There are 4 types of post effects;
- DistortionPostEffect - I have no idea what this does.
BloomPostEffect - This is self explanatory, if you don't know what it is turn it on and play with the values.
LookupTablePostEffect - This is similar to Bloom, although more about overall light exposure than "blooms". In order to get this working though (it'll initially be turned on showing the entire map with a pink overlay) you need to have a file named "BleachByPass_vol.tga". You can download that tga (as well as the one for LightRays) here.
Where you download and extract the file to doesn't matter.
Now when you click the "volume texture" select the "BleachByPass_vol.tga" file, and then scale the slider to whichever value works best (I'd suggest something low for starters).
Here is an image of one of the settings from one of the C&C3 Red Zone maps;
LightRaysPostEffects - This is used for the sunlight poking through the clouds on Red Zone maps. Like the lookuptable, this also requires a tga which you can get from here (its included in with the LookupTable tga I posted earlier). This tga is named "CM_RedZoneA_LightRays" and as with the previous, it doesn't matter where the file is actually located.
Again here is an image showing the settings EA used for Red Zone maps;