Shadows appear from inside objects

[stellaaash]

With the current way shadows are calculated, if you place the camera inside of an object, you will see the shadows cast on it by other objects:

Scene presented here:

[stellaaash]

This shouldn't be TOO hard to fix, but I'm waiting for us to have a more finished product to fix that one since it's not really a major bug.

Ways to fix that

• Find the cosine between:
  • The vector from the camera to that point on the sphere's inside
  • The normal of the sphere
• If it's lower than 0, it means we're looking from below the surface of the sphere.
• Now we check another cosine between:
  • The normal of the sphere (again)
  • The vector of shadow going to the point of the sphere from another object
• If that one is also below 0, it means the shadow is also below the surface, and we can render it. Otherwise, no shadow will be seen (because it will only be above the surface of the sphere).