public static Vector3 RandomInUnitSphere(this ImSoRandom random)
{
var p = new Vector3();
do
{
p = 2.0f * new Vector3(random.NextFloat(), random.NextFloat(), random.NextFloat()) - new Vector3(1, 1, 1);
} while (p.LengthSquared() >= 1.0f);
return(p);
}
public static Vector3 RandomInUnitDisk(this ImSoRandom random)
{
var p = new Vector3();
do
{
p = 2.0f * new Vector3(random.NextFloat(), random.NextFloat(), 0) - new Vector3(1, 1, 0);
} while (Vector3.Dot(p, p) >= 1.0f);
return(p);
}
public static (List <IHitable>, Camera) RandomScene(ImSoRandom rnd, int nx, int ny)
{
var world = new List <IHitable>();
var texture = new CheckerTexture(new ConstantTexture(0.2f, 0.3f, 0.1f), new ConstantTexture(0.9f, 0.9f, 0.9f));
world.Add(new Sphere(new Vector3(0, -1000f, 0), 1000, new Lambertian(texture)));
for (int a = -11; a < 11; a++)
{
for (int b = -11; b < 11; b++)
{
float choose_mat = rnd.NextFloat();
var center = new Vector3(a + 0.9f * rnd.NextFloat(), 0.2f, b + 0.9f * rnd.NextFloat());
if ((center - new Vector3(4, 0.2f, 0)).Length() > 0.9)
{
if (choose_mat < 0.8)
{ // diffuse
world.Add(new MovingSphere(center, center + new Vector3(0, 0.5f * rnd.NextFloat(), 0), 0.0f, 1.0f, 0.2f, new Lambertian(new ConstantTexture(rnd.NextFloat() * rnd.NextFloat(), rnd.NextFloat() * rnd.NextFloat(), rnd.NextFloat() * rnd.NextFloat()))));
//world.Add(new Sphere(center, 0.2f, new Lambertian(new Vector3(rnd.NextFloat() * rnd.NextFloat(), rnd.NextFloat() * rnd.NextFloat(), rnd.NextFloat() * rnd.NextFloat()))));
}
else if (choose_mat < 0.95)
{ // metal
world.Add(new Sphere(center, 0.2f,
new Metal(new Vector3(0.5f * (1 + rnd.NextFloat()), 0.5f * (1 + rnd.NextFloat()), 0.5f * (1 + rnd.NextFloat())), 0.5f * rnd.NextFloat())));
}
else
{ // glass
world.Add(new Sphere(center, 0.2f, new Dialectric(1.5f)));
}
}
}
}
world.Add(new Sphere(new Vector3(0, 1, 0), 1.0f, new Dialectric(1.5f)));
world.Add(new Sphere(new Vector3(-4, 1, 0), 1.0f, new Lambertian(new ConstantTexture(0.4f, 0.2f, 0.1f))));
world.Add(new Sphere(new Vector3(4, 1, 0), 1.0f, new Metal(new Vector3(0.7f, 0.6f, 0.5f), 0f)));
world.Add(new Sphere(new Vector3(0, 0, 0), 20.0f, new DiffuseLight(new ConstantTexture(new Vector3(1, 1, 1)))));
var lookFrom = new Vector3(13, 2, 3);
var lookAt = new Vector3(0, 0, 0);
var distToFocus = 10;
var aperture = 0.1f;
var cam = new Camera(lookFrom, lookAt, new Vector3(0, 1, 0), 20, (float)nx / (float)ny, aperture, distToFocus, 0.0f, 1.0f);
return(world, cam);
}
public Ray GetRay(float u, float v, ImSoRandom rnd)
{
var rd = LensRadius * rnd.RandomInUnitDisk();
var offset = U * rd.X + V * rd.Y;
float time = Time0 + rnd.NextFloat() * (Time1 - Time0);
return(new Ray(Origin + offset, LowerLeftCorner + u * Horizontal + v * Vertical - Origin - offset, time));
}
public static (List <IHitable>, Camera) PoolScene(ImSoRandom rnd, int nx, int ny)
{
var world = new List <IHitable>();
world.Add(new Sphere(new Vector3(0, -1000f, 0), 1000, new Lambertian(new ConstantTexture(0.33f, 0.67f, 0.0f))));
var red = new ConstantTexture(0.68f, 0.13f, 0.16f);
var yellow = new ConstantTexture(1f, 0.74f, 0.13f);
var black = new ConstantTexture(0.14f, 0.07f, 0.07f);
