Is there a way to mask seperate materials?

[zepic]

Let's say I'm painting a tire for a car.  I just want to do a basic rubber fill on the tire, and a metal fill for the hub cap. 

Next, I would want to just paint on the tire, then the metal hub cap. (with masks?)

Is there a way to do this?

[unity2k]

Right now the only way I found is to mask the items using "Quick Mask" - shortcut = T. Then using a combination of Alignment = UV and Size Space = Object (although you should try different combinations to see what works for you) you can mask off what you don't want to paint. Hit shortcut of "I" to invert the mask and paint the next piece.

[zepic]

When you say Alignment=UV, what do you mean?  Where's the option located?

[unity2k]

Look on the right column in the Tool panel, expand the Brush options so it displays Brush - advanced.