expression question

[Lukich]

Hello again I was wondering if there's an expression in houdini that allows me to get a number of points in the group. Pointlist() returns a string with a list of those points, which is almost what I need. Is there a way to convert the pointlist output into an integer equal to the number of points?

thanks a lot,

Luka

[stevenong]

Hi Luka,

I would use a Delete SOP & delete points not in the group & use the npoints() to reference the Delete SOP.

Cheers!

steven

[Lukich]

Thanks a lot, Steven! Amazing, I started doing precisely the same expression when you replied It's working!!!

[hoknamahn]

Hello again   I was wondering if there's an expression in houdini that allows me to get a number of points in the group.  Pointlist() returns a string with a list of those points, which is almost what I need.  Is there a way to convert the pointlist output into an integer equal to the number of points?

thanks a lot,

Luka

14803[/snapback]

Try this:

float NPointsInGroup(string sop; string group_name) {
  float i = 0;
  string pt_list = pointlist(sop, group_name);
  float list_len = strlen(pt_list);
  float pt_num = 0;
  for(i = 0; i < list_len; i++) {
    if(substr(pt_list, i, 1) == "\x20") pt_num++;
  }
  return pt_num - 2;
}

[TheUsualAlex]

Try this:

float NPointsInGroup(string sop; string group_name) {
  float i = 0;
  string pt_list = pointlist(sop, group_name);
  float list_len = strlen(pt_list);
  float pt_num = 0;
  for(i = 0; i < list_len; i++) {
    if(substr(pt_list, i, 1) == "\x20") pt_num++;
  }
  return pt_num - 2;
}

14807[/snapback]

Interesting. Houdini's Custom expr function accepts hex value? I didn't know that.

[edward]

argc(pointlist(sop_name, group_name))

[hoknamahn]

Super!

[aracid]

nice one ed

aracid

[Lukich]

very nice, indeed. thanks a lot, guys!