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XGen Interactive Clump Input Points

Message 1 of 15
2711 Views, 14 Replies

XGen Interactive Clump Input Points


I noticed that the XGen Interactive Groom's Clump modifier has an "inputPoints" attribute and recently discovered that there's a "useInputPoints" attribute (CheckBox) hiding in the Extra Attributes. I haven't found any documentation about it so I tought I'd share this information here as I think it's a pretty good feature to have in a grooming toolset. 
Has anybody experimented with it?


Before using it in production, I would like to know more about the status of this feature. 
Is it an experimental feature? Is it safe to use? 

Best regards,


Message 2 of 15

Hi @renaud.bousquet


I'm actually not 100% sure on this. I'm looking at my clump modifier and I dont see the Input Points attribute you mentioned but I do see the one in the Extra Attributes tab. I noticed that if that is enabled it breaks the clump until its disabled and the preview is refreshed.


I passed this question along to development to try and get a more detailed response so I'll update here when I have more information!



Message 3 of 15

Hi @sean.heasley,


Thanks for having a look!


I forgot to mention the following details:

The inputPoints attribute is visible from the node editor when expanding the clump modifier node.
You can connect the outSplineData of an other spline description to it and then enabling the useInputPoints will get you different clump results.


Message 4 of 15

Hi @renaud.bousquet


While I don't believe there's any info in the docs, I think it is working as expected if you connect another description’s “Out Spline Data” to “inputPoints” of current description.

See the following node graph. As a result, the blue hairs root will be the clump point of the hairs (brown hairs). I attached a download my test scene (Maya2018) as well.









Message 5 of 15

 Oooo, I'm liking this so far, Sean, but I've run into a few snags.


So, I thought that sculpting on the blue hairs in your file would change the orientation or length of the clump, which it does not. Does it control only the grouping of the base of the clump? 


Is there a way to pump the blue splines' sculpt up the chain as well?  With the way it's set up now, I'd worry about recursion. EDIT: Yup, if you add a guide to the brown hair and try to push in the blue splines out spline data into the guide's in spline data, Maya locks up, weeps softly and tells you to go away. 


I experimented with your file since I'm not quite getting it.

  1. Changed the density of the blue clump hairs with the density brush. This looks really promising, as a way to control clump size based on body location. However, I couldn't get it to work with a ramp or a checkerboard pumped into the density mask, so I'm not sure if anything but the number and origin points of the blue splines are coming over to the hair at all.
  2. Sculpting on the brown hair, with the sculpt node under the clump. Works FANTASTIC, exactly how I want to groom clumps. They stick together beautifully. A+
  3. Changing length with the grab brush, with the preserve length option turned off. 
  4. Same as 3, with the brown hair turned off. What's getting me here is how is what I am doing on the brown description's sculpt layer affecting the blue splines' length and shape. According to the node editor, only the blue splines output data is going into the brown splines input points, so how is this data flowing backward? Is this intended? 
  5. Added a second clump, using the first clump as the control map. Works somewhat as expected, but the tips are REALLY locked down. I can't seem to get the secondary clump to deviate from the first at the tip, even mapping the control mask parameter.  The middles of the clump seem to respond, but the tips won't separate out. 
  6. Just a screenshot of the setup from 5.
  7. Bonus: If you have to change your CV count, make sure you rebuild both the guiding description (the blue) AND the hair. They seem to 'forget' about each other a lot.







Message 6 of 15

Hi @sean.heasley,


I know the feature is working. The idea behind my post was to share the existence of the feature, get some users feedback and try to find out more about it from Autodesk. Looking back at my initial post's question, what's the status of this feature? its current state lead me to think it might be unfinished (Checkbox hiding in extra attributes and missing documentation). Is it possible for you to get in touch in the devs concerning this?

Other that that, it seems to be working fine overall.
The only issue I experienced on my side so far is when modifying the width of the guides (the blue strands in your example) they are shrinking. Like if they were scaled down. They come back as they were as soon as I use a comb brush. It's a bit scary since you might think you have lost some of your grooming work.

Thank you for your help!

Message 7 of 15

Hi @Lindsey_Robbins,


I've had success with connecting a spline description's guide's Out SplineData into the spline description's clump inputPoints directly.

Unfortunately I cannot attach screenshot..

Hope it helps,

Message 8 of 15

Hi @renaud.bousquet


I actually have passed this along to development already :).


I can't say when the docs themselves will be updated but this is indeed on their radar work on it more in the future.



Message 9 of 15

Thank you @sean.heasley!

Message 10 of 15

Hi @sean.heasley,


Any news concerning this?


Many thanks,

Message 11 of 15

Hi @renaud.bousquet


It's in the works but most likely won't be updated until after we have released 2019 and the docs for that since that's the developers major focus at the moment.



Message 12 of 15
in reply to: sean.heasley

Hello everyone!


This seems like the solutions I was looking for weeks.
I would like to transfer the the Clump Guide Positions to the Linear Wire Positions. Is that possible?
Also, I am here to ask how the heck does one get to the XGen Node Editor? Could you please help me out or point me into the right direction. Thank you!

Message 13 of 15
in reply to: sean.heasley

Thanks you, I am trying to do the same effect but it does not work for me.

I can´t download the file... could you share it again?

Message 14 of 15
in reply to: animetria

Sean ,
Great solution  , butI can´t download the file .  can U please share the file one more time please 11

Message 15 of 15
in reply to: sean.heasley


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