public override bool Hit(Ray r, float tMin, float tMax, ref HitRecord record)
{
Vec3f oc = r.Origin - Center;
float a = Vec3f.Dot(r.Direction, r.Direction);
float b = Vec3f.Dot(oc, r.Direction);
float c = Vec3f.Dot(oc, oc) - Radius * Radius;
float discriminant = b * b - a * c;
if (discriminant > 0)
{
float tempSqrt = MathF.Sqrt(b * b - a * c);
float temp = (-b - tempSqrt) / a;
if (temp < tMax && temp > tMin)
{
record.t = temp;
record.Point = r.PointAtParameter(record.t);
record.Normal = (record.Point - Center) / Radius;
record.Material = this.Material;
return(true);
}
temp = (-b + tempSqrt) / a;
if (temp < tMax && temp > tMin)
{
record.t = temp;
record.Point = r.PointAtParameter(record.t);
record.Normal = (record.Point - Center) / Radius;
record.Material = this.Material;
return(true);
}
}
return(false);
}
public abstract bool Scatter(Ray r, HitRecord rec, out Vec3f attenuation, out Ray Scattered, Random drand);
public static RayImage RenderParallelFor(int width, int height, int samples)
{
// creating image and storage.
var img = new RayImage();
img.Width = width;
img.Height = height;
img.Pixels = new Rgb3f[width * height];
// setting up camera:
var lookFrom = new Vec3f(5f, 5f, 5f);
var lookAt = new Vec3f(0, 0, -1f);
float dist_to_focus = (lookFrom - lookAt).GetLength();
float aperture = 2.0f;
var cam = new Camera(lookFrom, lookAt, Vec3f.UnitY,
40, (float)width / (float)height, aperture, dist_to_focus);
var wrand = new Random();
var world = RandomScene(wrand);
// creating world.
//var world = new HitableList(
// new Sphere(new Vec3f(0f, 0f, -1f), 0.5f, new Lambertian(new Vec3f(0.1f, 0.2f, 0.5f))),
// new Sphere(new Vec3f(0, -100.5f, -1f), 100, new Lambertian(new Vec3f(0.8f, 0.8f, 0.0f))),
// new Sphere(new Vec3f(1f, 0f, -1f), 0.5f, new Metal(new Vec3f(0.8f, 0.6f, 0.2f), 0.0f)),
// new Sphere(new Vec3f(-1f, 0f, -1f), 0.5f, new Dielectric(1.5f)),
// new Sphere(new Vec3f(-1f, 0f, -1f), -0.45f, new Dielectric(1.5f))
// );
// looping height lines.
Parallel.For(0, height - 1, (cur) => {
var j = height - cur - 1; // invert it?
int curLine = cur * width;
var drand = new Random(); // create unique random object for each thread to prevent locking.
for (int i = 0; i < width; i++)
{
Vec3f col = Vec3f.Zero;
for (int s = 0; s < samples; s++)
{
float u = (float)(i + drand.NextDouble()) / (float)width;
float v = (float)(j + drand.NextDouble()) / (float)height;
Ray r = cam.GetRay(u, v, drand);
//Vec3f p = r.PointAtParameter(2.0f); // still not used.
col += Color(r, world, 0, drand);
}
col /= (float)samples;
col = new Vec3f(MathF.Sqrt(col.X), MathF.Sqrt(col.Y), MathF.Sqrt(col.Z));
img.Pixels[curLine + i] = (Rgb3f)col;
//img.Pixels[curLine + i] = new Rgb3f(0.3f, 0.4f, 0.6f);
}
//System.Threading.Thread.Sleep(5);
});
return(img);
}
public Ray(Vec3f o, Vec3f d)
{
this.Origin = o;
this.Direction = d;
}
public Metal(Vec3f a, float fuzz)
{
this.Albedo = a;
this.Fuzz = fuzz < 1 ? fuzz : 1.0f;
}
public Sphere(Vec3f center, float r, MaterialBase m)
{
this.Center = center;
this.Radius = r;
this.Material = m;
}
public Lambertian(Vec3f a)
{
this.Albedo = a;
}
public static Vec3f Reflect(Vec3f v, Vec3f n)
{
return(v - 2 * Dot(v, n) * n);
}
public static float Dot(Vec3f l, Vec3f r)
{
return(l.X * r.X + l.Y * r.Y + l.Z * r.Z);
}
public Vec3f Cross(Vec3f v)
{
return(Cross(this, v));
}
public float Dot(Vec3f v)
{
return(Dot(this, v));
}
