Trying to make a VRAY material behave in vray light the way it does in reality...

[Kinetic99]

Hello and thanks for your time,

I have two vray MTLs on an object:
1) high polished metal
2) a frosted metal

The frosted material has the exact same settings as the high polished material except that it has Ward on and a noise bump map on with a 0.002 size-turbulent with explicit mapping on.
In reality, this frosted material is a sandblasted metal, so that if you look at it close-up, it has a random, grainy, bumpiness to it. The noise bump map is perfect for emulating this look.

In the render, the high polished metal material is typical dark and shiny with sharp contrasts-like silver, and the frosted metal material is much lighter in colour and diffuse. This is exactly how it looks in reality.

But if the object is rotated so that the object reflects the highlights and the object has strong high white reflections, the frosted metal material is completey washed out with no bumpines and all you see in the render is a white object.

In reality, what I should be seeing is as the high polished metal material reflects the light and becomes white with highlights, the frosted metal material becomes relatively darker! So that the frosted metal material never dissapears in the strong white reflections and stands out against the completely white highly reflective silver material.

I want to emulate this quality so that the frosting is light in colour in normal lighting, and darker in colour in high-white specular reflections. Always remaining diffuse, bumpy, with no obvious reflections.

I have already messed around with H and G glossiness, reflection, diffuse, etc maps, glossiness levels, but no luck

Is there away to achieve this quality??

[grantwarwick]

I honestly have no clue what you are on about haha but when it comes to micrnoise, Bump mapping doesn't cut it. You need Vray displacement.

Please post a screenshot of reality vs render and I will make the material for you.

HMmmm, now that I think about it, I think I know what you are getting at.
Unfortunately, I feel Vrays bump mapping is terrible these days.

Octane can produce full anisotropic highlights using extremely dense bump mapping only, no glossiness maps etc (Like reality)
When I have tried to emulate this with vray it falls flat so I resort to displacement.

[Kinetic99]

great start and thanks for your courage in answering this question.
As long as Vray displacement maps (using noise for relief) doesn't add to my render times then its worth a shot. I thought about this too but since frosted bumpiness is so small - almost microscopic, I thought bump maps would work. I'll also keep on trying..

An easy way to think of this frosting effect is like this: when there is no sharp highlights reflected of the dark metal object, the frosting material is relatively light in colour- (like typical frosting), but when the object is moved in the light so that the light source is refleting off the metal object and all you see is white specular, then this frosting material is relatively darker ( it doesn not have the same relfectivity, glossiness as the metal so it must react with the light in different way).

what do think?

[Deflaminis]

Might be worth trying to turn off filtering for the bump so you can get those sharp points instead of a blurred average. (Or use vrayhdri map for the bump.) I sometimes forget to do this and it does make a difference from time to time.