Digieffects Atmosphere
The Atmosphere plugin for After Effects realistically simulates atmospheric conditions such as haze and fog in your composition.
Layers further away from the camera appear to be more deeply immersed in the haze/fog than layers closer to the camera. This also applies to parts of layers: If one edge or area of a layer is closer to the camera, this area will appear less immersed in the haze/fog than the pixels further away. You can simulate very realistic or very unrealistic types of atmospheric effects using the Atmosphere plugin.
The strength of the atmosphere plug-in doesn’t shine in a single-layer comp. Much like our falloff lighting plug, you get the full benefit when working in after effect’s 3D mode and have multiple layers with different Z-depths, atmosphere will apply the fog effect differently depending on lighting and distance to the camera.