real fog?

[revenicus 0]

Here's the thing I wanted to make a mission in the morning, where there is fog. the problem is the skybox shows through up top no matter how much fog you have.

I remember making a map for vietcong and this problem was also there, but there was a setting to adjust fog for the skybox. I need it so when you look up you don't see blue sky or moving clouds, because with proper fog, you shouldn't be able to see through it to the sky.