Coating material tests

General questions about Indigo, the scene format, rendering etc...
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CTZn
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Re: Coating material tests

Post by CTZn » Wed Dec 05, 2012 2:00 pm

I did it myself ! Meh it's melting...

You can set the time it took for the coating to dry out in the shader for the Thickness parameter.

Or perhaps was it too much solvant...
Attachments
coating_with_absorption_and_procedural_drying.jpg
Thickness: 0.0 <- 0.75 -> 2.5 mm
Drying Speed: 0.0 <- 0.52 -> 1.0
Melted_Coating.igm
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CTZn
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Re: Coating material tests

Post by CTZn » Wed Dec 05, 2012 3:18 pm

Uploaded Liquid_Coating.

Image
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StompinTom
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Re: Coating material tests

Post by StompinTom » Thu Dec 06, 2012 1:43 am

CTZn wrote:Uploaded Liquid_Coating.

Image
Beautiful!

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Re: Coating material tests

Post by StompinTom » Thu Dec 06, 2012 4:58 am

1. Bump on the underlying material doesn't seem to show up... Trying to make a varnished wood or similar, so you get a bit of grain detail underneath a smooth glossy surface.

2. Coatings + double-sided materials + mix materials are just asking for node support (Indigo node types) in the Blender exporter!!!

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CTZn
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Re: Coating material tests

Post by CTZn » Thu Dec 06, 2012 5:11 am

Thanks Tom !

The next one can get real creepy sometimes... noise fun.
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Jammy_Coating.jpg
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OnoSendai
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Re: Coating material tests

Post by OnoSendai » Thu Dec 06, 2012 5:43 am

That's.. a bit gross :)

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CTZn
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Re: Coating material tests

Post by CTZn » Thu Dec 06, 2012 6:08 am

I was frankly hesitant in uploading it... but it's just the previous material with a noise. Aw don't be scared that's strawberry :D

It's not optimum yet, I may even update the clean version. Anyone is welcome in polishing my empirical experiments.
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Pibuz
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Re: Coating material tests

Post by Pibuz » Thu Dec 06, 2012 9:39 pm

Those tests are really cool guys!

I'm very interested in the liquid coating material: con you CTZn explain a little how it works?

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ENSLAVER
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Re: Coating material tests

Post by ENSLAVER » Thu Dec 06, 2012 10:54 pm

I love the red one :D

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Re: Coating material tests

Post by FakeShamus » Fri Dec 07, 2012 1:56 am

StompinTom wrote:1. Bump on the underlying material doesn't seem to show up... Trying to make a varnished wood or similar, so you get a bit of grain detail underneath a smooth glossy surface.
I've been trying to do something similar and noticed that too, bump parameter has no effect on the substrate material.
but I'm picturing it looking so cool! The coating material (like a varnish or stain) looking thicker in the recessed areas of the wood grain, for example.

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OnoSendai
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Re: Coating material tests

Post by OnoSendai » Fri Dec 07, 2012 2:10 am

Yes, bump on substrate material is not currently supported. Guess I'll try adding that in.

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galinette
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Re: Coating material tests

Post by galinette » Fri Dec 07, 2012 2:23 am

CTZn wrote:Thanks Tom !

The next one can get real creepy sometimes... noise fun.
Some physicist comment:
It's too visible that you only use the normal for computing the thickness. This leads to some undesirable effects:
- The sharp angles show a sharp change in thickness
- The top flat part of the base has virtually nothing on it, while it should be one of the thickest (it's at the bottom, plus it's lying flat so the liquid should not flow from it

Some more advanced shader could make use of the altitude as well as the normal. Even better, having access to the surface curvature in ISL. Ono, that's something I use in my experimental stuff and I dream of it for a while in renderers. It allows awesome effects such as correct thickness calculation of a non-spheric soap bubble, paint drying and everything that relates to surface tension since this is the main parameter of it...

Sorry for criticizing, that's looking very good (and scary :? )

Cheers,

Etienne
Eclat-Digital Research
http://www.eclat-digital.com

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CTZn
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Re: Coating material tests

Post by CTZn » Fri Dec 07, 2012 2:27 am

Pibuz wrote:Those tests are really cool guys!

I'm very interested in the liquid coating material: con you CTZn explain a little how it works?
Hi Pibuz, it's pretty simple:

The slope is driving the thickness. A curve is applied to the slope, proportionally with the drying time/solvant quantity choosed and that's what is distributing the overall thickness. The noise also has a vertical scale modified by the slope.

Glad you like it guys. I'd never go by myself to a theater watch a scary movie I swear !

@Etienne: THANKS for criticism actually. You accidentally discovered that I'm happy to learn, so thanks a lot for the heads up. I'll get back to you with that.
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OnoSendai
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Re: Coating material tests

Post by OnoSendai » Fri Dec 07, 2012 2:53 am

galinette wrote: Some more advanced shader could make use of the altitude as well as the normal. Even better, having access to the surface curvature in ISL. Ono, that's something I use in my experimental stuff and I dream of it for a while in renderers. It allows awesome effects such as correct thickness calculation of a non-spheric soap bubble, paint drying and everything that relates to surface tension since this is the main parameter of it...
Interesting idea. Could also be used for dirt shaders. What kind of curvature definition would you suggest?

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galinette
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Re: Coating material tests

Post by galinette » Fri Dec 07, 2012 4:16 am

OnoSendai wrote:
galinette wrote: Some more advanced shader could make use of the altitude as well as the normal. Even better, having access to the surface curvature in ISL. Ono, that's something I use in my experimental stuff and I dream of it for a while in renderers. It allows awesome effects such as correct thickness calculation of a non-spheric soap bubble, paint drying and everything that relates to surface tension since this is the main parameter of it...
Interesting idea. Could also be used for dirt shaders. What kind of curvature definition would you suggest?
If you just need the mean curvature radius, you may compute the curvature radii along two arbitrary orthogonal axis (for instance, orthogonal tangent space), the mean radius being Rm =1/(1/Rx+1/Ry). More conveniently, if you define the curvature C=1/R, this gives : Cm = Cx+Cy. Advantages of Cm and Rm, they are independent of the basis, you can compute them in any hidden tangent-space basis, or more cleanly find a formula not requiring an explicit tangent space. Note that this is signed, you must orient the curvature with a convention (for instance, oriented surface normal). This gives a zero curvature for a horseshoe shape.

More generally, you could define curvatures from any 2 or more degree term of the surface differential.

One difficult issue would be that standard linear normal shading gives constant curvature over the triangle, and thus curvature discontinuities.
Eclat-Digital Research
http://www.eclat-digital.com

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