How to find a group?

[lothcat]

Hi all,

This is such a simple question that I feel silly asking it, but I simply can't figure it out. I'm writing a plugin, and I want to calculate the volume of an object, and I know sketchup can do that if the object is a group.

Basically, the user right-clicks a selection to run my plugin, and I want to make that selection a group, calculate the volume, and then output it. I know how to get their selection, and I know how to get the volume of a group, but I don't know how to tell if their selection is a group or how to turn it into one if it isn't.

Any help would be appreciated!

[TIG]

Because it's working on a user's selection then all of the selected entities are in the active_entities context and you won't run the risk of a BugSplat by making a group from them directly [this is advised against usually but try it].

model=Sketchup.active_model
ents=model.active_entities
ss=model.selection
group=ents.add_group(ss.to_a)
volume=group.volume
group.explode

'volume' is the volume of the selected objects in cu" if the objects don't form a solid then it'll be a negative value...
Assuming that the user should have selected one group to get the volume...

if ss[0] and ss[0].class==Sketchup;;Group
  volume=ss[0].volume
  if volume==0
    UI.messagebox("Warning! The selected group has no volume")
  elsif volume<0
    UI.messagebox("Warning! The select is not a 'solid' group.")
  end#if
else
  UI.messagebox("Select ONE group!")
  return nil
end#if

there are many ways to achieve what you want