public override Intersection Intersect(Ray ray)
{
double a = ray.Direction.Dot(Point);
if (Math.Abs(a - 0d) < 0.01d)
{
return(new Intersection());
}
double t = Point.Dot(ray.Point.Add(-Point.Mult(Distance)));
Vector point = ray.PointAt(t);
return(new Intersection(t, point, this.point, material));
}
public override Intersection Intersect(Ray ray)
{
Vector diff = this.point - ray.Point;
double b = diff.Dot(ray.Direction);
double determinant = (b * b) - diff.Dot(diff) + radiusSquared;
if (determinant < 0.0)
{
return(new Intersection());
}
else
{
double detSqrt = Math.Sqrt(determinant);
double b1 = b - detSqrt;
double b2 = b + detSqrt;
double t = (b1 > Vector.EPSILON) ? b1 :
((b2 > Vector.EPSILON) ? b2 : Intersection.MaxT);
Vector point = ray.PointAt(t);
Vector normal = (point - this.point) * radiusRecip;
return(new Intersection(t, point, normal, material));
}
}
public static bool Hit(Sphere sphere, Ray ray, float tMin, float tMax, out RayHit hit)
{
Vector3 center = sphere.Center;
Vector3 oc = ray.Origin - center;
Vector3 rayDir = ray.Direction;
float a = Vector3.Dot(rayDir, rayDir);
float b = Vector3.Dot(oc, rayDir);
float radius = sphere.Radius;
float c = Vector3.Dot(oc, oc) - radius * radius;
float discriminant = b * b - a * c;
if (discriminant > 0)
{
float tmp = MathF.Sqrt(b * b - a * c);
float t = (-b - tmp) / a;
if (t < tMax && t > tMin)
{
Vector3 position = Ray.PointAt(ray, t);
Vector3 normal = (position - center) / radius;
hit = RayHit.Create(Ray.PointAt(ray, t), t, normal);
return(true);
}
t = (-b + tmp) / a;
if (t < tMax && t > tMin)
{
Vector3 position = Ray.PointAt(ray, t);
Vector3 normal = (position - center) / radius;
hit = RayHit.Create(position, t, normal);
return(true);
}
}
hit.Position = new Vector3();
hit.Normal = new Vector3();
hit.T = 0;
return(false);
}
public override Intersection Intersect(Ray ray)
{
double nMinX, nMinY, nMinZ, nMaxX, nMaxY, nMaxZ;
double tMin, tMax;
double tX1 = (-Width + this.point.X - ray.Point.X) / ray.Direction.X;
double tX2 = (Width + this.point.X - ray.Point.X) / ray.Direction.X;
if (tX1 < tX2)
{
tMin = tX1;
tMax = tX2;
nMinX = -Width;
nMinY = 0.0;
nMinZ = 0.0;
nMaxX = Width;
nMaxY = 0.0;
nMaxZ = 0.0;
}
else
{
tMin = tX2;
tMax = tX1;
nMinX = Width;
nMinY = 0.0;
nMinZ = 0.0;
nMaxX = -Width;
nMaxY = 0.0;
nMaxZ = 0.0;
}
if (tMin > tMax)
{
return(new Intersection());
}
double tY1 = (-Height + this.point.Y - ray.Point.Y) / ray.Direction.Y;
double tY2 = (Height + this.point.Y - ray.Point.Y) / ray.Direction.Y;
if (tY1 < tY2)
{
if (tY1 > tMin)
{
tMin = tY1;
nMinX = 0.0;
nMinY = -Height;
nMinZ = 0.0;
}
if (tY2 < tMax)
{
tMax = tY2;
nMaxX = 0.0;
nMaxY = Height;
nMaxZ = 0.0;
}
}
else
{
if (tY2 > tMin)
{
tMin = tY2;
nMinX = 0.0;
nMinY = Height;
nMinZ = 0.0;
}
if (tY1 < tMax)
{
tMax = tY1;
nMaxX = 0.0;
nMaxY = -Height;
nMaxZ = 0.0;
}
}
if (tMin > tMax)
{
return(new Intersection());
}
double tZ1 = (-Depth + this.point.Z - ray.Point.Z) / ray.Direction.Z;
double tZ2 = (Depth + this.point.Z - ray.Point.Z) / ray.Direction.Z;
if (tZ1 < tZ2)
{
if (tZ1 > tMin)
{
tMin = tZ1;
nMinX = 0.0;
nMinY = 0.0;
nMinZ = -Depth;
}
if (tZ2 < tMax)
{
tMax = tZ2;
nMaxX = 0.0;
nMaxY = 0.0;
nMaxZ = Depth;
}
}
else
{
if (tZ2 > tMin)
{
tMin = tZ2;
nMinX = 0.0;
nMinY = 0.0;
nMinZ = Depth;
}
if (tZ1 < tMax)
{
tMax = tZ1;
nMaxX = 0.0;
nMaxY = 0.0;
nMaxZ = -Depth;
}
}
if (tMin > tMax)
{
return(new Intersection());
}
if (tMin < 0.0)
{
tMin = tMax;
nMinX = nMaxX;
nMinY = nMaxY;
nMinZ = nMaxZ;
}
if (tMin >= 0.0)
{
double t = tMin;
Vector point = ray.PointAt(t);
Vector normal = new Vector(nMinX, nMinY, nMinZ).Normalized;
return(new Intersection(t, point, normal, this.material));
}
else
{
return(new Intersection());
}
}