Nested groups

bomastudio

Hi all, I need some help in understanding nested groups.I have to build something like as follows:

So I used:


@level[0] = SkecthUp.active_model.active_entities.add_group()
@level[0].name="LEVEL_0"

@sublevel1 = @level[0].entities.add_group
@sublevel1.name = "OBJECTS_TYPE_1"

@sublevel2 = @level[0].entities.add_group
@sublevel2.name = "OBJECTS_TYPE_2"



# loop code for geometry generation
i=0
n=5

@type1=[] # I waant to store OBJECTS_TYPE_1 into an array for further processing
@type2=[] # same ...
n1=0 # incremental number of OBJECTS_TYPE_1
n2=0 # incremental number of OBJECTS_TYPE_2

while i < n
    pts << [xj,yj,zj]  # xj, yj, zy getted from other part of my script
    if (layer=="TYPE_1")
        @OBJ_1a = @sublevel1.entities.add_group
        ent1=@OBJ_1a.entities
        @type1[n1] = ent1.add_face(pts)
        @type1[n1].pushpull(hpil,false)
        if n1<9
		@OBJ_1a.name= "OBJ_0" + (n1+1).to_s + "a"
	else
		@OBJ_1a.name= "OBJ_" + (n1+1).to_s + "a"
	end
	n1 += 1
    elsif (layer=="TYPE_2")
        @OBJ_2a = @sublevel2.entities.add_group
        ent2=@OBJ_2a.entities
        @type2[n2] = ent2.add_face(pts)
        @type2[n2].pushpull(hpil,false)
        if n2<9
		@OBJ_2a.name= "OBJ_0" + (n1+1).to_s + "b"
	else
		@OBJ_2a.name= "OBJ_" + (n1+1).to_s + "b"
	end
	n2 += 1
    end
end

Running my code I get an error

Error: #<TypeError: reference to deleted Group>

The error is on line

 @OBJ_1a = @sublevel1.entities.add_group

of the code above. What is wrong?

Dan Rathbun

As soon as you make an empty group.. you must ADD something to it in the next statement or two.
A cpoint is often used.

If you don't,.. SketchUp will delete the empty group automatically.

TIG

As Dan says... an empty group won't last for long.
Add something like this:
@sublevel1.entities.add_cpoint(ORIGIN)
immediately after making the group [you need to do it for every 'empty' nested group]...
You won't need to do it where you add a group into a group etc, as then that means the container-group is no longer empty as it contains a nested group!
Then to tidy up later, after there is some geometry inside the group, use something like:
group.entities.erase_entities(group.entities.grep(Sketchup::ConstructionPoint))
to delete the cpoint [substitute the 'reference' needed, where I have used 'group']

bomastudio

@dan rathbun said:

As soon as you make an empty group.. you must ADD something to it in the next statement or two.
A cpoint is often used.

If you don't,.. SketchUp will delete the empty group automatically.

Thank you Dan!!!

bomastudio

@tig said:

As Dan says... an empty group won't last for long.
Add something like this:
@sublevel1.entities.add_cpoint(ORIGIN)
immediately after making the group [you need to do it for every 'empty' nested group]...
You won't need to do it where you add a group into a group etc, as then that means the container-group is no longer empty as it contains a nested group!
Then to tidy up later, after there is some geometry inside the group, use something like:
group.entities.erase_entities(group.entities.grep(Sketchup::ConstructionPoint))
to delete the cpoint [substitute the 'reference' needed, where I have used 'group']

Thanks TIG!! Now all the world is clear as a sunny day!!!
I'm going to correct my code.....

bomastudio

THANXXXXXXXXX!!!! it works!!!!!!