One thing you can do:
Window -> Rendering Editors -> Render Settings
Then change the default renderer to Maya Vector.
Change the file extension to .png (it has automatic transparency)
Go to the Maya Vector tab (not the common tab) and then:
Open up "Edge Options" menu.
Check "Include Edges"
Play around with the options you have.
Render the edges, then render the image with maya software/mentalray, and then composite in Photoshop/GIMP (the later being free software)
Btw, hi guys...I guess it's been a very (very) long time since I was on here.