public static Color phong(ISect record, Scene scene)
{
if (record == null) return null;
Color ambiant = new Color();
Color diffuse = new Color();
Color specular = new Color();
Vec3 position = Ray.GetPosition(record.Ray, record.Dist);
int i;
foreach (Light light in scene.lights)
{
ambiant += record.Thing.mat.Ambiant * light.mat.Ambiant;
var N = (position - record.Thing.Position).Normalize();
var L = (light.Position - position).Normalize();
var NDotL = N.Dot(L);
if (NDotL < 0) continue;
diffuse += record.Thing.mat.Diffuse * light.mat.Diffuse * NDotL;
var R = N * 2 * NDotL - L;
var V = (light.Position - position).Normalize();
var RdotV = R.Dot(V);
if (RdotV < 0) continue;
specular += record.Thing.mat.Specular * light.mat.Specular * (float)Math.Pow(RdotV, record.Thing.mat.shinyness);
}
return Clamp(ambiant + diffuse + specular);
}
public override ISect intersect(Ray currentRay)
{
ISect record = null;
float a = currentRay.Direction.Dot(currentRay.Direction);
float b = (currentRay.Origin - Position).Dot(currentRay.Direction) * 2.0f;
float c = (currentRay.Origin - Position).Dot(currentRay.Origin - Position) - (float)Math.Pow(radius,2.0);
float det = (float)Math.Pow(b, 2) - 4 * a * c;
if (det < 0)
return null;
float t1 = (-b + (float)Math.Sqrt(det)) / (2 * a);
float t2 = (-b - (float)Math.Sqrt(det)) / (2 * a);
if (t1 < 0 && t2 < 0)
return record;
record = new ISect();
record.Thing = this;
record.Ray = currentRay;
if (t1 < 0)
record.Dist = t2;
else if (t2 < 0)
record.Dist = t1;
else
record.Dist = Math.Min(t1, t2);
return record;
}