OpenGL: lighting inside a cube

Question

I create a scene in which I use the field to represent the room and the different models in this field. When I turn on the lights, my models light up well, but the room itself (inside the box) does not light up, or rather, it is darker than it should be. Is it because I'm trying to light inside a cube? I am sure the normals are correct. Please let me know what you think!

I suppose the normals are wrong, but how can I find the right normals for inside the cube. Currently, I pass only the center point of each face to normal function.

Answer 1

If you walk in the center, your normals will encounter the wrong way.

, 2 , X (1, 0, 0), .

, , , , .. (-1, 0, 0).