private Color shade(Intersection isect, Scene scene, double depth)
{
var d = isect.ray.dir;
var pos = Vector.plus(Vector.times(isect.dist, d), isect.ray.start);
var normal = isect.thing.normal(pos);
var reflectDir = Vector.minus(d, Vector.times(2, Vector.times(Vector.dot(normal, d), normal)));
var naturalColor = Color.plus(Color.background, this.getNaturalColor(isect.thing, pos, normal, reflectDir, scene));
var reflectedColor = (depth >= this.maxDepth) ? Color.grey : this.getReflectionColor(isect.thing, pos, normal, reflectDir, scene, depth);
return(Color.plus(naturalColor, reflectedColor));
}
public override Intersection intersect(Ray ray)
{
var denom = Vector.dot(norm, ray.dir);
if (denom > 0)
{
return(null);
}
else
{
var dist = (Vector.dot(norm, ray.start) + offset) / (-denom);
return(new Intersection(this, ray, dist));
}
}
Color addLight(Color col, Light light)
{
var ldis = Vector.minus(light.pos, pos);
var livec = Vector.norm(ldis);
var neatIsect = this.testRay(new Ray(pos, livec), scene);
var isInShadow = (neatIsect == null) ? false : (neatIsect <= Vector.mag(ldis));
if (isInShadow)
{
return(col);
}
else
{
var illum = Vector.dot(livec, norm);
var lcolor = (illum > 0) ? Color.scale(illum, light.color)
: Color.defaultColor;
var specular = Vector.dot(livec, Vector.norm(rd));
var scolor = (specular > 0) ? Color.scale(Math.Pow(specular, thing.surface.roughness), light.color)
: Color.defaultColor;
return(Color.plus(col, Color.plus(Color.times(thing.surface.diffuse(pos), lcolor),
Color.times(thing.surface.specular(pos), scolor))));
}
}
public override Intersection intersect(Ray ray)
{
var eo = Vector.minus(this.center, ray.start);
var v = Vector.dot(eo, ray.dir);
var dist = 0.0;
if (v >= 0)
{
var disc = this.radius2 - (Vector.dot(eo, eo) - v * v);
if (disc >= 0)
{
dist = v - Math.Sqrt(disc);
}
}
if (dist == 0)
{
return(null);
}
else
{
return(new Intersection(this, ray, dist));
}
}