How to add entities to a nested group?

[TIG]

Last things first...
Assuming the next two objects mentioned are in the same 'context'...
A group variable ' group1' is named "mygroup1", it's on layer "XXXX" and has material "red" etc. This is the group we are adding to
A group variable ' group2' is named "mygroup2", it's on layer "AAAA" and has material "banana" etc. This is the group we want to add.
You add a temporary group thus:
newgroup=group1.parent.entities.add_group(group1,group2)
At this point variable ' newgroup' has name="", layer=nil and material=nil etc.
When you explode 'group1' all of it properties and attributes vanish with it [properties reside with the object NOT its variable]... UNLESS you save the properties/attributes BEFORE you do the explode thus:
name=group1.name layer=group1.layer mat=group1.material
etc
NOW you can explode group1, change its referring variable to the temporary group...
group1=newgroup group1.name=name group1.layer=layer group1.material=mat
etc
NOW for all intents and purposes the group is still group1 [its 'id' has changed but nothing else].
So you end up with a group variable ' group1' named etc exactly as before containing the same entities PLUS ' group2'...
You can also explode group2 if desired...

You say faceEntities is under model.entities. rootGroup is under model.entities. groupGroup is already under rootGroup...
BUT newGroupGroup = rootGroup.entities.add_group(groupGroup, faceGroup) [note the removed () after entities - not correct !!!] will add a group to rootGroup's entities, and remember that at this point in your code rootGroup is now a pointer to what was newRootGroup... which you have just made inside @model.entities from the original rootGroup and [ruby:1upcmdm6]faceGroup[/ruby:1upcmdm6].
You are therefore adding two things into this [ruby:1upcmdm6]newGroupGroup[/ruby:1upcmdm6] ... [ruby:1upcmdm6]faceGroup[/ruby:1upcmdm6] which IS in there as you have just added it AND the mysterious [ruby:1upcmdm6]groupGroup[/ruby:1upcmdm6] BUT newRootGroup [now referred to a rootGroup] was made from [ruby:1upcmdm6]faceGroup[/ruby:1upcmdm6] AND rootGroup which you then exploded after it was added - so unless [ruby:1upcmdm6]groupGroup[/ruby:1upcmdm6] was already inside that and is therefore now inside the now called rootGroup after the explosion, AND you had previously referred explicitly to it BEFORE all of this - which is NOT shown in any of your code - then it WILL fail - if you have made a reference to an 'object' that seems to have appeared from nowhere and therefore ==nil.
Do you have a handle to this 'object' set up before this code snippet ?
You are perhaps onfusing the groups' references [variables] and their actual names [which appear in the Outliner]... So it may be named 'groupGroup' but is there a variable called 'groupGroup' that is pointing at it ?? There's nothing in your code to show it...
Try tidyinh your syntax [remove unneeded () etc] and check that everything is properly 'referred to' by variables -
which can share the objetc's names but need to be called explicitly.
Also note that making a new group [unlike making a copy of it] defaults all of its properties/attributes - and you have to transfer them to its 'clone'...

[draftomatic]

TIG, I really appreciate your help, but I still can't see that I'm doing anything wrong.

I've made a small example script that emulates my bug. Could you take a look please please?

---

test_group_bug.rb

[TIG]

Try this...

# Testing group nesting
### with TIG edits ###
  model = Sketchup.active_model
  entities = model.active_entities ### NOTE; 'active_'
  pts = []
  pts[0] = [0, 0, 0]
  pts[1] = [100, 0, 0]
  pts[2] = [100, 100, 0]
  pts[3] = [0, 100, 0]
  face = entities.add_face(pts)
  faceGroup = entities.add_group(face)
  faceGroup.name = "faceGroup"
  ### A GROUP REFERRED TO AS 'faceGroup', NAMED 'faceGroup'.
  ### IT CONTAINS THE FACE AND ITS EDGES - THEY ARE COPIED IT THEY ARE 
  ### STILL NEEDED IN THE ORIGINAL ENTITIES...
  rootGroup = entities.add_group()
  rootGroup.name = "rootGroup"
  ### A GROUP REFERRED TO AS 'rootGroup', NAMED 'rootGroup'.
  newGroup = rootGroup.entities.add_group(faceGroup)
  newGroup.name = rootGroup.name
  ### THERE'S NOW A GROUP REFERRED TO AS 'newGroup', BUT CALLED 'rootGroup'
  ### INSIDE IT IS A GROUP REFERRED/CALLED 'rootGroup'
  ### WHICH CONTAINS A GROUP REFERRED/NAMED 'faceGroup'
  ### WHICH CONTAINS THE 'face' ENTITIES...
  ### NOW DO WHAT YOU WANT...
###

[draftomatic]

@tig said:

Try this...

