Help Needed With Anisotropic Material

[Wilyman]

Hi,

I'm trying to recreate the following material for a model I'm making...


(The repeating metal circles around the cd player)

I've made some maps in Photoshop that seem to give the right shape when used as bump or displacement maps. However, I want to get a small anisotropic highlight on each circular segment, and I only seem to get large highlights down the entire object. See below.

Is it possible to achieve this effect without actually creating geometry for each segment. I need each one to behave like the top of the cylinder in the image below.

Any help would be much appreciated.

Cheers,

John

[vance3d]

can you post the map you are currently using? I think it is possible but the map has to be correct.

V Miller

[Wilyman]

Sure. The one used in the picture above is...



But I've also tried...



Cheers,

John

[percydaman]

i dont think your bump is correct. You want a overall flat surface, just with the radial like scratch type bump.

[Wilyman]

I've tried that too...



But the result was the same - One big highlight down the object.

[vlado]

You might need a smaller light source and stronger bump values.

Best regards,
Vlado

[Wilyman]

Thanks for the tips Vlado.

I've spent a long time experimenting with the size and position of my light sources, and with the values of bump and/or displacement maps, but I can't seem to come up with anything resembling an anisotropic highlight.

The scene and materials are definitely set up to give anisotropic highlights as the pics below show, but how can I get the displaced surface to behave in the same way as the array of cylinders?

Cheers,

John

[percydaman]

http://www.vray-materials.de/all_materials.php?mat=383

check that out.

[Wilyman]

Thanks for that. I check that site every day, and still somehow managed to miss it.

Unfortunately it's not giving the result I need though. It's just altering the reflection glossiness so that the highlights are sharper at the top of each circle. The highlights aren't going to rotate around the centre of each circle as the camera or light moves, as they would in real life.

Thanks for everyone's help so far. Any more suggestions would be very much appreciated.

Cheers,

John

[andrewjohn81]

Well, I'm not sure if it would work, but that material gave me an idea.

If you create a cylindar, non max, with a top cap and put a planar map on it you Don't get the result you are looking for. If you take the point in the middle and just raise it up a hair you Do get the result you are looking for. Do you follow where I'm going with this yet?

If you take your current map and, at the center of the circle, add a slight gradient where the lightest part is in the middle of the circle it should bend the normals slightly out from the center. This basically should create an ever so slight cone shape for each part.

I don't have cpu time right now to test that out, but I thought I'd share the idea anyway. Hopefully you followed my confusing description of the idea.
Post results if it works at all. I'm interested to know myself.

I would put it on top of your current map, the second one that didn't end up looking more like fish scales, so you also get the correct bending of the light at the surface for the blurred reflections also. That slight bump should be important for that as well. Just ignore that if it's confusing.

[studioDIM]

This is without lights (only the HDR bg and GI), done with good old 1.09.
Simple bump, and high enough QMC AA sampling/sensitivity

Not perfect, but should give an idea

Lele