VEX edge loop selection script tutorial Houdini

link with hip file and complete script drive.google.com/drive/folder...
With all the Houdini 19 cool features, let's do something not so exciting, but still useful and a good exercise in a vex.
0:00 end result
01:37 setup
04:27 converting group string to int array
10:34 theory behind getting edge loop selection
14:40 get edge selection points function
29:50 get next point function
37:20 using both functions to get loop arrays
55:24 getting single string as a detail attrib
1:02:37 make sure we run only valid edge selections
1:04:24 im out!

[@BehradDavoudi]

thank you! this was very useful

[@inspirationalgoosebumps6006]

My brain just exploded

[@mk.confid9054]

Hi nice tutorial, what plugin do you use for auto complete context?

[@viktors_anfimovs]

In vscode marketplaces just search vex.

[@catacombs3583]

What to do if group of edges already created prodcedurally and we dont have "basegroup" string?

[@viktors_anfimovs]

so what you could do is to create a detail attrib. lets say you have edge group convert it to detail string, imitating a manually selected edge group.
int edge_points[] =expandedgegroup(0,"single_edges" ); //get array of edge points
string edge_array[];
foreach (int index; int pt; edge_points){
if (index % 2 == 0) { //since we need point pairs, the expandedgegroup array should give us ordered points so we can just skip every second loop with modulus of 2
string pt_1 = itoa(pt);
string pt_2 = itoa(edge_points[index +1]);
string edge_pt_str = concat("p",pt_1, "-", pt_2); // imitate manual edge selection syntax
append(edge_array, edge_pt_str);
}
}
setdetailattrib(0, "edges", join(edge_array, " ")); //join string array into one string, and set it to detail attrib

[@catacombs3583]

@@viktors_anfimovs Thank you very much

[@jinjikong885]

My details attrib just not woring in my group , can you tell how you exactly transfer details attrib to the base group? That part is a little bit confusing for me.

[@viktors_anfimovs]

Go ahead and download the hip file in description. That should make things more clear.