Poll

What option do you prefer to control hair highlights size?

Glossiness (currently used, also behaves similarly to CoronaMtl)
Roughness (usually hair shaders/materials use roughness instead of glossiness)

Author Topic: 1.7 - Hair shader playground and feedback  (Read 18225 times)

2017-07-05, 12:00:36

maru

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Let's share our tests and for fun renders with the new hair shader here!
You can get the newest daily build with hair support here: https://coronarenderer.freshdesk.com/support/solutions/articles/5000570015-daily-builds

Just a few very simple tests for the beginning:

Default settings:


Melanin = 0,25


Melanin = 0,25; pheomelanin = 1


Diffuse color altered:


Glints = 1


Glints = 0


Glossiness = 0,8


Glossiness = 0,2


Glossiness = 0,2; softness = 0,2


Glossiness = 0,2; softness = 0,5


Highlight shift = 0


Highlight shift = 2,5


Highlight shift = 5



Bonus!





2017-07-05, 12:21:38
Reply #1

maru

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2017-07-05, 19:10:36
Reply #2

zuliban

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looks like a fun material to play with, is highlight shift the same as anisotropy reflections?

2017-07-05, 20:09:43
Reply #3

JoeVallard

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Downloaded the hair farm demo and one of the example scenes. I did this back on the Jun 21st build and i'm not sure if anything has changed since then but i did have some strange issues with the GI precomp hanging when rendering the Hair material (both render and interactive render). Anyways the setting are slightly tweaked from the default shader.

@Maru ty for posting this its nice to see these kind of images to quickly show what each setting does.

2017-07-05, 22:50:47
Reply #4

cecofuli

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What about H&F shading? How can be possible to add material to 3ds max H&F?

2017-07-05, 23:03:34
Reply #5

ylucic

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not at all a technical test...but had fun doing it..
works well with a couples of lights..
the ones with black background only have and light in the zenith...and did a quick reference image with just a corona material with similar color to see what the shader did...

it would be nice to have support for native hair and fur for the this shader...to do other stuff besides hair

cheers!
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SCL

2017-07-06, 16:51:53
Reply #6

Fritzlachatte

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Hi, all those images look interesting, but I don´t realy understand (in case of fur not hair) the advantage over a selfmade shader.
For rendering a pleasant fur plaid, it was more the absence of 100% utilizing AD Hair&Fur and having massive RAM flooding. The optic for itself was good enough, it was more the rude hair/fur structure, not the shader which bothered me and spit out low memory warnings like hell.
The only alternative seem to be Ornatrix or HairFarm, but I always had the wish corona would offer an inhouse solution like corona scatter instead of Forestpack.
What is the real benefit of the shader? Is it just for Hair in combination with e.g. DAZ 3D ?! If there would be an implementation of H&F like Vray etc. use, would H&F still remain as a RAM eater? 
Does Ornatrix handle this problem better? Lots of questions sorry.

2017-07-06, 16:57:22
Reply #7

maru

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Apart from the hair shader, which is physically plausible (it actually simulates how light reacts with real hair), Corona can now take advantage of instancing when rendering hair. So you can expect huge RAM saving when rendering hair now*. Keep in mind that all this hair related stuff is still WIP.

*devs, please correct me if I'm wrong

2017-07-06, 17:52:08
Reply #8

TomG

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As someone who does not know any of the details of the calculations involved (not being a coder!), there are two differences that are still visible to me about the hair material just from rendering it. The first is that it has transmission through the volume, somewhat like SSS, as can be seen in the image below with an array of regular cylinders lit by a sun.

The second is that the shape of the highlight is different, somewhat like anisotropy, as seen in the other image where the hair material is applied to a regular sphere.

And I am sure there is much more to it than that! But those are two visible differences that I hope show some ways that the hair material is different from any other sort of regular material (plus it has controls for melanin and pheomelanin to control color, has colorless and colored speculars, etc. - all of which makes it more suited to the task of rendering realistic hair and fur than regular materials).


2017-07-06, 18:18:11
Reply #9

TomG

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Nothing dramatic here, just wanted to have a scene with dynamics, so used the free sample scene from Ornatrix (https://ephere.com/plugins/autodesk/max/ornatrix/docs/5/Simple_Bird_With_Dynamic_Feathers.html)  and went for a shiny metallic look for the bird using CoronaHair.

Aha found my test youtube, so uploaded it there:

« Last Edit: 2017-07-06, 18:24:27 by TomG »

2017-07-06, 19:30:25
Reply #10

Juraj Talcik

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Hi, all those images look interesting, but I don´t realy understand (in case of fur not hair) the advantage over a selfmade shader.

You definitely can't make certain materials using generic shader look convincing. Hair, Skin, Wood and certain rough materials have such different surface characteristic (multi-lobe specular response, special subsurface behavior, multi-directional anisotropy,etc..) that making them from generic shader will look wrong no matter how much effort is given to it.

That, and very nice default presets optimized for characteristic look.

All these weird, low-poly hair models make the shader look like from 1995 though :- ). Games running on PS4 (Rise of tomb raider, Uncharted 4, Horizon Zero Dawn) have higher fidelity in hair than this.
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2017-07-06, 20:01:55
Reply #11

TomG

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All these weird, low-poly hair models make the shader look like from 1995 though :- ). Games running on PS4 (Rise of tomb raider, Uncharted 4, Horizon Zero Dawn) have higher fidelity in hair than this.

Yes, sadly I am brand new to Ornatrix, and have to rely on their free scenes for testing, just to see if things work :) Hopefully a hair artist will get into doing some testing and start showing how it all looks on some beautifully modeled hair! If anyone knows of any super-good models / scenes that come with good Ornatrix set ups, that would be awesome! I stopped my search for now with Ornatrix's own setups, just to get started :)

2017-07-07, 08:34:33
Reply #12

Fritzlachatte

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Thanks for all these demonstrative explenations.
I really have to play around with it to test the RAM saving aspect. But Juraj`s rude 90s comparison was my first impression as well, a little bit if Malibu Stacy refuses washing her hair.
But this shows clearly the need of addons like Ornatrix or a proper use of H&F ... or somewhere in the future "Corona Hairbrush 3000 "

Anyway thanks for explaining.
 

2017-07-07, 10:44:27
Reply #13

maru

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Better test object.
Checking the "render as planes" option, which is hidden in devel/debug rollout.
When enabled, rendering is much faster and with less noise, but the hair appear less realistic. Currently there also is an issue with Embree which may introduce some artifacts when this option is enabled.
Rendering for 2 minutes.

2017-07-07, 12:13:56
Reply #14

Juraj Talcik

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I would say that's super trade-off. I would rather render billion planes, I cannot tell the difference :- ). The AA is superior too.
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