public Ray GetRay(float s, float t)
{
var temp = MathR.RandomPointInDisc() * LensRadius;
var apertureOffset = (U * temp.X) + (V * temp.Y);
return(new Ray(Origin + apertureOffset, LowerLeftCorner + (U * s * 2 * HalfWidth) + (V * t * 2 * HalfHeight) - (Origin + apertureOffset)));
}
public static Vec3 Refract(this Vec3 uv, Vec3 n, float etaiOverEtat)
{
var cosTheta = Math.Min(-MathR.Dot(uv, n), 1);
var rOutParallel = (uv + (n * cosTheta)) * etaiOverEtat;
var rOutPerpendicular = n * -MathF.Sqrt(1 - Math.Min(rOutParallel.SquareLenght(), 1));
return(rOutPerpendicular + rOutParallel);
}
public static byte FinalizeColor(float pixelColor, int samplesPerPixel)
{
var c = pixelColor;
// Replace NaN components with zero. See explanation in Ray Tracing: The Rest of Your Life.
if (float.IsNaN(c))
{
c = 0.0f;
}
// Divide the color by the number of samples and gamma-correct for gamma=2.0.
var scale = 1.0f / samplesPerPixel;
c = MathF.Sqrt(scale * c);
// return the translated [0,255] value of each color component.
return(Convert.ToByte(255 * MathR.Clamp(c, 0.0f, 0.999f)));
}
public Camera(Vec3 origin, Vec3 lookAt, Vec3 vUp, float fovY, float aspectRatio, float aperture, float distToFocus) : this()
{
Origin = origin;
LookAt = lookAt;
VecUp = vUp;
DistToFocus = distToFocus;
AspectRatio = aspectRatio;
FovY = MathR.ConvertDegreesToRadians(fovY);
LensRadius = aperture / 2;
HalfHeight = MathF.Tan(FovY / 2) * DistToFocus;
HalfWidth = HalfHeight * AspectRatio;
W = MathR.Normalize(LookAt - Origin);
U = MathR.Normalize(MathR.Cross(W, vUp));
V = MathR.Cross(U, W);
LowerLeftCorner = Origin + (W * DistToFocus) - (V * HalfHeight) - (U * HalfWidth);
}
public Vec3 GetColor(Ray ray, HitableList scene, int depth)
{
if (depth == 0)
{
return(new Vec3(0, 0, 0));
}
var hit = scene.GetNearestHit(ray, 0.0001F);
if (hit != null)
{
var result = hit.Material.Scatter(ray, hit);
if (result != default)
{
return(GetColor(result.ray, scene, depth - 1) * result.color);
}
}
var t = (MathR.Normalize(ray.Direction).Y + 1) * 0.5F;
return((new Vec3(1, 1, 1) * (1.0F - t)) + (new Vec3(0.5F, 0.7F, 1) * t));
}
public static byte[] FinalizeColor(Vec3 pixelColor, int samplesPerPixel)
{
(var r, var g, var b) = pixelColor;
// Replace NaN components with zero. See explanation in Ray Tracing: The Rest of Your Life.
//if (r != r) r = 0.0f;
//if (g != g) g = 0.0f;
//if (b != b) b = 0.0f;
// Divide the color by the number of samples and gamma-correct for gamma=2.0.
var scale = 1.0f / samplesPerPixel;
r = MathF.Sqrt(scale * r);
g = MathF.Sqrt(scale * g);
b = MathF.Sqrt(scale * b);
// return the translated [0,255] value of each color component.
return(new[] {
Convert.ToByte(255 * MathR.Clamp(r, 0.0f, 0.999f)),
Convert.ToByte(255 * MathR.Clamp(g, 0.0f, 0.999f)),
Convert.ToByte(255 * MathR.Clamp(b, 0.0f, 0.999f))
});
}
