Aluminium material : Vray

well its fairly simple to set up...
get the aluminium colour from an image.......


so make the vray mat the same colour as the image .. you can do this by going to File, then View image file... then you can right click on the image and you are able to get the correct colour of the image.

Then you can drag and drop that colour to your materail difusse slot..
Then go to your glossy set that to around 0.7 .. and subdivs to around 10.
if you have the latest version of vray you can use Highlights also.
Not forgetting to set your reflection to around 30 = grey...
you could also use Frensel aswell .... play with it and see what you get..

and thats really it... Cheers...

Vray Opacity map

Leaves, feathers, and many other things like those would be a pain to model. So the use of opacity masks have been used on grids to give a quick version of these things.

Its the same principle in VRay material but it would be setup slightly different seeing as how there is no opacity slot. For this we use the refract slot and set the IOR to 1. That takes care of your opacity.

A common mistake in the standard material with this method is people forget that if they want to have specular highlights they will need to use a mask in the specular slot to kill the highlight on the supposedly empty transparent areas. With VRay material reflections are used for specular highlights so we will need to add the mask to the reflection slot instead.