Some edges not deleted!

Developers Ruby API
1

Dear Friends,

pt = [[0, 0, 0], [2, 0, 0], [4, 0, 0], [6, 0, 0], [8, 0, 0], [10, 0, 0]]
rpt = [[0, 8, 0], [2, 8, 0], [4, 8, 0], [6, 8, 0], [8, 8, 0], [10, 8, 0]]
grp = Sketchup.active_model.active_entities.add_group
for i in 0...5
  face = grp.entities.add_face [rpt[i], pt[i], pt[i + 1], rpt[i + 1]]
  face.reverse! if face.normal == [0, 0, -1]
  face.pushpull i + 1
  face = grp.entities.add_face [rpt[i], pt[i], pt[i + 1], rpt[i + 1]]
  face.reverse! if face.normal == [0, 0, 1]
end
grp.entities.grep(Sketchup::Edge) do |e|
  e.erase! if e.faces.first.normal == e.faces.last.normal
end

You can see result in attached picture.

Screenshot 2020-11-16 185326
Screenshot 2020-11-16 185326748Ă—631 32.5 KB

As you can see in picture some edges not deleted!!! Can you help me for this problem?
Thank you in advance.

2

Following code solve my problem but I don’t know why I have to run codes 2 times.

2.times do
  grp.entities.grep(Sketchup::Edge) do |e|
    e.erase! if e.faces.first.normal == e.faces.last.normal
  end  
end
3

If an edge has 3 faces - e.g. an internal partition face - then sometimes you code will fail once…
Repeating it then traps those exceptions.

If you want to delete the edges you show then consider using:

grp.entities.grep(Sketchup::Edge){|e|
  e.erase! if e.faces.length > 2
}
1 Like
4

This is your original stairs with internal faces.
image

(The rest is answered by TIG while I typed)

1 Like
5

Of course, my solution falls apart once you delete some edges, so subsequent edges tested don’t match…
You can collect them and do it in one go !
This avoids any redoing…

togos=[]
grp.entities.grep(Sketchup::Edge){|e|
  togos << e if e.faces.length > 2
}
grp.entities.erase_entities(togos) if togos[0]
2 Likes
6

The code snippet from TIG will erase more edges, than necessary.

In this particular case this one works better…

grp.entities.grep(Sketchup::Edge) do |e|
  e.erase! if e.faces.first.normal == e.faces.last.normal || e.faces.length > 2
end
1 Like
7

You can avoid this situation if you draw the side (profile) face, and pushpull in the direction of the Y_AXIS to the width of your stair tread.

:bulb:

2 Likes
8

Thank you all. I understand my problem and solution completely.