Sorting primitives

[PVok]

Hello. I don't know Houdini very well yet, so I apologize if the answer seems obvious, but I haven't found any solutions on the forum pages or in any other sources.

A question about sorting. How can I sort the numbers of primitives sequentially? In order, say from the center.

 

 

If you use a node "Sort", he breaks out of the order.

 

 

And another question is optional. Maybe there are some simple ways to dilute the order, making it a snake or chaotic?

This is just interesting, but first of all I am interested in the question of the center.

 

 

If you can still catch the logic here. Take the ranges each 5. 5-9 15-19 and flip.

 

 

Howewer here it is already difficult to understand the logic.

 

 

But it would be great if there is a tool that can do this. I would be happy to hear your ideas and suggestions. At least which way to look.

 

Edited February 7, 2021 by PVok

[Aizatulin]

Hi,

for these kind of tasks you can use attributes, which can be stored in the geometry. The sort sop has the option "primitive sort" -> "by attribute". The result strongly depends on the attributes you set. In your case you can probably combine two attributes. The prim distance to the center prim (by point and not edge incidence) and the direction from the center. Here is an example using two different methods, to get the distance from the center (probably there are better ways), the other attribute uses the xyzdist() function to a circle. Once you have the attributes you can combine them by just adding them. Since the direction ist between 0 and 1, the distance attribute which is a count (0,1,2,...) will dominate.

prim_sort_spiral.hipnc

[Librarian]

you have File  here Value and policy iteration
https://www.cis.upenn.edu/~cis519/fall2015/lectures/14_ReinforcementLearning.pdf
https://www.cs.upc.edu/~mmartin/Ag4-4x.pdf