Even-odd test with raycasting

An easy way to determine if a point is inside a finite, closed shape is to cast a ray and count how many times it intersects the surface. If it's odd, the point is inside. If it's even, the point was outside.

The proof is trivial. If a point in a finite closed shape moves along a ray, any time it passes through the surface it switches between being inside or outside the object.

A naive approach to solving this would be to run a ray from a point outward, store the point, and continue - toggling an odd/even Boolean each time. The problem is that rays in Unity can't intersect a Collider when coming from the inside. According to the Physics.Raycast() documentation.

Notes: Raycasts will not detect Colliders for which the Raycast origin is inside the Collider.

Well, that's fun. So what now?

EDIT

Based off Bunny83's helpful insights, I was able to solve the problem. Here is the code for anyone in the future who comes across this question:

 private bool HasOddParity(Collider collider, Vector3 point)
 {
     float magnitude = collider.bounds.size.magnitude * 2;
     bool odd = false;
 
     Vector3 outward = new Vector3 (1, 0, 0);
     Vector3 inward = new Vector3(-1, 0, 0);
     Ray currentRay = new Ray(point, outward);
     RaycastHit hit;
 
     //Near cast
     while (collider.Raycast(currentRay, out hit, magnitude))
     {
         odd = !odd;
         currentRay = new Ray(hit.point, outward);
     }
 
     Vector3 farPoint = Vector3.MoveTowards(currentRay.origin, currentRay.origin + (outward * magnitude), magnitude);
     currentRay = new Ray(farPoint, inward);
 
     //Far cast
     while (collider.Raycast(currentRay, out hit, magnitude))
     {
         if (hit.point.x > point.x)
         {
             odd = !odd;
             currentRay = new Ray(hit.point, inward);
         }
         else break;
     }
 
     return odd;
 }