static Color RayColor(Ray r)
{
var t = HitSphere(new Vec3(0, 0, -1), 0.5f, r);
if (t > 0.0f)
{
var n = (r.at(t) - new Vec3(0, 0, -1));
n.Normalize();
return(new Color((n.x + 1) * 0.5f, (n.y + 1) * 0.5f, (n.z + 1) * 0.5f));
}
Vec3 normalizeDirection = r.direction;
normalizeDirection.Normalize();
t = 0.5f * (normalizeDirection.y + 1);
return(new Color(1.0f) * (1 - t) + new Color(0.5f, 0.7f, 1.0f) * t);
}