Yesterday I had  a look into Carrara 6 pro. I tried some of our mesh. First problem came up in changing unit (in) into (pixel) in vertex modeller. I moved into

Preferences -> General Scene Settings -> 3D Unit System 

but found no item like    pixel, mm, m etc...

Question: How can I change into pixel? We are interested in buying carrara but want to be sure everything is working fine.

Daniel + Matthias