public AntiIntersection AntiIntersect(Ray ray, SphereBase parentSphere)
{
Vector3 l = GetPosition() - ray.GetStart(); //Vector to sphere center (and direction)
float tc = Vector3.Dot(l, ray.GetDirection()); //Length to ray hit-center
float els = Vector3.Dot(l, l);
float radiusSquared = _radius * _radius;
if (tc < 0 && els > radiusSquared)
{
return(AntiIntersection.CreateNullAntiIntersection());
}
float dSquared = els - tc * tc; //Squared perpendicular distance from spherecenter to ray (vinkelrätt)
if (dSquared > radiusSquared)
{
return(AntiIntersection.CreateNullAntiIntersection());
}
float t1c = (float)Math.Sqrt(radiusSquared - dSquared);
float tNear, tFar;
tNear = tc - t1c;
tFar = tc + t1c;
Vector3 pNear = ray.GetStart() + Vector3.Multiply(ray.GetDirection(), tNear);
Vector3 pFar = ray.GetStart() + Vector3.Multiply(ray.GetDirection(), tFar);
var normNearTexture = Vector3.Normalize(Vector3.Divide(GetPosition() - pNear, _radius));
var normFarTexture = Vector3.Normalize(Vector3.Divide(GetPosition() - pFar, _radius));
return(new AntiIntersection(pNear, pFar, normNearTexture, normFarTexture, tNear, tFar, this));
}
public Intersection(Vector3 positionFirstHit, Vector3 normalFirstHit, Vector3 normalFirstHitTexture, float tFirstHit, float tNear, float tFar, SphereBase sphereBase)
{
_hasValue = true;
_positionFirstHit = positionFirstHit;
_normalFirstHit = normalFirstHit;
_normalFirstHitTexture = normalFirstHitTexture;
_tFirstHit = tFirstHit;
_tNear = tNear;
_tFar = tFar;
_sphereBase = sphereBase;
}
public Intersection(bool isNull)
{
_hasValue = !isNull;
_positionFirstHit = Vector3.Zero;
_normalFirstHit = Vector3.Zero;
_normalFirstHitTexture = Vector3.Zero;
_tFirstHit = float.MaxValue;
_tNear = float.MaxValue;
_tFar = float.MaxValue;
_sphereBase = null;
}
public AntiIntersection(Vector3 positionNear, Vector3 positionFar, Vector3 normalNearTexture, Vector3 normalFarTexture, float tNear, float tFar, SphereBase sphereBase)
{
_hasValue = true;
_isInfinite = false;
_positionNear = positionNear;
_positionFar = positionFar;
_normalNearTexture = normalNearTexture;
_normalFarTexture = normalFarTexture;
_tNear = tNear;
_tFar = tFar;
_sphereBase = sphereBase;
}
public AntiIntersection(bool isNull, bool isInfinite)
{
_hasValue = !isNull;
_isInfinite = isInfinite;
_positionNear = Vector3.Zero;
_positionFar = Vector3.Zero;
_normalNearTexture = Vector3.Zero;
_normalFarTexture = Vector3.Zero;
_tNear = float.MaxValue;
_tFar = float.MaxValue;
_sphereBase = null;
}
