public bool TryIntersect(
Ray3 ray,
double tmin,
double tmax,
out ShadeRecord sr)
{
sr = null;
var oc = ray.Origin - this.center;
var a = Vector3.MagnitudeSquared(ray.Direction);
var halfB = Vector3.Dot(oc, ray.Direction);
var c = Vector3.MagnitudeSquared(oc) - this.radius * this.radius;
var discriminant = halfB * halfB - a * c;
if (discriminant < 0)
{
return(false);
}
var sqrtd = Math.Sqrt(discriminant);
var root = (-halfB - sqrtd) / a;
if (root < tmin || tmax < root)
{
root = (-halfB + sqrtd) / a;
if (root < tmin || tmax < root)
{
return(false);
}
}
ShadeRecord CreateShadeRecord(double t)
{
var p = ray.GetPosition(t);
var n = (p - this.center) / this.radius;
var sr = new ShadeRecord
{
Point = p,
T = t,
Material = this.material,
};
sr.SetFaceNormal(ray, (Normal3)n);
return(sr);
}
sr = CreateShadeRecord(root);
return(true);
}