[Mihai]

Someone asked for this, so here are a couple of examples. First one doesn't actually have any scratches, lets say they are so small they aren't visible at this distance:




This material took exactly 5 seconds to create. I just loaded up the ior file for aluminium and gave it a roughness of 35.

Second example with scratches, I just added a scratchmap to the bump. That's all there is to it.....


(note: there's no scratchmap on the tube thing, didn't uv map it)

Of course you can mix other metals with this bsdf, for example if you think it looks too shiny, just add a default bsdf and darken it's reflection value....lots of posibilites but to get a nice looking material doesn't take long at all.

[Maya69]

thank mihai for stuff

[Sheik]

So, how about anisotropy? You can create the same lighting effect as with the scratch map, but without the actual scratches, right? Is anisotropy supposed to work on a flat surface also?
Sheik

[Mihai]

Anisotropy really means directional reflections. I added the scratchmap not to create anisotropy in this case, but to have visible scratches. Anisotropy works on flat surfaces too.

[adamwade]

Mihai,

I was doing some brushed AL the same way and came accross something strange. When I checked the Normal Mapping box next to the bump the metal goes way black. When Normal MApping is off then its fine. What is going on?

I though Normal mapping would simply keep the scratch map properly oriented over the object, but maybe it's something completely different.

[w i l l]

I know this is about textures but... nice image, I like the contrast between the black and silver. Dark.

[Mihai]

Adam, maybe it's something with the normalmap....in any case for such small bumps I don't think you would see a difference between a normal or bumpmap. Just use a bumpmap.

[Eric Lagman]

Thanks Miha you da man. I was actually doing some tests of my own on some flat surfaces to see what I can get by using scratchmap in the anisotropy channel. I am working on a project now that will require just bent sheetstock brushed aluminum. I sure most arc viz people will want to see the flat surfaces also, since this is most likely what they will be using. I have found some interesting results, and will share them along with the scene file later today. Thanks again for helping us out.

[Maximus3D]

Pretty good example Mihai interesting to see, thanks

Adam: Normalmapping will probably just turn your object(s) black as you said it did when you don't assign a real normalmap to the model, it can't just be used like that as you tried. You can Google if you wanna know a bit more what exactly normalmaps is what how they work and what they do. So yes it's something completly different.

/ Max

[Mihai]

Eric, don't use a scratchmap in the anisotropy angle channel, or the anisotropy strength channel, you're supposed to use a gradient for those channels. Search for angle map, there is an example. Anisotropy is cool but it doesn't mean now we have to make all metallic surfaces with anisotropy.

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[Mihai]

Yes that's exactly right. With a very fine highrez bumpmap you would have anisotropic reflections if the scratches all go in one direction.

[Eric Lagman]

Eric, don't use a scratchmap in the anisotropy angle channel, or the anisotropy strength channel, you're supposed to use a gradient for those channels. Search for angle map, there is an example. Anisotropy is cool but it doesn't mean now we have to make all metallic surfaces with anisotropy.

To late already put a scratchmap in the anisotropy strength channel. No turning back now. As far as doing it because it is cool that is not why I am doing this. I am doing this for a paying project, and to try and help eduacte myself and others. Please don't belittle my efforts with comments like this. If the manual was clear on this or there were some samples sent with 1.0 there would be no need for all this experimintation on things that seem very straightforward based off of your explanation.

I dont really see the logic in putting a scratchmap in the bump channel to achieve an anisotropic effect for flat surfaces, then putting a gradient map in the strength and angle channels for other surfaces. I saw olivers tests on the round cylinder using a gradient weeks ago. Could that have just been done with a scratch bump map. If so Why would I ever use the anisotropic effect at all if I can do it with a map in the bump channel. Also your definition of anisotopic meaning directional reflections is correct. The direction is determined by the direction of the scratches on the surface. So again why not just put a bump map or use simple roughness when you want an anisotropic effect. Should I think of the anisotropic angle and strength as just a modified version of the roughness channel that allows me to control direction? I may have just answered my own questions by typing this. I will experiment some more.

[Mihai]

I'm not trying to belittle your efforts I was just saying how it was ment to work.....the point of having an angle map as a gradient is for occasions when the scratches are really too small to be visible, like they would be if you were using a bumpmap.

[Eric Lagman]

Here are the materials I got by putting the scratchmap in the anisotropic channel, and leaving the roughness to 0 on one bsdf layer. The strength does nothing to effect the result, only the scratchmap itself. Lighter = more scratches and blurry reflections, and darker = less scratches and less blurry reflections. I suppose If I just put this map in the bump channel I would get the same result? Below is the zip file with the maps and scene if anyone wants to have a go at it and share. I have to say I like the result even If I went about it the wrong way. If it looks good it is good right




http://www.ericlagman.com/Aluminum_Test.zip