[Plugin] Center of Gravity

TIG

Hm. This is a very interesting piece of plugin, TIG; thanks!
It immediately brings teaching into my mind - as how you can (for instance) explain the different vectors arising in a Gothic structure for instance. It would be (also) interesting to see how these centers of gravity can interact with each other after a structure is assembled.

It came from a PM request for a tool to find the perfect lifting point for a delicate piece of restoration stonework...
I added the composite tool to combine the CoG's and SP's of assembles of multiple or varying density units...
Any more ideas welcome...

TIG

'Composite C of G' is for use only on existing C of G elements - it's used to get a combined C of G for them.
If you have an assembly of parts that all have the same density then you can just make one group of all of them and find the C of G of that one group.
BUT if you have an assembly of parts of different densities you'll need to find the individual C of G's of each of them: then you select these C of G elements [only these, nothing else] and use the Composite C of G tool on them.
You only need to use the Composite C of G tool on the C of G's of parts with different densities that could unexpectedly relocate the assembly's C of G - 'off center' for example... Otherwise group and get the one C of G...

pilou

No problem i can make the Xray mode by hands

Another thing
Seems "Composite mode" don't works for me

object goup 1(without CoF), object goup 2(without CoF),
group 3 = Group1 + Group 2
Find Cof for group3 ok

object goup 1(with CoF), object goup 2(with CoF)
group 3 = Group1 + Group 2
Composite group 3 not Ok
What I miss?

pilou

@unknownuser said:

with different densities

haaaaaaaa
THX!

chrisjk

I can't seem to get it to do anything on a Mac..

TIG

@chrisjk said:

I can't seem to get it to do anything on a Mac..

Please explain a little more...
What can't you get to work ?
Open the Window > Ruby Console.
Select a group or component instance that has a volume - we are trying to find it's C of G !
Run the tool and answer the dialog's questions...
What happens / doesn't happen ?
What are the messages if any in the Ruby Console...
There is nothing different between a PC and a Mac for this tool [except 'PEBCAK' ]

driven

Error: #<NoMethodError: undefined method db' for CofGravity:Class> /Library/Application Support/Google SketchUp 7/SketchUp/Plugins/CofGravity.rb:153:in calculate'
/Library/Application Support/Google SketchUp 7/SketchUp/Plugins/CofGravity.rb:813

Dave R

I just installed it on my MacBook and tried running it. It worked fine for me. Thank you TIG.

TIG

@driven said:

Error: #<NoMethodError: undefined method db' for CofGravity:Class> /Library/Application Support/Google SketchUp 7/SketchUp/Plugins/CofGravity.rb:153:in calculate'
/Library/Application Support/Google SketchUp 7/SketchUp/Plugins/CofGravity.rb:813

Have you got deBabelizer.rb in the Plugins Folder ?
This file is for translation and is used by many of my tools and it ships with each of them - although it's always the same file...
It should come with the zip and is installed into the same folder as CofGravity.rb ?
The error is because 'db' which is the local def of deBableizer in the class is failing to get defined...

driven

@tig said:

Have you got deBabelizer.rb in the Plugins Folder ? :?

Hi Tig,

I only installed it to send you a report from another Mac, and am sure I used all of the correct instal procedures.

your other tools are still working (EEby.., Manifold, Vol..2) , after the CofG_1.2 instal (including deBalelizer.rb)

after the first (_1.2) Error, I replaced both files with the _1.1 files and had the same error.

I then tested all in the same drawing
EEby Rail--worked
Volume2 --worked
Manifold --worked
CofG --same error report (-1.2 re-installed from zip)

john

TIG

driven

A mystery...


def CofGravity;;calculate ### LINE 129 ==start of class/def that is reporting the error...

def db(string)
  dir=File.dirname(__FILE__)+"/TIGtools"
  toolname="CofGravity" 
  locale=Sketchup.get_locale.upcase
  path=dir+"/"+toolname+locale+".lingvo"
  if not File.exist?(path)
    return string
  else
    deBabelizer(string,path)
  end 
end#db

if (Sketchup.version.split(".")[0].to_i<5)
     UI.messagebox(db("C of G; Sorry, this is Version >= 6 Tool !"))
     return nil
end#if

model=Sketchup.active_model
entities=model.active_entities

############
if Sketchup.version[0,1].to_i > 6
  model.start_operation((db("C of G")),true)### LINE 153 GIVES ERROR !!!

Can you look at the script's contents and see if it looks like this ?
Works fine on a PC for me - can't see where a Mac might trip up ?

Jim

Need to require 'dBabelizer' before you use it.

TIG

Jim

That's it ! Thanks.

Other tools requiring it were masking the fact I missed it out of the initial 'require'...

Update on it's way !!!

driven

that appears exactly the same,
the only thing that seems at odds is the syntax colouring for calculate shows it as a variable??
I don't know enough to know why, or where to look next

this is odd...

I'll send this even if the missing "require" is at fault, because I don't understand why one and not the other would be a variable....

TIG

Here's v1.3...
http://forums.sketchucation.com/viewtopic.php?p=229404#p229404
The initial 'require' of deBabelizer was accidentally missed out, but its absence was masked by some other tools loading it anyway so most times it worked anyway...
Now it is explicitly called for in the tool...
Sorry for the confusion...

driven

Same error code, same syntax colouring for line 813

seems to have something to do with it...

TIG

driven

Have you got the recent v1.3, with the require 'deBabelizer.rb' added ?
This should fix it ?

TIG

If calculate is a reserved term in Mac Ruby versus PC I'm surprised...
You can edit the file and change every ' calculate' to say ' do_calculation' and see if that helps - if so let me know asap

driven

Yes it's v1.3

changed to tig_calculate (lines 131, 815)

Error; #<NoMethodError; undefined method `db' for CofGravity;Class>
/Library/Application Support/Google SketchUp 7/SketchUp/Plugins/CofGravity.rb;155;in `calculate'
/Library/Application Support/Google SketchUp 7/SketchUp/Plugins/CofGravity.rb;815

but the colour changed

TIG

@driven said:

Yes it's v1.3
changed to tig_calculate (lines 131, 815)

Error; #<NoMethodError; undefined method `db' for CofGravity;Class>
> /Library/Application Support/Google SketchUp 7/SketchUp/Plugins/CofGravity.rb;155;in `calculate'
> /Library/Application Support/Google SketchUp 7/SketchUp/Plugins/CofGravity.rb;815

You mustn't have changed them all as it's still calling 'calculate' ?
I've redone the original and v1.4 with full 'do_calculation' will be there asap...