public Vec GetRayColor(Ray r, ref HitableList world, int depth)
{
HitRecord rec = new HitRecord();
if (depth <= 0)
{
return(new Vec(0, 0, 0)); // no more color contribution
}
if (world.Hit(r, 0.001, Double.MaxValue, ref rec))
{
Ray scattered = new Ray();
Vec attenuation = new Vec();
if (rec.Material.Scatter(r, ref rec, ref attenuation, ref scattered))
{
return(attenuation * GetRayColor(scattered, ref world, depth - 1));
}
return(new Vec(0, 0, 0));
}
Vec dir = r.Direction.Normalize();
double t = 0.5 * (dir.Y + 1.0);
return((1.0 - t) * new Vec(1.0, 1.0, 1.0) + t * new Vec(0.5, 0.7, 1.0));
}
public Bitmap Render()
{
int nbSamples = 100;
int maxDepth = 10;
HitableList world = new HitableList();
var groundMaterial = new Lambertian(new Vec(0.8, 0.8, 0.8));
var pinkMaterial = new Lambertian(new Vec(1, 0, 0.57));
var redMaterial = new Metal(new Vec(0.8, 0.3, 0.3));
var mirrorMaterial = new Metal(new Vec(0.8, 0.8, 0.8));
var blueMaterial = new Metal(new Vec(0.3, 0.7, 1));
var greenMaterial = new Metal(new Vec(0.3, 0.7, 0.3));
world.Add(new Sphere(new Vec(0.0, -100.5, -1.0), 100.0, groundMaterial)); // ground
world.Add(new Sphere(new Vec(0.0, -0.0, -1.5), 0.5, mirrorMaterial)); // center
world.Add(new Sphere(new Vec(-1.0, -0.0, -1.0), 0.5, redMaterial)); // left
world.Add(new Sphere(new Vec(1.0, -0.2, -1.0), 0.3, blueMaterial)); // rsight
world.Add(new Sphere(new Vec(0.5, -0.0, 10.5), 10, greenMaterial)); // back
world.Add(new Sphere(new Vec(0.3, -0.4, -1.0), 0.1, pinkMaterial)); // back
world.Add(new Sphere(new Vec(0.4, -0.4, -0.2), 0.1, pinkMaterial)); // back
Camera cam = new Camera(90.0, _aspectRatio);
for (int j = _imageHeight - 1; j >= 0; j--)
{
Console.WriteLine($"Computing line {_imageHeight - j} of {_imageHeight}");
for (int i = 0; i < _imageWidth; i++)
{
Vec col = new Vec(0, 0, 0);
for (int sample = 0; sample < nbSamples; sample++)
{
double u = (double)(i + RNG.val.NextDouble()) / (double)_imageWidth;
double v = (double)(j + RNG.val.NextDouble()) / (double)_imageHeight;
Ray r = cam.GetRay(u, v);
col += GetRayColor(r, ref world, maxDepth);
}
_map.SetPixel(i, _imageHeight - j - 1, GetRGBColor(col, nbSamples));
}
}
return(_map);
}