Try what? I did all of this in my code! I also want to nest faceGroup one level deeper, into "groupGroup."

As I said, getting faceGroup inside of rootGroup isn't a problem. It works using your trick. But I need it to go one level deeper, into groupGroup, and it's not working!!!

You stopped the code RIGHT BEFORE the point where I don't know what's wrong... And you took out the part with groupGroup, which is my entire problem!

Your code does this:

Please TIG or someone else, can you tell me specifically in my code, i.e. what line and WHY, am I doing wrong? I posted the example which reproduces my bug. What am I doing wrong? This bug has been stopping me for a week now... it's getting ridiculous!

[TIG]

This 'groupGroup' must be inside the same context as 'faceGroup'... OR...

You already have

rootGroup** IN model.entities
AND
face IN faceGroup IN newGroup [also named 'rootGroup'** BUT it is a different group] IN model.entities

so simply use:

groupGroup=newGroup.entities.add_group(faceGroup)
groupGroup.name="groupGroup"

face IN faceGroup IN groupGroup IN newGroup [named 'rootGroup'**] IN model.entities

OR you add another a group to model.entities

groupGroup=entities.add_group(newGroup)
groupGroup.name="rootGroup" ###***

face IN faceGroup IN newGroup [named 'rootGroup'] IN groupGroup [named yet another 'rootGroup'*] IN model.entities

You just have to decide which groups contain which.

Naming groups with the same name is plain confusing - why do it ?
Give them each a unique reference and at the end name them appropriately...

[draftomatic]

Okay, you're just confusing me now, and what you're describing doesn't work for my situation. groupGroup already exists, and rootGroup already exists. I'm only creating them again in my example so that it can stand alone. So doing anything like groupGroup=newGroup.entities.add_group(faceGroup) isn't acceptable, because groupGroup is ALREADY THERE.

Look TIG, can we get a bit simpler? Can you look quickly at test_group_bug.rb? I just simply don't understand why this line:
LINE 49: newGroupGroup = rootGroup.entities().add_group(groupGroup, faceGroup)
is breaking my code. As far as I can see, this is EXACTLY what you've told me to do. The contexts of groupGroup and faceGroup are identical (faceGroup.parent = rootGroup, and groupGroup.parent = rootGroup... I've checked).

Moreover, the SAME CODE works several lines up, when I do the SAME THING, except in model.entities instead of in rootGroup. I'm very confused, and I need a straightforward answer. What EXACTLY is wrong about that line of code?

[TIG]

The 'groupGroup' group DOESN'T really exist... except that you have made an empty group [too early] with that reference.
Adding that empty group so early on into the mix and then trying to 'move' it into another group only confuses things.
IF you already have a non-empty group with that reference then it's OK... but if not only make it when you need it otherwise.

If you still can't get your head around this then please post a simple before and after set of uniquely named objects with their hierarchy - e.g.

modelEntities=model.active_entities

CONTAINING [at least] groupX [an existing group that isn't empty] and face [a face]

OR ANY OTHER entities set with common objects you are to 'group' ?

groupX > modelEntities
face > modelEntities

WHICH BECOMES faceGroup = modelEntities.add_group(face)

face > faceGroup > modelEntities

THEN group1 = modelEntities.add_group(faceGroup, groupX)

face > faceGroup > group1 > modelEntities
groupX > group1 > modelEntities

THEN group2 = group1.entities.add_group(faceGroup, groupX)

face > faceGroup > group2 > group1 > modelEntities
groupX > group2 > group1 > modelEntities

THEN group3 = group2.entities.add_group(groupX)

face > faceGroup > group2 > group1 > modelEntities [STILL THE SAME AS BEFORE]
groupX > group3 > group2 > group1 > modelEntities

TO SEPARATE THE ENTITIES INTO SEPARATE GROUPS ETC ETC...

YOU CAN GO ON AND ON...

This has no 'names' just references to groups etc - you can add those later...

[draftomatic]

@tig said:

The 'groupGroup' group DOESN'T really exist... except that you have made an empty group [too early] with that reference.
Adding that empty group so early on into the mix and then trying to 'move' it into another group only confuses things.
IF you already have a non-empty group with that reference then it's OK... but if not only make it when you need it otherwise.

In my real code, there is already a CPoint inside "groupGroup." If you think it's a problem that groupGroup is empty, then fine, I just tried adding a CPoint to groupGroup in my example script. Still broken.

@tig said:

If you still can't get your head around this

Sir, my head is wrapped around this problem about 9 times already. I feel like you think I don't understand, but I do. I understand every word you have written, and I keep telling you, "I'm doing that, I'm doing that. Look at my code, look at my code."

