Face.clone

[kwalkerman]

Is there something that will achieve a face.clone or face.copy? Eventually I want something that will copy all information, including materials, textures, etc. At the moment, I'm just trying to copy the geometry. See the image below. The image on the left is the original face. The image in the middle is the result of creating a new face using entities.add_face(face.outer_loop.vertices). The outer geometry is maintained, but not the hole in the middle. Using entities.add_face(face.vertices) results in the shape to the right - not right at all.

As always, Thanks!

--
Karen

---

[kwalkerman]

So apparently, you can do face.clone, the challenge is having the face around long enough to do anything with it. I would like to add the cloned face to a group. Entities.add_face only accepts arrays of edges or points, not actual faces, is there any way to add an already defined face to a group? I if so, I might be able to determine what is happening with face.clone

--
Karen

[thomthom]

I'd create a copy face using the outer loop first, then iterate the remaining loops and add then, removing the inner face if the original doesn't have one.

[thomthom]

btw, are you generating the face yourself? If so, could you not create it as a group and copy it as many times you need then explode the groups?

what is the scenario here?

[TIG]

Forget about loops and the like...
First off you need to add the desired face to a temporary group
tgp=Sketchup.active_model.active_entities.add_group(face)
copy that group,
fgp=tgp.copy
explode the original temporary group so that the original face is put back unchanged.
tgp.explode
Now you have a group (fgp) containing a clone of the original face with its location, material[s], layer and attributes etc...

[thomthom]

I thought adding existing geometry to groups made SU go rampage and bugsplat?

[kwalkerman]

I think that creating it as a group (and I may have a few faces), copying the group and then exploding the group is my best option. I don't want to use the first method because if I have another face (or sub-face if you want to think of it that way) in the hole, and I copied the sub-face first, then deleting the center of the hole will delete the face in the middle.

It just seemed to me that there should be a simpler way to do this.

I just tried TIG's method, and it works, although I have had a problem creating and exploding groups using the webconsole. The exact same script that will splat in the webconsole will run fine if I create an external rb file. I think this may be fixed in the next release?

Thanks as always for your help!!

--
Karen

[Didier Bur]

Hi,
Here is my code for it, i used it a while ago and it seems to do its job, no matter the number of holes in the face

Call with: clone_face=face.copy(v,d,ents)

assuming face is a face objet, v param is a vector3d object (direction of copy), d is a distance of copy along vector v, and ents is an entities object (in what entities collection to add the copied face). Normal is preserved.

class Sketchup;;Face
def copy(vec,dist,ents)
  ov=[]
  vec.length = dist if dist != 0
  self.outer_loop.vertices.each do |v|
    if dist != 0
      ov.push(v.position.offset(vec))
      else
      ov.push(v.position)
    end
  end
  outer_face = ents.add_face ov
  inner_faces = []
  if self.loops.length > 1
    il = self.loops
    il.shift
    il.each do |loop|
      ov=[]
      loop.vertices.each do |v|
        if dist != 0
          ov.push(v.position.offset(vec))
          else
          ov.push(v.position)
        end
      end
      inner_face = ents.add_face ov
      inner_faces.push(inner_face)
    end
    inner_faces.each do |f|
      f.erase!
    end
  end
  return outer_face
end
end # Class Face

Hope this helps,

[TIG]

@thomthom said:

I thought adding existing geometry to groups made SU go rampage and bugsplat?

It does, BUT NOT if you make, copy and explode the group immediately - many of my tools use this method without issues. It will Bugsplat if you try and do too much with these grouping, and especially if you try and group entities across sets - try and see -it won't splat...

PS: The advantage of this method is that the face's material[s], layer and attributes are kept automatically.

[Didier Bur]

A little OT but this code will avoid bugsplat when creating a bunch of empty groups at once:

class Sketchup;;Entities

        alias add_group_su add_group
        def add_group(*args)
                g=self.add_group_su(*args)
                while g.class!=Sketchup;;Group
					g=self.add_group_su(*args)
					Sketchup.active_model.definitions.purge_unused
                end
				return g
        end
 end 

[Dan Rathbun]

@kwalkerman said:

So apparently, you can do face.clone, ... I if so, I might be able to determine what is happening with face.clone

Karen,

The .clone and .dup methods come from standard Ruby class Object, and create "shallow" copies. Ie, (from the book,) "the instance variables of the obj are copied, but not the objects they reference."

Anyway.. it does NOT matter, because all of the Sketchup::Entity and Sketchup::Drawingelement subclasses are NOT pure Ruby objects. They are C++ objects, that are only exposed to Ruby in whatever manner (ie methods,) that the API makers decide(d). They do not really have Ruby attributes (instance variables,) they have C++ properties that we can access only if the API exposes them (thru a getter or setter method.)

If you attempt to use the .clone or .dup methods on any C++ object, you will see a special "boo-boo" class returned:
f.selection[0] #<Sketchup::Face:0x6023f54> f2=f.clone #<Deleted Entity:0x6020188>

So don't use them. Really in the API they (.clone and .dup) should have been undefined for all the Sketchup subclasses that they don't work with, or overrriden with versions that do work (such as Didier's examples above.)

[cjthompson]

@tig said:

@thomthom said:

I thought adding existing geometry to groups made SU go rampage and bugsplat?

It does, BUT NOT if you make, copy and explode the group immediately - many of my tools use this method without issues. It will Bugsplat if you try and do too much with these grouping, and especially if you try and group entities across sets - try and see -it won't splat...

PS: The advantage of this method is that the face's material[s], layer and attributes are kept automatically.

.add_group(entities) should work fine as long as the entities are from model.active_entities.

[TIG]

OR any single ' entities' set - e.g. definition.entities.add_group(entities_already_in_the_definition_entities)

[cjthompson]

@tig said:

OR any single ' entities' set - e.g. definition.entities.add_group(entities_already_in_the_definition_entities)

but then you have to explode it right away (at least that's what it sounded like). If you only use active_entities, you can create it without having to worry about exploding it or bug-splatting SketchUp.

[TIG]

Yes you can create a group from entities immediately, and leave it made - just keep the entities-set the same fro all entities and the group itself

You don't have to use 'active_entities' - BUT just use one set fro all of the entities for the group and geometry...

Cross-threading entities causes splats.

How do you think some of my EEbyxxx tools work ?

What I was saying was, to to clone a face you can group it, copy the face-group and immediately explode the original group - that way the face is back where it was, and you have a group with an exact copy of the face in it - materials/layer/attributes etc...

[kwalkerman]

Didier - thanks for posting this. For my current purposes, I sometimes have another face bounded by the inner loops that I don't want to erase, so If I copy a bunch of faces together, and copy the inner loop faces first, then they'll get deleted when I copy the outer faces. So, creating a group, copying the group, and immediately exploding the original group is the best method for me.

Dan - thanks for the info on face.clone and face.dup. I saw <Deleted Entity: xxxxxxxxx> pop up in the ruby console, but I just assumed that the face was immediately deleted because it was placed on top of the other face.

--
Karen