How might I go about achieving these refractive materials

[rjohnson33]

Hi, I was hoping someone could give me some advice on how best to achieve the plastic elements in front of the flash
seen on the front of this camera and also at the back (the plastic in front of the flash indicator)
As you can see they have a ridged or patterned look to them but they're flat on the surface.

Part of the problem is I'm not sure technically why they look like this.
If I were taking this to the nth degree and were to model those shapes somehow I'm not sure how they would be
formed in the plastic elements themselves.

If I were being sensible and used a mapped material what slot would it go in to get this look?
I was thinking maybe Refractive Glossiness, Refraction Value itself or even IOR?
Or maybe it needs an SSS material with a map somehow incorporated?

Thanks for any suggestions

[simmsimaging]

Looks like a weird lens filter (Cokin style) in a holder in front of the lens. Easy to make anyway: outer part is just clear and there are a couple of ways to do the orange swirl. One would be to make a map with the pattern in orange on a white background and use that to map your refraction colour (I wouldn't bother with SSS myself) and use a black and white version of the same to map the refraction glossiness (use the Output curve to adjust the amount of glossiness). Another would be to make a clear material and an orange refractive materials and put them in a VrayBlendMaterial with the black and white version of the pattern as a blend mask. The latter might be better if you want to play with the refractive Fog a bit more freely.

[tricky]

Looks like a weird lens filter (Cokin style) in a holder in front of the lens. Easy to make anyway: outer part is just clear and there are a couple of ways to do the orange swirl. One would be to make a map with the pattern in orange on a white background and use that to map your refraction colour (I wouldn't bother with SSS myself) and use a black and white version of the same to map the refraction glossiness (use the Output curve to adjust the amount of glossiness). Another would be to make a clear material and an orange refractive materials and put them in a VrayBlendMaterial with the black and white version of the pattern as a blend mask. The latter might be better if you want to play with the refractive Fog a bit more freely.

I think he's on about the flash diffuser.

Map a texture like this perhaps:-
http://blog.nikonians.org/martin_joe...-schematic.jpg

[rjohnson33]

I was talking about the flash diffuser, yes. The uppermost one in the centre. Sorry I should've been more descriptive.

Thanks for the link to the texture. I'll give something like that a go in the various refraction material slots and see what works best.
I wonder technically why it looks like this though. Is it ridged on the internal side maybe or something inherent in the material itself?
Will have to do some research.

Simmsimaging, thank's for your advice on the filter. It'll come in handy with that element.

[simmsimaging]

Should have read more carefully

Tricky's map should get you pretty close (might need to use more of a cylindrical depth map rather than flat ridges). Just apply it to the bump map on the diffuser, but only on the back/inside face, and you should hit it.

[danieljhatton]

Its concaved on the inside, different severaties on each horizontal strips and flat on the front facing us. It might be best to model it, for best results, using poly modelling with a turbosmooth, and then applying the appropriate glass with refraction. That's what I would do anyway, especially if you are going for gold. It's the most effective way when modelling car lights and lenses.

[rjohnson33]

Daniel, would you be able to tell me what you mean when you say different severaties on the horizontal strips?

Are you suggesting to model the concave inner face and flat outer and then use a map in say the refraction slot for the differing severaties
or is there some sort of shaped profile formed by these strips that I could model in also to cause the effect entirely with geometry?