Mesh Colliders

Is there an option to put a mesh collider (like in unity) on something vs box/sphere etc collider.

For example I have a mesh of a 4 sided wall all combined as one mesh. If I put a box collider on it then obviously nothing can exist inside of it and it would block any door ways. I would like the collider to form to the mesh.

Yes, you need to do it in your modeling program:

In blender, I just copy my model, simplify it (optional), and then name the model used for collision according to the rules set forth in the link above. (Basically, if your model is named “thing” name your collision model “UCX_thing”)