cpb

see attached,
compare edge directions & group.

Masoud
Is “SideFX Houdini” a complete 3D software

yes, but not for everyone; you will need to use vex/vops at some point.
I believe the original vision was to provide a suite of atomic operations that can be used in combination to create a wide variety of artwork. However:

- Work on these nodes seems to have slowed in favor of integrating 3rd party projects (with some exceptions) or re-arranging existing ones into HDAs and calling them new nodes.
- Some nodes have been left in an unfinished state for many years.
- Artists are increasingly relying on vex to make up for the shortfall in OP capability vs client expectations.
- There also hasn't been much progress in improving the capabilities of vex (like multi-dimensional arrays or file i/o).

So it seems the landing-gear is down for Houdini (or at least the idea of practical low-level OPs), but I don't see anything that comes close to replacing it. I suggest you get the most out of the program while its still eminent… also master vex and GLSL, as both will stand you in good-stead in the future.

try using ‘output radius attribute’ in the scatter sop.