Ray Ray, int loop)
{
if (loop == 0)
{
return(Illuminance.Black);
}
Shape shape = null;
var distance = double.PositiveInfinity;
foreach (var s in shapes)
{
var t = s.Intersection(Ray);
if (!t.IsPositive())
{
continue;
}
if (distance < t)
{
continue;
}
shape = s;
distance = t;
}
if (shape == null)
{
return(sky);
}
var result = new Illuminance();
var Intersection = Ray.Away(distance);
var Normal = shape.NormalVector(Intersection);
foreach (var l in lightes)
{
Illuminance light = l.Spotlight(this, shape, Intersection, Ray, Normal);
result = result.Add(light);
}
if (!shape.Material.FSRC.IsDark()) //鏡
{
var v = Ray.Direction.Reversed();
var d = Normal.Dot(v);
if (d > 0.0)
{
var r = Normal.Mul(2 * v.Dot(Normal)).Sub(v);
var ray = new Ray(Intersection.Add(r.Mul(MathHelper.Epsilon)), r);
result = result.Add(ShootRay(ray, loop - 1));
}
}
return(result);
}
public override Illuminance Spotlight(World World, Shape Shape, Vector3 Spot, Ray Ray, Vector3 Normal)
{
Vector3 Incident = Point.Sub(Spot);
double Dl = Incident.Norm() - MathHelper.Epsilon;
Incident.Normalize();
Ray shadow = new Ray(Spot.Add(Incident.Mul(MathHelper.Epsilon)), Incident);
foreach (var s in World.Shapes)
{
var t = s.Intersection(shadow);
if (t < Dl)
{
return(Illuminance.Black);
}
}
double d = Normal.Dot(Incident).ToRate();
Illuminance ld = Shape.Material.DRC.Mul(Illuminance.Mul(d));
if (d > 0.0 && (!Shape.Material.SRC.IsDark()) && Shape.Material.Shininess > 0.0)
{
Vector3 r = Normal.Mul(d * 2).Sub(Incident).Normalized();
Vector3 v = Ray.Direction.Reversed();
ld = ld.Add(Illuminance.Mul(Shape.Material.SRC.Mul(Math.Pow(r.Dot(v).ToRate(), Shape.Material.Shininess))));
}
return(ld);
}
