Marschner hair model

[ssh]

Primary, Secondary, Overall spec all have bright colours, diffuse has a decent intensity which is a ramp from a very very light grey to almost pure white. What other parameters should i be messing with?

Nice wip I should say!

My suggestion is to increase diffuse component to get light colored hair.

Please try to increase Diffuse Intensity from default 0.01 to something like 0.7.

Also changing diffuse color from default 0.001 (almost black) to something like (1, 0.9, 0.8) will help.

I've used similar settings for light colored hair in my video.

[abvfx]

Yeah my setting with that last render were 0.8 on the diffuse intensity with it almost set to white. Maybe it had something to do with my lights? Dunno.

If i get time i will setup a simple scene to replicate it and you can tell me where im going wrong.(if you have the time)

[ssh]

If you post scene file I'll sure check it out!

[abvfx]

Cheers mate

Sry i took a while.

Here is a small file with a quick setup. Its using the latest version and i also put the SESI version in there to compare.

Any/all help is much appreciated

simpleHair.hipnc

[ssh]

Here is the blond render:

I've increased intensities. Did not touch the lights, just switched raytraced shadows to depthmap on topLight.

It turned out that my shader use slightly different way to compute diffuse then standard shader from SESI.

I'm using call to:

diffuseBRDF()

This way one may set diffuse roughness.

In standard shader we have for diffuse:

abs(dot(nN,nL));

I've made a version of my shader that computes diffuse in that way. Please download from this post.

Here is the comparison of diffuse components of both shaders:

simpleHair_diffuse_hipnc.zip

simpleHair_spec_hipnc.zip

ssh_marschner_hair.otl

[abvfx]

Thank you sir .

Any reason for using depth maps instead of raytrace apart from speed? I feel when it comes to fur than i get alot of pitted shadows and the resolutions get pretty insane .

Either way back to testing can once again commence .

[ssh]

[uPDATE] Added hairPaintExport variable that contains diffuse premultiplied by color.

Now there are four export variables:

hairDiffuseExport - contains diffuse.

hairPaintExport - contains diffuse premultiplied by color.

hairSpecularExport - contains specular.

occlusionExport - contains white color (1,1,1).

ssh_marschner_hair.otl

[ssh]

Thank you sir .

You are welcome!

Any reason for using depth maps instead of raytrace apart from speed?

Basing on my experience of rendering animated hairy characters I should say that raytraced shadows are pretty unusable with hair.

Because both of rendering speed and lots of flickering in animation.

And depthmapped shadows are fine, just set pixel samples to values like 3x3. Usual resolution is 1k or 2k, but it greatly depends on placement of your lights.

Hope this helps.

[jim c]

Hi there. I'm trying to use your shader on character I'm making that has long hair. I'd like to try and have dark hair, either a dark brunette, or even something close to black, with settings similar to your dark haired model in your first post.

But I'm completely lost as to what controls what. Any suggestions for how to tackle that?

[ssh]

Hi,

Sorry, I'm not sure I've understand your question properly.

Do you mean what are shader parameters?

Or something other?

[jim c]

Yes, the shader parameters. I went through the thread again and got a little more out of it, but there's still *alot* of parameters to fool around with. That's what I was confused with a bit.

[ssh]

For example: primary highlight's main parameters:

Is that a good explanation?

Edited July 1, 2011 by ssh

[Jason]

Just to be clear, phrenzy; I assume you're talking about deep shadows, not straight depth maps, correct? You don't wanna be using z-depth maps:) DSMs FTW

[abvfx]

Yeah maybe i didnt have transparent shadows turned on for those renders. Am i still right in thinking transparency with depth maps == Deep Shadows?

[zgrzewacz]

Hi!

I was trying to use yours shader on hqfarm and I've got some problems.

It is really strange thing - when I'm rendering simple test scene locally - everything works. While rendering locally, all otls (including yours) are loaded from network directory. I'm sure, that farm can read and load otls from this directory.

While rendering on farm, the shader takes no effect on object.

The only error that I get in hqfarm terminal is (using highest mantra verbose level):

'

Unable to get VEX code from:

opdef:/Shop/ssh_marschner_hair

'

In attachment there is simple test scene that doesn't work while network rendering.

Thank You and i'm waiting for your reply.

testlibotls2_pub.hip

[ssh]

Hi grzegorz!

Just tested your scene on my farm and it rendered without any errors.

We did not use HQueue, but I don't think this is a problem.

May I suggest you to check HOUDINI_OTL_PATH environment variable on render nodes?

It should contain a path to network directory with hair shader otl.

Can you please check if other custom otls works when rendering on farm?

[zgrzewacz]

hi sergey

Other custom otls are working fine on our farm except yours.

Thanks for your fast answer.

spasiba balszoje

[ssh]

Hm, this is a bit strange

Do the HOUDINI_OTL_PATH environment variable on render node contain the right path?

[zgrzewacz]

for sure

[symek]

...permissions bits.