Random Select within Group

[inversionstudio]

Hi guys, I'm having an issue that I have never been able to solve in houdini.
I have a bunch of leaves under the primitive group 'leaf' each made of 13 polys.
How do I randomly select whole leaves in this group and add them to a new group....and can it be done without using VEX?

At the moment, when I random select polys with group-range its just randomly selecting individual polys across all leaves.

Thanks

[anim]

assuming each leaf is unique set of connected polys you can use Assemble SOP, check Create Packed Geometry and Transfer group: leaf

you will get one packed primitive per each individually connected piece of geo and also pieces that were previously in group leaf will still belong to it so then you can filter down further, but now dealing with just one prim per leaf

[inversionstudio]

Hi anim, thanks for taking the time to reply, its much appreciated.  I still consider myself a newbie to houdini even though i've been using it for 6months ;-)

I feel your solution is completely correct but I just cannot figure out what steps to take next. 

The assemble node has given me the following in the geo spreadsheet:




I am now trying to add these new random leaves to 4 different groups. 
My brain naturally steers towards group-range, attr-randomize, and a normal group node with '@leaf>####' - but I feel my thinking with houdini is sometimes completely off.

What am I doing wrong?

Many Thanks

P.S.:

Even with this whole problem, I feel that a 'group-random' node would work wonders.  Select your point/primitive group and then adjust the random slider to select random parts of that group.
I see that you have achieved 'Grand-Master' status  - Do you know of any useful tutorials that could help me stop thinking like an artist and more in houdini terms?......I'm already subscribed to the following channels on YouTube:

- Entagma
- hipflask
- Rohan Dalvi
- houdini kitchen
- simon houdini

Edited February 16, 2021 by inversionstudio