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Fabric (crushed)

Posted: Thu Oct 23, 2008 10:33 am
by bjorn.syse
Hi!

I could need some input in going about creating a material such as this:

ImageImage

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It's called "Crushed" and seems to have a bit of that custom falloff effect. Here's the displacement/bump map I've made from a scan of the fabric:

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Initial thoughts are to use a displacement map in combination with the .r2 from eg. the towels in the material library. Seems this might be a way to go, however - I wonder if there's a good way to do this without the displacement since it increases the render time so much.

Image

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ImageImage

Would normal maps be feasible, do a better effect than bump?

Thankful for any input

- Björn

Posted: Thu Oct 23, 2008 2:25 pm
by Bubbaloo
I think it depends on how close it will be in the render. If it's seen up close, you should use displacement. Further away you might be able to get away with normal/bump.
Your material looks pretty close.

Posted: Thu Oct 23, 2008 2:42 pm
by bjorn.syse
Precisely. Perhaps I can have two similar materials, one with displacement and one without.

Are normal maps better than bump? How can I convert a bump to a normal map?

Posted: Thu Oct 23, 2008 2:49 pm
by Mihai
There is Crazybump, and also a PS plugin from Nvidia that let you convert it to a normal map.

Posted: Thu Oct 23, 2008 3:01 pm
by kami
I always had the impression, that a normal map works better ... the problem is, that you cannot control the height of your bump by numbers, but have to change the texture.

Posted: Thu Oct 23, 2008 3:59 pm
by bjorn.syse
Oh, that might be unpractical.. but once i get it right i guess it's fine.

I don't think the manual explains this, but: Can I set negative bump values, and what effect does it have?

- björn

Posted: Thu Oct 23, 2008 4:01 pm
by Bubbaloo
Instead, you can just invert the texture in the material editor.

Posted: Thu Oct 23, 2008 5:37 pm
by bjorn.syse
I see bubbaloo,

Mihai,kami: Tried NVidias plugin, thank you.

I can't seem to squash any more bump out of this than this using regular bump mode:

Image

I'm using 80 as bump value. Should this really be the case? it seems it doesn't show at all... Perhaps I'm doing something wrong.

zip with mxm and textures: http://dl.getdropbox.com/u/114792/crushed.zip

- Björn

Posted: Thu Oct 23, 2008 7:07 pm
by yanada
:D

Posted: Thu Oct 23, 2008 8:30 pm
by bjorn.syse
Thank you yanada! That was a great program. I'll post some results soon..

Posted: Thu Oct 23, 2008 10:16 pm
by bjorn.syse
Not there yet, but this is what it looks like when using color maps aswell:

Image

.. hmm.

Posted: Thu Oct 23, 2008 10:19 pm
by Bubbaloo
Do you still have the nd at 20? That's too high. That's a metal-like quality I think. Lower it way down and try raising the roughness to 98-99.

Posted: Thu Oct 23, 2008 10:29 pm
by bjorn.syse
In this image the Nd is at 5. I Also put roughness at 98, (though it was at 95 in the previous picture.

Image

I guess the scanned image I have is kinda blotchy... you know any neat way to even out the colors in photoshop without blurring the details of the texture?

regards,

- Björn

Posted: Thu Oct 23, 2008 10:38 pm
by Bubbaloo
Try nd = 1 - 1.5

And as for the diffuse map, I think it looked better without it. Looked closer to your ref pic before.

Posted: Thu Oct 23, 2008 11:08 pm
by bjorn.syse
Really don't know what I'm doing wrong, but as soon as I turn down Nd to 1.3 or something, the material goes dark as coffee.

Try this with the included towels for example, just change their nd to 1.3 and watch the light dissappear...