Author Topic: Cloth/Fabric Shader  (Read 5522 times)

2017-05-31, 20:20:53

viscorbel

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Cloth/Fabric materials are imho most problematic of all, and often are the weakest point in many renders.
The regular ggx/blinn/whatever brdf is not really suitable, it always comes down to some fallof cheat or weird-ass anisotropy to sort-of make it look correct'ish, but comparing to actual scanned materials the result is not at all realistic

I saw this BTF + BRDF approach mentioned on Vray forums and thought to mention it here as well, as Corona seems open to ideas.
Here's an oldish paper http://www.graphics.cornell.edu/pubs/2006/IM06.pdf
and there is also a cloth shader plugin for vray/maya called  https://github.com/vidarn/ThunderLoom
Anyway, I'm not a tech guy and have no idea if there's anything of worth in the links, but damn, I wish for a nice cloth material all the time. I know you guys make things happen :)

Is there any interest in this direction at all? I think a cloth shader would be amazing help for interiors which seem to be bread and butter for most Corona users.

2017-05-31, 21:35:04
Reply #1

apjasko

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Andrew Price touches on why fabric materials often don't look right. I believe if you know how to use Substance, you can create your own fabric materials that touch on issues in the paper you provided. I don't feel it's necessary to create a dedicated shader/material for fabrics. You just have to understand how to create the desired textures.

2017-05-31, 21:56:36
Reply #2

viscorbel

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Interesting, looks like the substance approach might work, even though it's not an easy one.
I think that the most important piece here is a high resolution normal map that accurately replicates the woven structure combined with appropriate reflectivity and glossiness.
On the other hand it looks like a hours and hours of work for each new fabric sample client throws at you and purchasing yet another piece of software. It would still be very much a 'specialist' approach instead of something easy to use for the average artist.

2017-06-01, 15:02:12
Reply #3

apjasko

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That's very true, not so much for the average artist. After I saw this video, I realized how complex fabric shading really is. But a skill set such as Substance is a good example of what sets artists apart. I'm curious what the dev team has to say about a feature like this.

2017-06-01, 15:49:20
Reply #4

pokoy

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I guess an Oren Nayar would already help a lot and there are probably other shading models that are more suited for fabrics. +1 here!

2017-06-02, 21:13:06
Reply #5

Njen

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Substance is easy to learn and with a personal license costing $20 a month (using the 'rent to own' system), and combined with the fact that a few weeks ago Substance Source got 150 new fabrics that you can download (subscribers can download 30 materials per month for free),  makes it totally worth the investment.

2017-06-03, 17:23:59
Reply #6

Alexp

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Would be nice to implement a Corona/Substance material like you can do in UE4.