@tig said:

please post a simple before and after set of uniquely named objects with their hierarchy - e.g.

I did this already. Look at my script!!! Look at my screenshots!!! I am creating rootGroup and groupGroup. That is my hierarchy.

I'm going to repeat my question again. What is wrong with line 49 of my previous example script? I COMPLETELY understand EVERYTHING you're telling me, and I believe I'm doing it, but it's still broken, and I don't see why!!!!!!!!!!

[TIG]

Aaargh... in your sample code you 'magick' a group out of 'thin air' [groupGroup] and then you add it into a group within a nested group. IF that does exists it certainly isn't inside the 'newRootGroup' [retitled 'rootGroup'] entities as you've just created that - so it will ultimately splat - you ARE cross-threading entities.

Please try recasting your code [ignoring names and reusing references [variables] as it's getting confusing] in a way I outlined...

[draftomatic]

I think TIG gave up on me...

[draftomatic]

@tig said:

Aaargh...
Please try recasting your code [ignoring names and reusing references [variables] as it's getting confusing] in a way I outlined...

Argh indeed!

Here it is - as simple as I can make it. This is 14 lines of code. Now tell me, what is wrong?

The heirarchy is: model.entities -> group1 -> group2
After the code finishes, it should be: model.entities -> group1 -> group2 -> faceGroup -> face+edges

You can see that I'm creating these groups here, so there's no "magick!"

` # Testing group nesting

model = Sketchup.active_model
modelEntities = model.active_entities

Create a face

pts = []
pts[0] = [0, 0, 0]
pts[1] = [100, 0, 0]
pts[2] = [100, 100, 0]
pts[3] = [0, 100, 0]
face = modelEntities.add_face(pts)

Create root group

group1 = modelEntities.add_group()

Nest group2 inside group1

group2 = group1.entities.add_group()

Create group for faceGroup

faceGroup = modelEntities.add_group(face)

Nest in the first level

newGroup1 = modelEntities.add_group(group1, faceGroup)
group1.explode()

Repeat to get it to the second level deep

newGroup2 = newGroup1.entities.add_group(group2, faceGroup)

group2.explode() # This crashes SketchUp`

[Chris Fullmer]

You are exploding group1 though. That does seem right to me. I can't look at it right now, but I probably can try later tonight.

Seems like you should make a group and add the face data to it. Then make a group and add the facegroup to it. Then make a new group and add the other group to that. I'm sure that is exactly what you've already tried. I'll see if I can write up a fully working sample (unless someone else beats me to it).

Chris

[draftomatic]

Thank you very much Chris. And thanks to TIG too, even though I'm pretty sure he's moved on to bigger and better threads than this =D

[draftomatic]

Check it out. I have all these groups (group2 - groupN), under a root group (group1). And then I have faces, which I want to group with edges (faceGroup), and place in a nested group (group2 - groupN). There could potentially be many faceGroups, as shown in the picture...

HOWEVER... my example script 2 posts up is a simplified version of this, with only one nested group (group2), which is initially empty.

Clear enough?

---

[thomthom]

I'm confused by all this...
Why are you not creating the entities directly into the appropriate group instead of trying to move them from group to group?

[draftomatic]

@thomthom said:

I'm confused by all this...
Why are you not creating the entities directly into the appropriate group instead of trying to move them from group to group?

Because, my "real" code gets the faces by way of the user clicking a context menu on an existing face and clicking my plugin's option. So, the face is already there, but my example script is emulating this by creating a face inside of model.entities first...

[thomthom]

ok...

What about:

1. user pick face
2. group the face ( group1)
3. get the definition of the group ( group1.entities.parent)
4. add a new instance of the group into the group you want it
5. erase group1

When you have the group instance you can use entities.add_instance to add a copy of the group.
It might avoid the problems if using .add_group with entities as argument and exploding.

[draftomatic]

@thomthom said:

ok...

What about:

1. user pick face
2. group the face ( group1)
3. get the definition of the group ( group1.entities.parent)
4. add a new instance of the group into the group you want it
5. erase group1

When you have the group instance you can use entities.add_instance to add a copy of the group.
It might avoid the problems if using .add_group with entities as argument and exploding.

Oh... tricky. I'll try that tomorrow.

[thomthom]

# picked_face is the face the user selected
# group2 is the destination group
group1 = picked_face.parent.entities.add_group( picked_face.all_connected )
group_def = group1.entities.parent
group2.entities.add_instance( group_def, group2.transformation.inverse * group1.transformation )
group1.erase!

[draftomatic]

YAY! Thanks a ton thomthom, your solution works.