Hair Shaders NEED HELP Tweet

[Jolbertoquini]

Hi Guys,

I'm writing to ask some questions about hair to get the right result and control, Please don't hesitate to provide some screen shots and etc, at forum I saw already a discussion about that and doesn't answer really clear and the shader on Live DB ( is not at level as other render engines) I know Octane could have a proper shader if we compose then.
So I use for instance one of the best hair shaders I saw so far I like Arnold one but Renderman is looking more clear simple.
https://rmanwiki.pixar.com/display/REN/PxrHairColor On this link you can see color about melanin tons and random colors

I did a render on Octane try to simulate the same look here:
https://vimeo.com/218128407/70614e368d

What is missing? I think is Maya Plug issues! I can't export Orbx with hair, the file are coming without Hairs... I can add the colors "along the hair" with the node "octaneWTexture" but I can't at same time add random color "per follicles" doesn't work in Maya at all with the latest plug. This would give me the opportunity to create effects as "stray density" hairs getting older or variation on the melanin.

At Forum before "Mojave" propose me to use a noise texture, but this doesn't work at all cause the noise is add along the hair and doesn't react as before per follicles maybe is a option on standalone for that but Maya plug doesn't allow me to do that.

Please any answer for a solution? Maya plug dev take a huge time to provide something correct and for us at pipeline can be a big trouble ( I don't want wait one month to get something right in maya)

maybe I will export hairs from other softs and try at Standalone later...

Or could you guys give one example file with hair and color add per follicles and at same time along the hair?

Cheers,
JO

[Jolbertoquini]

ps... Just some extra information...

Just a quick question? "Hair length is the W" info and hairs "Segments count" is based on follicles basically per hair info.
For Maya the options doesn't work, I need try on Standalone to be sure.

Best,
JO

[Jolbertoquini]

Hi Guys,

Pascal help me out so is about UV projections is working for me now. just to let you know.

Best,
JO

[mojave]

Sorry for the late reply. Could you please let us know what was wrong so it can also be useful for other users?

Thank you.

[calus]

Sorry for the late reply. Could you please let us know what was wrong so it can also be useful for other users?

This is a bug/limitation of the Maya plugin.
In the Octane for Maya 's hair primitive implementation, the hair UV data is not sampled from the underlying mesh:
Unlike in all other plugins, Hair UV value are used to store arbitrary double index per hair.
This was done by JimStar to re-use a Maya mecanism where Maya assign one RGB value per hair,
so the plugin bake these RGB values in a temporary image texture with pixel coordinates matching the U and V arbitrary values.

The workflow to use this Octane for Maya "feature" is incredibly convoluted, the implementation is very buggy and have so many limitations that it's not usable for any advanced work.
But it was enough for Jo to be able to mix textures driven by UV and W, (even if UV is arbitrary, it can be used with noise to add a random variation per hair).

[calus]

BTW, it would be simple to fix this problem in the Maya plugin and finally make Octane textures using UV projection with hair useful for something (while preserving the per hair Maya Color baking support) :

Instead of using an arbitrary index array for Hair UV values, the plugin should just use the UV values from the underlying mesh (closest surface UV sampling is very simple in Maya API ),
or at least we should be able to set the hair UV values ourselves as for now it's a black box.

[Jolbertoquini]

yes, agree some work need to fix this but is most Maya issue. If need make a "tiger" for example and the fur need to have a colour based on the texture is not possible to achieve with Maya plug doesn't work for us. and this is kind of basic feature.

cheers.
JO

[abeoctane]

Hi Guys,

Pascal help me out so is about UV projections is working for me now. just to let you know.

Best,
JO

Hi Jolbertoquini, do you know another possible way to render hair with uvs within maya?, or do you know how can I freeze a projection so the texture dont move?, thank you.