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));
}
private AntiIntersection getFarthestAntiIntersection(float tMin, float tMax, AntiIntersection[] antiSphereIntersectionList)
{
AntiIntersection farthestAntiIntersection = AntiIntersection.CreateNullAntiIntersection();
tMin = (tMin < 0) ? 0 : tMin;
float tCurrent = tMin;
//compare the hits in the antilist
foreach (AntiIntersection antiIntersection in antiSphereIntersectionList)
{
//Break here, because the sorting places all the missed intersections in the end
if (!antiIntersection.IsHit())
{
break;
}
if (antiIntersection.isDistanceInside(tCurrent))
{
//Move away the nearest hit to the other side of the AntiSphere
tCurrent = antiIntersection.GetTFar();
farthestAntiIntersection = antiIntersection;
}
if (tCurrent >= tMax)
{
//It went through
farthestAntiIntersection = AntiIntersection.CreateInfiniteAntiIntersection();
break;
}
}
return(farthestAntiIntersection);
}
public AntiSphereAntiIntersection(AntiSphere antiSphere)
{
_antiSphere = antiSphere;
_antiIntersection = AntiIntersection.CreateNullAntiIntersection();
}
