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Surface Curvature-based Textures

Posted: Sun Sep 15, 2013 11:34 pm
by jfrancis
This is nothing too spectacular, but I thought it was interesting enough to mention.

I was playing around with an obscure filter, Alien Skin Eye Candy 'Swirl,' which produces lines either across or along gray-scale gradients - more about that in this video I made - when I thought it might be fun to try and use it to process some surface-dependent masks from ZBrush...

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Funky surface masked in ZBrush by smoothness.

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Unwrapped into a UV map

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Processed twice with Alien Skin Eye Candy Swirl, once at 0 degrees and once 90 degrees to the gray-scale gradient, and the two separate textures combined into a grid that notices object smoothness.

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Re-masked against the smoothness mask to limit the warped grid effect to just the less flat areas.

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Here comes the Maxwell part :) --

I used the texture to make some sort of alien crack pattern that somewhat understands the curvature of the underlying surface.

Re: Surface Curvature-based Textures

Posted: Sun Sep 15, 2013 11:41 pm
by jfrancis
Here's a second thing I did using the same Aline Skin Eye Candy Swirl filter:

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Alien Skin 'Dots' texture - which is really a bunch of overlapping circular gradients combined using a 'lighter color' blend mode. It's the basis for Voronoi cell patterns, etc.

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Applied the Alien Skin Eye Candy Swirl at 80%, which is along a vector neither fully along nor fully across the grayscale gradient.

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I quite liked the look so I gradient color-mapped it in Photoshop for fun.

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Here's the Maxwell part - I used it as a material mask between diffuse red and 60% gold metal. It tiles, and I thought it was quite decorative.

Re: Surface Curvature-based Textures

Posted: Mon Sep 16, 2013 12:36 am
by Maximus3D
Nice and interesting results, it looks a bit like a cavityshader or inverted such as you can find in Zbrush. This could be used for many exciting things.
Keep the examples coming. :)

/ Magnus

Re: Surface Curvature-based Textures

Posted: Mon Sep 16, 2013 1:16 am
by jfrancis
A ZBrush mask was part of the process in the first example. I just wanted to see the stripes from the Swirl filter to acknowledge the gradient directions in the ZBrush mask.

Re: Surface Curvature-based Textures

Posted: Mon Sep 16, 2013 3:16 pm
by eric nixon
Nice logic/ideas... thanks, can z-brush generate this curvature map for any model (something imported)?.. hmm why not. I would like an automatic workflow to generate 'worn area' weightmaps for scratches etc.

Re: Surface Curvature-based Textures

Posted: Mon Sep 16, 2013 10:04 pm
by jfrancis
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Various mask options out of ZBrush. All require parameter tuning, and none does exactly what I would have expected.

They get cteated as polypaint masks (resolution depends on polygon density) and then are written out via UV unwrapping into UV maps.

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ZBrush does a pretty nice job of UV unwrapping.

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Alien Skin Eye Candy Swirl at 0 and 100 percent (along and across gradient) the two combined with darken blend mode.

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I was hoping for some sort of automatic tree bark that respects object topology.

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Eye Candy cracks combined with Smoothness map and darkest ares lifted to 50% gray.

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I was hoping for some sort of edge-based deterioration like on a rubber tire, or weathered, water soaked or burnt log, or something.

Re: Surface Curvature-based Textures

Posted: Mon Sep 16, 2013 11:31 pm
by jfrancis
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I ran the Fractalius plugin on the already masked Alien Skin displacement from above. Fractalius doesn't do much on the low frequency masks, but it likes the high frequency images I used above.

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It looks surprisingly like tied or glued, wrapped tissue paper.

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Here it is with greater displacement specified in the shader.

Re: Surface Curvature-based Textures

Posted: Tue Sep 17, 2013 12:01 am
by Mihai
That looks great! I can see many uses for that....

Tutorial please! :mrgreen: We will put it on our web, make you famous.....

Re: Surface Curvature-based Textures

Posted: Tue Sep 17, 2013 1:43 am
by jfrancis
Mihai wrote:That looks great! I can see many uses for that....

Tutorial please! :mrgreen: We will put it on our web, make you famous.....

Will do :)

Re: Surface Curvature-based Textures

Posted: Tue Sep 17, 2013 6:24 am
by eric nixon
That wrapped tissue is awesome :mrgreen:,

now where is the perfect filter/workflow which makes anisotropy anglemaps :roll: < always have to fudge these

Re: Surface Curvature-based Textures

Posted: Tue Sep 17, 2013 11:16 am
by Polyxo
These are nice looking effects, especially the glued paper!
The way Zbrush unrolls geometry is very suitable for this kind of work as it somehow manages
to flatten most complex stuff as just a single island if one doesn't tell it to use polygroups.
What's cool too is that one can tweak the mask and can see the effect update.

Re: Surface Curvature-based Textures

Posted: Wed Sep 18, 2013 8:40 am
by jfrancis
Next is no new information, it's just me playing around with Fractalius as the displacement map generator. The object material is wizard SSS orange juice combined with a simple diffuse layer.

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Might make a cantaloupe skin if tuned?

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Reminds me of the bottom of a watermelon that's been sliced many times.

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Some sort of leathery elephant skin?

Re: Surface Curvature-based Textures

Posted: Wed Sep 18, 2013 10:29 am
by Fernando Tella
Very nice experiments!

Re: Surface Curvature-based Textures

Posted: Sat Sep 21, 2013 9:28 am
by rusteberg
jfrancis wrote: Image
Here comes the Maxwell part :) --

I used the texture to make some sort of alien crack pattern that somewhat understands the curvature of the underlying surface.
looks like a poorly folded piping hot burrito..... in a good and delicious way..... i'd let that one sit on the counter for a while before taking a chomp at it! :D

Re: Surface Curvature-based Textures

Posted: Sat Sep 21, 2013 9:33 am
by rusteberg
jfrancis wrote:Image
what's happening here @ the left corner piece where it seems noise is converging?