XGen Interactive Groom

[Sacha]

ok, it works so far.. =) But I have some issues with the VRayHair3Mtl.
Is it possible to use a ram or an image to color the hair? And so I have any option to color the tips other than the roots (also with an image or any other node)?
So far it´s a lot of fun to work with this combination.. xgen is getting a great util and I'd love to keep working with it if I'd get the hair coloured in different ways...
keep up that great work... It´s really a pleasure to have developers working so close to their customers!!!

[Sacha]

I meant ramp ^^

sorry for posting to correct myself but the edit function doesn't work for me...

As the title says: I'd like to use a "ramp" for colorization =)

[Algehov]

ok, it works so far.. =) But I have some issues with the VRayHair3Mtl.
Is it possible to use a ram or an image to color the hair? And so I have any option to color the tips other than the roots (also with an image or any other node)?
So far it´s a lot of fun to work with this combination.. xgen is getting a great util and I'd love to keep working with it if I'd get the hair coloured in different ways...
keep up that great work... It´s really a pleasure to have developers working so close to their customers!!!

I havnt tried the new nightly for interactive grooming yet.
But in "old" XGen you plugged a VrayHairSampler node into the v-coord of a ramp with DistanceAlongStrand, to get a ramp to control the color along the lenght of the hair. (There is also a RandomByStrand, that works the same way).
Did you try that?

[yolov]

The hair sampler should work just as well for the interactive groom splines as it does for maya hair.
Here's a short tutorial on how to set it up: https://docs.chaosgroup.com/display/...+Texture+Setup

[Sacha]

Ah okay... thanks guys, I wasn't aware of that! So I get the color from root to tip solved. But is there also a way to place a file node to get the color, dependent to the uv-layout from the object?
I'm not sure if you understand what I'm talking about =) e.g. I have a leopard modeled and want to give it hair with a leopard pattern, is it possible to have the hair grow in that color, the object is textured with? Like vrayfur does?.

[yolov]

I won't have time to check this for xgen until next year, but I can tell you how to do that for mayaHair. In hairSystemShape you can find a "shading" section with a hairColor paramter. You can plug in it the same texture that is used for your base object. Then read that info with the "hairColor" output from hairSampler and pass it to any plug of any shader. I need to see how to do that for xgen, but if it's possible, it shouldn't be much different.

[Sacha]

with mayaHair it works fine but I wasn't able to get it with xgen. When I take the haircolor from the sampler node I just get black. The xgen doesn't have a "shading" section like the MayaHair does. and I guess the vrayhairSampler tries to get it from there?

I wish you guys all the best for the new year!! take care..

[Algehov]

I havnt tried on how it works with XGen interactive grooming and Vray, as its abit different from standard XGen. We havnt moved to 2017 in our pipe. But ill try add the new nightly next week and see if I can figure out the differences.
In standard difference, you can add Custom Shading Parameters under the Preview/Output tab. There you can a parameter called root_color and set it as color, not float. You can also add a tip_color if you want a separate texture for the tips.
As XGen doesnt work with textures, but rather ptex files, you will have to convert your texture to ptex. This is easly enough to do in the xgen UI however.

Under your root_color parameter, press the down arrow next to the expression key, and click Create Map. (Its prefered to have a lambert1 material on the mesh that xgen is genereated on, as sometimes this fails else. You can just swap back to the correct shader after).
When you clicked Create Map, you wil get a paint tool. You can now either decide to paint your mask/color on your mesh, or you can choose to load a texture. Do this by selecting the file-node that should have been created and linked to the base mesh. Add a texture you wanna use to that file node. And then press the Save button in you custom shading parameter that you created in the XGen window.
This will convert that texture to ptex, and hook it up in the correct for the shading parameter.

Now whenver you just plug a vrayHairSampler straight into diffuse, as if it was a file texture, it will find that ptex file in root_color (which cover the whole hair btw, not just the root. Until you also use a tip_color).
It will show black in the shader ball, as it cant read the ptex file for that. But it should render properly.

Now, where they moved it so you can add a root_color parameter in Interactive Grooming Xgen I have no idea. I will have to check. But if you cant find it (or if chaosgroup has no way to do this in interactive grooming yet), you should be able to convert your interactive groom to a standard XGen and you can do it there.
That removes half of the new fun however.

Let me know if that didnt make sense, or if maybe some pictures could make it clearer.
Happy new year!

[moshev]

Hello,

XGen Interactive Groomable Splines don't offer the same color mapping capabilities as regular XGen. From V-Ray's point of view, it's a completely new hair system that's XGen only in name, i.e. it shares nothing with our support for classic XGen, so you're not able to reuse your ptex maps at all. Additionally, there is no way to assign any kind of color map to the hair like you can with classic XGen.

However, you will be able to simply assign a regular file texture for color in the hair material (or two textures via a ramp, controlled by distance along strand obtained from VRayHairSampler, etc.), because the UV coordinates of the strands are taken from the point on the surface from which the strand is generated. This is not yet supported, but will be very soon.

Hope this helps,
moshev

[Algehov]

Thanks for the update moshev!

Great news about being able to assign a regular texture, as its a bit of a hassle having to convert ptex files all the time, so this should speed up look dev by a lot!
Please keep us updated when it will be supported. Im greatly looking forward to that.

Cheers,
Simon

[Sacha]

That´s great to hear! Very much looking forward to that, but for now it´s already a lot fun to work with xgen and vray!

[Sprawl]

Hi,
I'd like to try the new interactive groom splines with vray, the new groom are very intuitive and more simple to use with dynamics.
How can i access to nightly builds ?

Thank you

Alex

[Sacha]

Hello,

However, you will be able to simply assign a regular file texture for color in the hair material (or two textures via a ramp, controlled by distance along strand obtained from VRayHairSampler, etc.), because the UV coordinates of the strands are taken from the point on the surface from which the strand is generated. This is not yet supported, but will be very soon.

Hope this helps,
moshev

Any news about that?

[FSGFX]

is there something in the nightlies for xgen we could testdrive..?

[yolov]

Yes, you can test the nightlies with xgen interactive groom splines.