public void Render(Scene scene)
{
double nx = buffer.width;
double ny = buffer.height;
var hdw = ny / nx;
var lowerLeft = new Vector3(-fov / 2f, -fov / 2f * hdw, 1f);
var horizon = Vector3.right * fov;
var vertical = Vector3.up * fov * hdw;
var origin = Vector3.zero;
//todo: tranform calculation here.
for (int k = 0; k < spp; k++)
{
for (int i = 0; i < nx; i++)
{
for (int j = 0; j < ny; j++)
{
var u = (i + CoreRandom.Sample()) / nx;
var v = (j + CoreRandom.Sample()) / ny;
Ray r = new Ray(origin, lowerLeft + u * horizon + v * vertical - origin, depth);
scene.ColorRay(r);
buffer.pixels[i, j] = (buffer.pixels[i, j] * k + r.color) / (k + 1);
}
}
}
}
public override bool Scatter(Vector3 normal, Ray ray)
{
Vector3 outwardNor;
double cos, niByNt, reflectProb;
var rDn = Vector3.Dot(ray.direction, normal);
if (rDn > 0)
{
outwardNor = normal * (-1f);
niByNt = reflectiveIdx;
cos = reflectiveIdx * rDn;
}
else
{
outwardNor = normal;
niByNt = 1 / reflectiveIdx;
cos = -rDn;
}
Vector3 refractedDir;
if (Vector3.Refract(ray.direction, outwardNor, niByNt, out refractedDir))
{
reflectProb = Schlik(cos);
ray.origin = ray.GetHitPiont();
ray.direction = CoreRandom.Sample() < reflectProb?Vector3.Reflect(ray.direction, normal) : refractedDir;
}
else
{
ray.origin = ray.GetHitPiont();
ray.direction = Vector3.Reflect(ray.direction, normal);
}
return(true);
}