public bool Hit(MyRay _ray, float _tmin, float _tmax, HitInfo _hitInfo)
{
Vector3 oc = _ray.Origin - Center;
float a = Vector3.Dot(_ray.Direction, _ray.Direction);
float b = 2f * Vector3.Dot(oc, _ray.Direction);
float c = Vector3.Dot(oc, oc) - Radius * Radius;
float discriminant = b * b - 4 * a * c;
if (discriminant > 0)
{
float t = (-b - Mathf.Sqrt(discriminant)) / (2 * a);
if (t > _tmin && t < _tmax)
{
_hitInfo.T = t;
_hitInfo.HitPoint = _ray.PointAtT(t);
_hitInfo.Normal = (_hitInfo.HitPoint - Center) / Radius;
_hitInfo.Material = Material;
return(true);
}
t = (-b + Mathf.Sqrt(discriminant)) / (2 * a);
if (t > _tmin && t < _tmax)
{
_hitInfo.T = t;
_hitInfo.HitPoint = _ray.PointAtT(t);
_hitInfo.Normal = (_hitInfo.HitPoint - Center) / Radius;
_hitInfo.Material = Material;
return(true);
}
}
return(false);
}
private Color GetColor(MyRay _ray)
{
float t = HitSphere(new Vector3(0, 0, -1), 0.5f, _ray);
if (t > 0)
{
Vector3 normal = _ray.PointAtT(t) - new Vector3(0, 0, -1);
Vector3 normalAsRGB = 0.5f * (normal + Vector3.one);
return(new Color(normalAsRGB.x, normalAsRGB.y, normalAsRGB.z));
}
return(GetBackgroundColor(_ray));
}