new render
I did a couple of tests for rendering
This is a render from mental ray

the stroke rendered under maya software

composed in photoshop

Here's the result from maya software (I adjusted the camera angle to fit into the 2D animation)

The maya software works better with my 2D elements because it gives less gradient on the surfaces, plus it's much faster. I think this is the render methodology that I'm going to follow for most part of the project.
This is a render from mental ray

the stroke rendered under maya software

composed in photoshop

Here's the result from maya software (I adjusted the camera angle to fit into the 2D animation)

The maya software works better with my 2D elements because it gives less gradient on the surfaces, plus it's much faster. I think this is the render methodology that I'm going to follow for most part of the project.