I've recently made the switch from Cinema 4d to Maya and so far the only thing I'm struggling to find the equivelent replacement for is Cinema's infinity plane and background object (useful for placing horizon/sky objects into a scene). I'm also used to environmental fog being attached to cinemas ambient lighting (environment) but haven't found it yet. Can anyone point me in the right direction?
There isn't an infinite plane in maya, so you'll have to scale geometry up real large.
As for the environment with the maya renderer selected go to render globals and select the maya tab. Expand the Render Options frame. you should see environment fog there. click the texture button next to the text field and it will connect it automatically for you.
Now I can't seem to find an equivilant field on the mental ray render globals but it seems if you connect the environment fog in the maya render globals it renders when you switch to mental ray also.
In mental ray you can map an environment map to the camera (select camera and expand mental ray frame). Then you will have an infinite environment.
Might also be possible to write a mel script that will somehow create the illusion of an infinite plane... i don't know mel all that well but maybe someone has already written one, check google or highend3d.com