maya rendering patches


#1

I’ve modeled a rough set for a project I’m doing, and this happened.

http://imgur.com/8XHk0uh

I’ve imported the same model to maya windows, and everything is fixed when I change the primary renderer to Scanline. I’m currently using maya 2013, mental ray on os x. Does anyone know why this happens and how to fix this?

Additional Information :
Double sided turned off
2 Lights - 1 Directional and 1 Ambient (0 ambient shade)
No double planing

The problems are shaded in red btw.