Variable surface texture on a translucent object

[lolbroklol]

Hi, all.

I've been working with rhino and v ray now for about two months. My first big model has been parts for a gun called the FN PS90. Below I have a rendered image of the magazine from the gun.

As you may be able to see, there is a noise texture all over the magazine, just as there is in real life. There are supposed to be, however, very smooth shiny parts where air was evacuated from the mold. So in some areas of the magazine, there is a noise texture, while the text and ribs across the top are supposed to be really shiny.

How can I accomplish this in V-Ray? Since its a translucent object, it has to be joined (as best as I can tell), so I can't apply a different material to different parts of the object, because when I join them, it chooses one of the materials to go with.

Also, what should I set the IOR at in order to make it look more plastic like?

Thanks.

http://img35.imageshack.us/img35/6647/magtest005.png

[dalomar_cg]

Re: Variable surface texture on a translucent object

The issue with any sort of refractive object is that there has to be an entrance and an exit surface. Typically this does mean that the object needs to be joined, but this is not always the case. In your case, I would say that if you extract the parts of the casing that you would like to be shiny, and kept the materials as similar as possible (minus the noise map obviously). I think since you will still have the correct entrance and exit surfaces you shouldn't really have that much of a problem.

In regards to plastic IORs those are typically lower than glass @ about 1.3 to 1.45.