public override bool Hit(Ray r, double tmin, double tmax, ref HitRecord rec)
{
Vec oc = r.Origin - _center;
double a = r.Direction.Dot(r.Direction);
double b = oc.Dot(r.Direction);
double c = oc.Dot(oc) - _radius * _radius;
double discriminant = b * b - a * c;
if (discriminant < 0)
{
return(false);
}
double sqrtd = Math.Sqrt(discriminant);
// Find the nearest root that lies in the acceptable range.
double root = (-b - sqrtd) / a;
if (root < tmin || tmax < root)
{
root = (-b + sqrtd) / a;
if (root < tmin || tmax < root)
{
return(false);
}
}
rec.Material = _mat;
rec.t = root;
rec.P = r.PointAtParameter(rec.t);
Vec outwardNormal = (rec.P - _center) / _radius;
rec.SetFaceNormal(r, outwardNormal);
return(true);
}
public virtual bool Hit(Ray r, double tmin, double tmax, ref HitRecord rec) => false;