87 replies to this topic

[ssh]

Hello,

Just would like to share hair shader I've done.
This shader implements well known Marschner model proposed here:
http://www.graphics....r-sg03final.pdf

Video on Vimeo:

View on Vimeo.

Youtube:
http://www.youtube.com/watch?v=IYMF2a_ts2U

Tested both in H10 and H11.





Shader Parameters:
Diffuse color and intensity.
please note that for dark hair diffuse intensity is usually very small

Overall specular intensity and color. Computed speculars are multiplied with this values.
This parameters are not physically correct and are provided for convinience only.

Different light masks and categories lets specify which lights are contributing to diffuse and specular computation.

Specular components:
Primary Highlight (R ): Strong primary specular peak.
Secondary Highlight (TRT): Colored secondary peak.
Backlight (TT): Colored component that appears in back lighting situations. That is the bright halo around the hair.

Each component has it's own intensity and color multipliers for ease of use and tuning.

Shift sets shift amount of speculars from root to tip.
Width sets width of speculars. The more the width the wider they are.

Usage:
1. Download and Install ssh_marschner_hair.otl (File->Install Digital Asset Library)
2. In SHOP context start typing ssh_marschner_hair_model and choose this shader.

Update: There are hairDiffuseExport and hairSpecularExport export variables so diffuse and specular data may be separated.

UPDATE:
Shader supports texture maps as well as ramps that allows to remap colors and opacity from root to tip.
Latest version of the shader is avaliable here:
ssh_marschner_hair

Attached Files

•  ssh_marschner_hair.otl   145.09K   535 downloads

Edited by ssh, 13 October 2011 - 01:36 AM.

[Hazoc]

Haha, that's insane. Thanks for sharing! Was it hard to implement ?

[Marc]

That's very cool, thanks for sharing Sergey!

M

[Macha]

Thank you, that's very amazing work!

[Jason]

Your results look nice and stable! Thank you very much for this lovely christmas gift. I do hope you can one day share the source code with us

[ssh]

Thank you guys!
I'm greatly appreciate your feedback!

Hazoc, on 27 December 2010 - 12:53 PM, said:

Was it hard to implement ?

Not very hard. It's not rocket science.

Jason, on 27 December 2010 - 06:20 PM, said:

I do hope you can one day share the source code with us

Yes, why not. I'll think about it.

[Hazoc]

ssh, on 28 December 2010 - 02:22 AM, said:

Not very hard. It's not rocket science.

That's right. But the shader is pretty huge, I've only done some simple ones. How do you start something like that ? Build first some of the modules indipendently and see that their contribution to the ouput looks correct or what ?

[Jason]

ssh, on 28 December 2010 - 02:22 AM, said:

Yes, why not. I'll think about it.

I'm sure the community would very much appreciate it

[ssh]

Hazoc, on 28 December 2010 - 09:33 AM, said:

How do you start something like that ? Build first some of the modules indipendently and see that their contribution to the ouput looks correct or what ?

Yes, something like this.

I definitely had to read this paper several times before understand anything.
Next, I figured out that there are simple things and there are complicated ones.

For example, compute R component is relatively very simple and computing TRT is much more complicated.
So, starting with simple ones, get proper results and then getting into more complex stuff.

If you have any questions - please ask.

[ssh]

Forgot to mention: there are hairDiffuseExport and hairSpecularExport export variables so diffuse and specular data may be separated.

[Matt_K]

Thanks Sergey, looks good!

Matt.

[Serg]

That is fantastic Sergey, Thanks!

S