Vray Environment fog and Alpha channel

[CG_Utopian]

Hey Guys,

I am having an issue with my alpha pass which is being affected by the environment fog in the scene, once i enable the fog everything black in the alpha pass turns into grey. so just wondering is there a way to make vray fog not affect the alpha pass?

Thanks

[Svetlozar Draganov]

Affect Background option does that but it will also remove the Fog from the Environment in the RGB channel which you probably don't want.
If you would like to keep the Fog into the environment and to remove it only from the Alpha it would be better to split to the Fog into a separate render-pass.