Fog question for all who can help...

[Mad Baron]

Are there different degrees/extremes of rain? My cmbb only has these:
>>Rain
>>Fog and Rain
And I assumed (never tried it) it was the same level of rain for both, just with fog thrown in for the 2nd one.

My fog settings are:
>>Fog and Rain
>>Fog
>>Thick Fog

I have never been able to see fog in any CM game (even through 3 different pc's now since I first got the games), and always thought it would be a neat visual, since the cmbo opening video does show one fog-covered wooded area with troops on the move through it. But game-wise, I never see fog; only the limited visability is applied to the unit capabilities.