Question about "open" groups.

CPhillips

My FFD plugin creates a group of construction points. If the user has the group open the position of the points (all entites) is given in world space not group space.

How can I detect if the group is "open"? Or is there some other way to get untransformed positions?

Thanks
Chris

Whaat

This might be what you want:

m=Sketchup.active_model
ents=m.active_entities

parent=ents.parent

if parent.class==Sketchup;;ComponentDefinition
   if parent.group?
       trans=parent.transformation
       p "in group #{parent.name}"
       p  trans.origin
   end
end

CPhillips

@whaat said:

This might be what you want:

m=Sketchup.active_model
> ents=m.active_entities
> 
> parent=ents.parent
> 
> if parent.class==Sketchup;;ComponentDefinition
>    if parent.group?
>        trans=parent.transformation
>        p "in group #{parent.name}"
>        p  trans.origin
>    end
> end

Thanks. That answers the first question "how to tell if a group is open".

But the code above doesn't work for me. "parent" is a ComponentDefinition and that class doesn't have a transformation. (unless i did something wrong?)

I found the instance of the group but when the object is open the .transformation is identity.

The real question I guess is if a group is open how can you get its real transformation?

Chris

AdamB

Unfortunately, I think you just have to observe them by adding an instance of this:


class MyInstanceObserver < Sketchup;;InstanceObserver

	def onOpen(inst)
		puts "onOpen"
	end
	def onClose(inst)
		puts "onClose"
	end
end

todd burch

You can tell if you are in Group or Component edit by comparing Sketchup.active_model.entities to Sketchup.active_model.active_entities. If they are the same, you are not in Group/Comp edit.

Todd

CPhillips

Ok, now I can detect that it is open. But how can I tell what the unopened groups transform is. As soon as a group is opened its transform becomes identity. I even tried to get it in a observer and by the time the onOpen is called it is already transformed.

todd burch

Post a small script that illustrates what you are having trouble with.

CPhillips

@unknownuser said:

Post a small script that illustrates what you are having trouble with.

Create a group and select it. Then type:

group=Sketchup.active_model.selection[0]
Then:
group.transformation.to_a.inspect

Note the transformation.

Now open the group and execute the same line.
group.transformation.to_a.inspect

When open the transformation will always be:
[1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0]

Jim

But the Group's transformation stays the same even if its entities are changed... so what's the point trying to get something you already know? Sorry if I'm missing the obvious.

todd burch

OK, you're right.

What are you trying to do? Can you use the group's transformation origin and apply that to any translation you need to do for your cpoints?

CPhillips

@unknownuser said:

OK, you're right.

What are you trying to do? Can you use the group's transformation origin and apply that to any translation you need to do for your cpoints?

I could if I could get the original transformation. But as I said its set to identity as soon as you open the group.

When I create the group of construction points I set an attribute that has its initial position in the group. Then the user opens the group, manipulates the points and I compare the new position to the position stored in the attribute. It works fine if the group is closed but if it is still open the points are transformed into world space instead of group space so I am comparing apples and oranges.

@jim said:

But the Group's transformation stays the same even if its entities are changed... so what's the point trying to get something you already know? Sorry if I'm missing the obvious.

The groups transform does not stay the same. Not only is the transform zeroed but the location of all the points is world relative instead of group relative. If I have a point at position (1,1,1) in a group when I open the group its position will be (1,1,1) + whatever the transformation.origin of the unopened group is. Not to mention the effects of rotation and scaling.

It seems when you open a group Sketchup transforms all the entities in that group by the groups transform and then sets the group transform to identity.

todd burch

I had a similar issue recently and I simply had to tell the user that the operation he was trying to perform was not allowed while in Group edit. This was because of the bugs dealing with working with groups and being out of context when in group/component edit.

That's the way the ball bounces.

CPhillips

@unknownuser said:

I had a similar issue recently and I simply had to tell the user that the operation he was trying to perform was not allowed while in Group edit. This was because of the bugs dealing with working with groups and being out of context when in group/component edit.

That's the way the ball bounces.

Thats disappointing.

Thanks Todd.

CPhillips

I found a work around but its a little gross. I don't fully trust observers not to crash Sketchup.

I put a entityObserver on my lattice group and then in onChangeEntity I store the current transformation in an attribute. Then when a user moves a point I check to see if the group is open (via observer) and if so I transform my control points by the inverse of the stored transform. That gives me a group relative point. whew.

Thanks for the help.
Chris

todd burch

I figured it out!

If your group is open, get any entity in the group, and do this:

entity.parent.origin

That will give you the origin of the group's transformation. Viola!

Todd

CPhillips

@unknownuser said:

I figured it out!

If your group is open, get any entity in the group, and do this:

entity.parent.origin

That will give you the origin of the group's transformation. Viola!

Todd

When I try that the parent is ComponentDefinition and that doesn't have .origin. Did I miss a step?

Chris

todd burch

Oops. Sorry.

entity.parent.insertion_point

Todd

CPhillips

@unknownuser said:

Oops. Sorry.

entity.parent.insertion_point

Todd

Ah! That does seem to work. Its only a point though, any way to get the rest of the transformation?

Thanks Todd!

todd burch

My hat of guessing says...

tr = Geom::Transformation.new(entity.parent.insertion_point)

Todd

todd burch

...but I don't think that will take care of any rotation.

Question about &quot;open&quot; groups.

Question about "open" groups.