select vertex by Z axis

@titane357 - "Yes, looks

@titane357 - "Yes, looks someting I wanted, but is the "loop" word that cause some misunderstanding :-))"

Yes, I think so "loop" word cause some misunderstanding. Thank you for noticed that! Poly ops Loop has no axis option and where is clearly visible so it used different method. I just tested the script only on primitives and the effect looks like loop. Maybe you will suggest a better name for the script? :)

"Something I don't understand is why need to pick an object ? It should work on selected object(s)... Can you explain ?"

I guess when people working on SubObject Level they works on single selected object. Else, of course I can extend the script to work with more than 1 selected object. And of course it would complicated the script a little, but why not... just say if you need this extra :) Now in the script you can see so my function is "independent" of the rollout, ie it can be used alone (without ui). Function has 3 argument: obj (mesh or poly - single node), axis (integer index 1,2,3 where 1=X, 2=Y, 3=Z) and divergency (float threshold). So same example loop for array of selected scene objects will be:
for i in selection do SelectVertLoop i 3 0
So tell me do you want to add this option in the rollout.

@harumscarum - "Thank you!! is it possibe to make it work with Edit Poly?"

Maybe, but at least I don't know how. I use the MAXScript only 6 months and just learn from the official Refernce. What I know is that Edit Poly is a different class of Editable Poly and has some different methods, but I don't find them in the Reference yet. Every help in this task is welcome or at least direct me where to look, thanks in advance.

Yes, looks someting I

Yes, looks someting I wanted, but is the "loop" word that cause some misunderstanding :-))
Something I don't understand is why need to pick an object ? It should work on selected object(s)...
Can you explain ?

I think that harumscarum

I think that harumscarum wants a script to select vertexes sharing same z position (with a threshold) to architectural purpose (I think : I need this tool too), so loops are not so helpfull...