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));
}
}
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 Vector normal(Vector pos)
{
return(Vector.norm(Vector.minus(pos, this.center)));
}