public override bool DistanceToRay(Ray ray, HitResult result)
{
var pos = Transform.Translation;
float a = VMath.Dot(ray.vec, pos - ray.pos);
float e = (pos - ray.pos).LengthSquare();
float f = Range * Range - e + a * a;
if (f < 0)
{
return(false);
}
float distance = a - (float)Math.Sqrt(f);
if (result.distance > distance && distance > 0.05)
{
result.normal = VMath.Normalize((ray.pos + ray.vec * distance) - pos);
result.material = Material;
result.distance = distance;
return(true);
}
else
{
return(false);
}
}
public Vector3 RandomCosineDirection()
{
double r1 = Rand.NextDouble();
double r2 = Rand.NextDouble();
float z = (float)Math.Sqrt(1 - r2);
double phi = Math.PI * 2 * r1;
float x = (float)(Math.Cos(phi) * Math.Sqrt(r2));
float y = (float)(Math.Sin(phi) * Math.Sqrt(r2));
return(VMath.Normalize(new Vector3(x, y, z)));
}
protected Vector3 CreateReflectedVector(Ray ray, Vector3 normal, Vector3 pos)
{
if (Rand.NextDouble() < Roughness)
{
var vec = new Vector3((float)Rand.NextDouble() * 0.5F - 0.25F, 3, (float)Rand.NextDouble() * 0.5F - 0.25F) - pos;
if (VMath.Dot(vec, normal) > 0)
{
return(VMath.Normalize(vec));
}
}
return(Vector3.Interpolate(Reflect(ray.vec, normal), RandomCosineDirection() * Matrix3.LookAt(normal, RandomCosineDirection()), Roughness));
}
public bool IsIntersectWithRay(Ray ray)
{
var target = Pos - ray.pos;
float time = VMath.Dot(VMath.Normalize(ray.vec), target);
if (time <= 0)
{
return(false);
}
float distance = target.LengthSquare() - time * time;
return(distance <= Range * Range);
}
public Vector3 Reflect(Vector3 vec, Vector3 nornal)
{
return(VMath.Normalize(vec - 2 * VMath.Dot(vec, nornal) * nornal));
}