private Vector3 albedo;//漫反射系数
public override bool Scatter(Ray rIn, HitRecord rec, ref Vector3 attenuation, ref Ray scattered)
{
Vector3 target = rec.P + rec.Normal + RTUtils.RandomInUnitSphere();
scattered = new Ray(new Point3D(rec.P.X, rec.P.Y, rec.P.Z), target - rec.P);
attenuation = albedo;
return(true);
}
private void button1_Click(object sender, EventArgs e)
{
int nx = 1080;
int ny = 1080;
int ns = 10;
bmp = new Bitmap(nx, ny);
Random rd = new Random();
List <Hitable> list = new List <Hitable>();
list.Add(new Sphere(new Point3D(0, 0, -1), 0.5, new Lambertian(new Vector3(0.8, 0.3, 0.3))));
list.Add(new Sphere(new Point3D(0, -100.5, -1), 100, new Lambertian(new Vector3(0.8, 0.8, 0.0))));
list.Add(new Sphere(new Point3D(1, 0, -1), 0.5, new Metal(new Vector3(0.8, 0.6, 0.2), 0.3)));
list.Add(new Sphere(new Point3D(-1, 0, -1), 0.5, new Dielectrics(1.5)));
HitableList world = new HitableList(list, 4);
Camera cam = new Camera(new Point3D(-2, 2, 1), new Point3D(0, 0, -1), new Vector3(0, 1, 0), 90, (double)(nx) / (double)(ny));
for (int i = 0; i < nx; i++)
{
for (int j = 0; j < ny; j++)
{
Color3D col = new Color3D();
for (int s = 0; s < ns; s++)
{
double u = (double)(i + rd.NextDouble()) / (double)nx;
double v = (double)(j + rd.NextDouble()) / (double)ny;
Ray r = cam.GetRay(u, v);
Color3D colTemp = RTUtils.Color(r, world, 0);
col.R += colTemp.R;
col.G += colTemp.G;
col.B += colTemp.B;
}
col.R /= ns;
col.G /= ns;
col.B /= ns;
col = new Color3D(Math.Sqrt(col.R), Math.Sqrt(col.G), Math.Sqrt(col.B));
int ir = (int)(255.99 * col.R);
int ig = (int)(255.99 * col.G);
int ib = (int)(255.99 * col.B);
bmp.SetPixel(i, ny - j - 1, Color.FromArgb(ir, ig, ib));
}
}
pictureBox1.BackgroundImage = bmp;
}
public override bool Scatter(Ray rIn, HitRecord rec, ref Vector3 attenuation, ref Ray scattered)
{
Vector3 outwardNormal = new Vector3();
Vector3 reflected = RTUtils.Reflect(rIn.Direction, rec.Normal);
double niOverNt;
attenuation = new Vector3(1, 1, 1); //衰减率
Vector3 refracted = new Vector3();
double reflect_prob;
double cosine;
if (Vector3.DotProduct(rIn.Direction, rec.Normal) > 0)
{
outwardNormal = rec.Normal * -1;
niOverNt = refIdx;
cosine = refIdx * Vector3.DotProduct(rIn.Direction, rec.Normal) / rIn.Direction.Length();
}
else
{
outwardNormal = rec.Normal;
niOverNt = 1.0 / refIdx;
cosine = -Vector3.DotProduct(rIn.Direction, rec.Normal) / rIn.Direction.Length();
}
if (RTUtils.Refract(rIn.Direction, outwardNormal, niOverNt, ref refracted))
{
reflect_prob = RTUtils.Schlick(cosine, refIdx);
}
else
{
scattered = new Ray(new Point3D(rec.P.X, rec.P.Y, rec.P.Z), reflected);
reflect_prob = 1.0;
}
if (RTUtils.rd.NextDouble() < reflect_prob)
{
scattered = new Ray(new Point3D(rec.P.X, rec.P.Y, rec.P.Z), reflected);
}
else
{
scattered = new Ray(new Point3D(rec.P.X, rec.P.Y, rec.P.Z), refracted);
}
return(true);
}