Hi,
Sorry for all my questions i am new on Houdini and i have V-Ray for a few month and we start a big project (i am a little stressed). So i don’t know if it’s a bug or i just don’t know how to do that 
i try to get the alpha from my line, i get the color but the alpha not seem to work.
Thank you for your help.
Best Regards
Daniel
Houdin_hair_sampleri.zip (7.6 MB)
No it’s a bug I’m pretty sure, its easy to test if you create a grid with and apply material with a transparent png and use it for say diffuse and transparency, on cpu it works like you would expect, but on GPU it looks veeery odd hehe
mmmhhhhh but, not really a workaround , he take more than 3 min by frame to generate the wire .. 
so i really hope to found a solution for this.
i found another workaround it’s to use the color and map the color to the alpha and use a black and white and recolor the ramp for the color.
Hello @dpotuznik , are you trying to put @Cd as a color for the material and @ Alpha as transparency? If yes, than you could just use VRay UserColor and VRay UserFloat to get the attributes.
edit:
but for some reason everytime render is pressed the @ Alpha is different, I’ve added the issue and will message here once it is fixed.
Yes, it happens once on my side, but couldn’t get the reason of it. Anyway, I’ve logged it.
Hi again @dpotuznik , it looks like this issue is fixed in nightly build from today. I’m not getting any crashes or inconsistent @ Alpha attribute. Renders fine with HairSampler and with UserColor, V-Ray Material and V-Ray Hair material. You do not need colorToFloat or floatToColor or any kind of value converters, they are there only for internal use, all the attributes types are automatically converted during render.
hi, Perfect thank you very much .. this is why i love v-ray 
you rock.
Best regards
Daniel
Hi @chakarov,
Sorry i am pretty new on v-ray, i have an link for the nightly , but i don’t sure is the right one, i don’t see the folder for houdini anymore.
Thank you for your help.
Best Regards
Daniel
Hello @dpotuznik , once you’ve purchase the license you should get access to stable nightly builds. If you have some problems with access to them you should write to support@chaosgroup.com.
ah ok , yes i was in trial .. i bought now
Have nice day.
Best regards
Daniel
but i don’t see houdini on Chaos , i see all the other but houdini disapears from the list yesterday.
(i already have a annual liscence for modo also )
In this case you have to write to support@chaosgroup.com
you have to write to support
Hi @chakarov ,
I finnaly get the last build of Vray houdini.
but i still crashing, (it render a few time before crash this time ) but i still can’t get the Alpha from the userfloat is not working
Maybe i doing something wrong ?
see the picture in attachment on the viewport i have the Alpha but not on the render. ( idisconnect the color to better see the alpha)
I tried with the hair sampler but is not really take my ramp correctely
Here the project simplified
https://www.swisstransfer.com/d/107f5ac1-b3ae-4170-99ae-7cd4d6adb998
Thank for your help.
Best Regards
Daniel
Hi, it looks that the fix is not added to the stable nightlies. The devs should sync this and some more fixes soon.
Perfect , thank you!
do you think it will be at the end of this week ? ( i going to start the render )
note : strange limitation for indie user
According to devs, if there aren’t major issues stable nightlies should be updated this week.
It’s a sideFX policy, vrscene export is supported only with commercial Houdini FX license.
Thank you for your response
.> t’s a sideFX policy, vrscene export is supported only with commercial Houdini FX license.
i understand