var white = new ConstantTexture(1f, 1f, 0.9f);
for (var a = 1f; a <= 5; a += 1f)
{
var counter = 0 - a;
for (var b = 0f; b < a; b += 1f)
{
var center = new Vector3(a * 0.9f - 5f, 0.5f, a / 2f - b - 0.5f);
var colour = counter % 2 == 0 ? red : yellow;
if (a == 3 && b == 1)
{
colour = black;
}
if (a == 3 && b == 2)
{
colour = red;
}
if (a == 5 && b == 4)
{
colour = red;
}
world.Add(new Sphere(center, 0.45f,
new Lambertian(colour)));
world.Add(new Sphere(center, 0.5f,
new Dialectric(1.5f)));
counter++;
}
}
var cueCenter = new Vector3(-6, 0.5f, 0);
var cueCenter1 = cueCenter + new Vector3(0.75f * rnd.NextFloat(), 0, 0);
world.Add(new MovingSphere(cueCenter, cueCenter1, 0.0f, 1.0f, 0.5f,
new Dialectric(1.5f)));
world.Add(new MovingSphere(cueCenter, cueCenter1, 0.0f, 1.0f, 0.45f,
new Lambertian(white)));
world.Add(new RectXZ(-3, 3, -2, 2, 5, new DiffuseLight(new ConstantTexture(new Vector3(15, 15, 15)))));
var lookFrom = new Vector3(-9, 3.5f, 12);
var lookAt = new Vector3(-3, 0, 0);
var distToFocus = (lookFrom - new Vector3(-6, 0.5f, 0)).Length();
var aperture = 0.5f;
var cam = new Camera(lookFrom, lookAt, new Vector3(0, 1, 0), 20, (float)nx / (float)ny, aperture, distToFocus, 0.0f, 1.0f);
return(world, cam);
}
private static void RenderRow(Image <Rgba32> image, IHitable[] wl, Camera cam, int j, int nx, int ny, int ns, ImSoRandom rnd, ConcurrentDictionary <int, int> processedRows, ref uint rayCount)
{
var index = ny - 1 - j;
var rowSpan = image.GetPixelRowSpan(index);
for (int i = 0; i < nx; i++)
{
var col = new Vector3(0);
for (var s = 0; s < ns; s++)
{
float u = ((float)i + rnd.NextFloat()) / (float)nx;
float v = ((float)j + rnd.NextFloat()) / (float)ny;
var r = cam.GetRay(u, v, rnd);
col += Color(r, wl, 0, rnd, ref rayCount);
}
col /= (float)ns;
col = new Vector3((float)Math.Sqrt(col.X), (float)Math.Sqrt(col.Y), (float)Math.Sqrt(col.Z));
rowSpan[i] = new Rgba32(col);
}
processedRows.TryAdd(j, Thread.CurrentThread.ManagedThreadId);
}
public override bool Scatter(Ray rayIn, HitRecord rec, out Vector3 attenuation, out Ray scattererd, ImSoRandom random)
{
Vector3 reflected = Vector3.Reflect(rayIn.Direction, rec.Normal);
attenuation = new Vector3(1.0f);
Vector3 outward_normal;
float niOverNt;
float cosine;
if (Vector3.Dot(rayIn.Direction, rec.Normal) > 0)
{
outward_normal = -rec.Normal;
niOverNt = _refIndex;
cosine = _refIndex * Vector3.Dot(rayIn.Direction, rec.Normal) / rayIn.Direction.Length();
}
else
{
outward_normal = rec.Normal;
niOverNt = 1.0f / _refIndex;
cosine = -Vector3.Dot(rayIn.Direction, rec.Normal) / rayIn.Direction.Length();
}
Vector3 refracted;
float reflectProb;
if (Refract(rayIn.Direction, outward_normal, niOverNt, out refracted))
{
reflectProb = Schlick(cosine, _refIndex);
}
else
{
reflectProb = 1.0f;
}
if (random.NextFloat() < reflectProb)
{
scattererd = new Ray(rec.P, reflected, rayIn.Time);
}
else
{
scattererd = new Ray(rec.P, refracted, rayIn.Time);
}
return(true);
}
public static Vector3 RandomVector(this ImSoRandom random)
{
return(new Vector3(10 + random.NextFloat() * 400f, 10 + random.NextFloat() * 400f, 10 + random.NextFloat() * 400f));
}