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Hi, I have a character with nhair and Im trying to texture the hair with the same color as the base geometry, to do this I am trying to connect a uv proyection in the image texture node of the shader, but nothing happens, the hair get a random color, like a box proyection or something, also when I connect the "octaneImageTexture" node to the image texture list in the pxhair1 the hair render brown, without any texture color, your help would be much appreciated

abeoctane wrote:Hi, I have a character with nhair and Im trying to texture the hair with the same color as the base geometry, to do this I am trying to connect a uv proyection in the image texture node of the shader, but nothing happens, the hair get a random color, like a box proyection or something, also when I connect the "octaneImageTexture" node to the image texture list in the pxhair1 the hair render brown, without any texture color, your help would be much appreciated

- Unlike other Octane plugin, the Maya plugin is not able to transfer the underlying mesh UVs to Octane hair,
indeed the Maya plugin use arbitrary UVs for hair, unusable with Octane UV projected textures...

- It's possible to bake Maya texture color to this arbitrary UVs (Maya file connected to nHair shape shading color) to an empty Octane nHair bitmap texture node, ... but the workflow is very clunky and anyway Maya mess up the color as soon as you have more than one hair per follicle.

- If you are using the new Maya beta plugin, better to workaround the terrible hair plugin implementation:
you should use Xgen interactive, then cache hair to alembic then import the ABC in an "ORBX proxy" node in Maya,
then you would have correct hair UVs to use with Octane textures.

Hi calus, such a shame we got this bad hair implementation in maya, hope they fix it soon and give us xgen support, thank you very much for your help.

Hi calus, if it is not too bothersome to you, could you please share some details about the baking process to get the hair color from maya?, thanks a lot.

abeoctane wrote:could you please share some details about the baking process to get the hair color from maya?

Keep in mind that with this workflow, the hair color match the texture UV only if you have a very small clump base width, or if you have only 1 hair per clump


Add a Maya texture in the nHairSystem shading color.
Then you should see in viewport the texture coloring the opengl hairs, In the pfxHair transform create an Octane Material. In the diffuse (or other attribute color) create an octaneImageTexture. Leave the file path empty (this empty node will used by the plugin to bake the Maya colors) and clic 2 times on the little arrow icon to go back to the pfxHair transform tab. As the newly created ImageTexture node is still selected , clic on "add selected" button. That's it.

Thank you Claus for the tutorial.

Keep in mind that with this workflow, the hair color match the texture UV only if you have a very small clump base width, or if you have only 1 hair per clump

Actually, Octane for Maya support Maya's nhair Color Randomization and Diffuse Rand has some value by default. You can try changing it to '0" then it should fix the 1 hair per clump.
Regarding Xgen support, we would be looking into it as soon as this branch has a stable version.


Here is a quick video on nhair workflow:

BK wrote: Actually, Octane for Maya support Maya's nhair Color Randomization and Diffuse Rand has some value by default. You can try changing it to '0" then it should fix the 1 hair per clump.

No sadly this issue have nothing to do with color randomization :
Maya doesn't sample the color texture per hair but per follicle, so only the hair at the center of a clump are sure to get the correct color...
Also in your movie this only works because you use a particular case : a 1x1 plane,
but this won't work with any other mesh (just try with a torus for example).

Let me make the issue more obvious in this sample scene with a 20x20 plane : Color randomization is zero but as you can see hair colors doesn't match the underlying mesh texture UV .... Now if I scale the clump base to zero (so all hairs have there origin at the center of the clump) I get a perfect match, but obviously this is not a solution.
To be clear, this workflow never works for real life use-case,
the arbitrary Hair UVs make nHair/pfx useless with Octane4maya, when correct texturing is needed.

BK wrote: Regarding Xgen support, we would be looking into it as soon as this branch has a stable version.

Direct XGEN support would be nice, but please don't forget also that many implemented features in the development branch are just not finished :
just good for quick demo testing, but not usable in real life production.

Also as I explained in a previous post, Xgen-interactiv is already supported in the new Maya plugin trough the ORBXproxy node.
Workflow is : Xgen-interactiv > export builtin cache to alembic >create ORBXproxy node > import the ABC cache file and setup material in the ORBXproxy UI > render (much simpler workflow !)
The Maya caching feature for Xgen-interactiv ( alembic curves with correct UV and widths ) makes a way better job than the Octane4Maya plugin with pfx/nHair.

calus wrote:

BK wrote: Actually, Octane for Maya support Maya's nhair Color Randomization and Diffuse Rand has some value by default. You can try changing it to '0" then it should fix the 1 hair per clump.

No sadly this issue have nothing to do with color randomization :
Maya doesn't sample the color texture per hair but per follicle, so only the hair at the center of a clump are sure to get the correct color...
Also in your movie this only works because you use a particular case : a 1x1 plane,
but this won't work with any other mesh (just try with a torus for example).

Let me make the issue more obvious in this sample scene with a 20x20 plane :

nHairPerClumpColor.zip

Color randomization is zero but as you can see hair colors doesn't match the underlying mesh texture UV ....

maya_2018-07-06_10-16-22.png

Now if I scale the clump base to zero (so all hairs have there origin at the center of the clump) I get a perfect match, but obviously this is not a solution.

maya_2018-07-06_10-18-37.png

To be clear, this workflow never works for real life use-case,
the arbitrary Hair UVs make nHair/pfx useless with Octane4maya, when correct texturing is needed.

BK wrote: Regarding Xgen support, we would be looking into it as soon as this branch has a stable version.

Direct XGEN support would be nice, but please don't forget also that many implemented features in the development branch are just not finished :
just good for quick demo testing, but not usable in real life production.

Also as I explained in a previous post, Xgen-interactiv is already supported in the new Maya plugin trough the ORBXproxy node.
Workflow is : Xgen-interactiv > export builtin cache to alembic >create ORBXproxy node > import the ABC cache file and setup material in the ORBXproxy UI > render (much simpler workflow !)
The Maya caching feature for Xgen-interactiv ( alembic curves with correct UV and widths ) makes a way better job than the Octane4Maya plugin with pfx/nHair.

Thanks alot calus and BK, I tried with the new beta plugin and the alembic method, unfortunately the orbx proxy dont save any of the modifications I did to the imported alembic hair, every time I opened the scene the hair rendered white, I agree xgen support can be good

abeoctane wrote: I tried with the new beta plugin and the alembic method, unfortunately the orbx proxy dont save any of the modifications I did to the imported alembic hair, every time I opened the scene the hair rendered white, I agree xgen support can be good

To validate the changes in the proxy UI (ORBXproxy nodegraph) , you need to close this window BEFORE saving the scene. Be carefull this window can still be open but invisible : hidden behind the Maya window.

calus wrote:

abeoctane wrote: I tried with the new beta plugin and the alembic method, unfortunately the orbx proxy dont save any of the modifications I did to the imported alembic hair, every time I opened the scene the hair rendered white, I agree xgen support can be good

To validate the changes in the proxy UI (ORBXproxy nodegraph) , you need to close this window BEFORE saving the scene. Be carefull this window can still be open but invisible : hidden behind the Maya window.

Oh I see, yes the Ui is not very intuitive and I think it needs to autosave when I save my maya scene, thank you calus for clarify this.