[Plugin] Center of Gravity

Re: [Plugin] Center of Gravity

Postby TIG » Tue Dec 02, 2014 11:06 pm

When you say 'merged', do you mean that you have exploded the various parts into a single container and then ensured that the container is now a 'solid' ?
1
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby Nemesis » Wed Dec 03, 2014 2:29 pm

TIG wrote:When you say 'merged', do you mean that you have exploded the various parts into a single container and then ensured that the container is now a 'solid' ?

Under "merged" I meant - group all separate solids in one group, that was my mistake. Now, I made one solid from all parts and CoGs are now almost identical in both cases (separate solids and one big solid). Thank you for your patience.
0
User avatar
Nemesis 
 

Re: [Plugin] Center of Gravity

Postby sketchartist023 » Mon Jan 26, 2015 5:01 pm

Can you tell me what the accuracy % option does? I set to 100 and its quicker but sees less weight and at 1% takes forever but sees more weight. What should that be set at nominally for the most accurate readings? Thank you!!! Very great plugin, TIG :)
0
User avatar
sketchartist023 
 

Re: [Plugin] Center of Gravity

Postby TIG » Mon Jan 26, 2015 5:37 pm

The 'accuracy' setting affects the result... as you have found.
For simple forms the 'accuracy' of the results will not improve beyond a certain point, no matter what the settings are...
But otherwise the more 'iterations' the tool does the nearer the result is to being 'true'.
If you choose a 'more accurate' value, then the 'weight' might become more accurate, and the CofG might adjust very slightly.
If you have the time... then more iterations gives the most accurate results...
BUT sometimes the differences are so small it's not worth the delay...
It's up to you - your model - your time... :geek:
1
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby sketchartist023 » Tue Feb 24, 2015 5:05 pm

TIG wrote:The 'accuracy' setting affects the result... as you have found.
For simple forms the 'accuracy' of the results will not improve beyond a certain point, no matter what the settings are...
But otherwise the more 'iterations' the tool does the nearer the result is to being 'true'.
If you choose a 'more accurate' value, then the 'weight' might become more accurate, and the CofG might adjust very slightly.
If you have the time... then more iterations gives the most accurate results...
BUT sometimes the differences are so small it's not worth the delay...
It's up to you - your model - your time... :geek:



Thanks :) I found that using an accuracy of 5% works quite well with realtime weight on my end using the correct density I found on the internet for the material I use. Works a charm! Helps with configuring shipping information BEFORE having to go to Fedex etc and create real products beforehand so it reduces capital costs for me :) Thanks so much again. I have been within 5lbs accuracy with actual shipping items that I modeled. Just an update :)
0
User avatar
sketchartist023 
 

Re: [Plugin] Center of Gravity

Postby pazzamnik » Thu Apr 02, 2015 9:29 pm

Hey Tig,

Thanks for the CofG plugin. It has been working quite well, but have one small easy, which I think is easy to overcome. I have drawn an aluminum extrusion and set the aluminum density. The size of the extrusion is 1m in length, so I can know my run length cost/per linear meter.

Whether I extend the extrusion 1m to 20m in length, CofG always comes back and gives me the same weight? Yet if I copy the meter long extrusion, put a couple bends on it, and run CofG, it gives me a new and hopefully correct weight.

Wondering if there might b an issue with my group that is causing an issue?

Thanks.
0

pazzamnik 
 

Re: [Plugin] Center of Gravity

Postby Dave R » Sat Apr 04, 2015 2:18 pm

What method are you using to extend the extrusion? If you are just scaling the group or component, you aren't updating its definition. If you open the group/component for editing and then modify its length, the definition gets changed and the plugin should give you the results you are looking for.
0
Etaoin Shrdlu


%

(THERE'S NO PLACE LIKE)

G28 X0.0 Y0.0 Z0.0

M30

%
User avatar
Dave R 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby jojo9 » Wed Jun 17, 2015 11:21 am

Great plugin! its possible to add some toolbar buttons? i tried but had no luck.

Code: Select all
#--------- menu -----------------------------
unless file_loaded?(File.basename(__FILE__))
   txt0="C of G..."
   txt1="Find C of G"
   txt2="Composite C of G"
   dir=File.dirname(__FILE__)+"/TIGtools"
   toolname="CofGravity"
   locale=Sketchup.get_locale.upcase
   path=dir+"/"+toolname+locale+".lingvo"
   if File.exist?(path)
     txt0=deBabelizer(txt0,path)
     txt1=deBabelizer(txt1,path)
     txt2=deBabelizer(txt2,path)
   end#if
   submenu=UI.menu("Plugins").add_submenu(txt0)
   submenu.add_item(txt1){CofGravity.new(1)}
   submenu.add_item(txt2){CofGravity.new(2)}
   
=begin   
  #plus
    tb= UI.toolbar "Konstruktion"
    
   cmd = UI::Command.new(txt1) {CofGravity.calculate}
   cmd.small_icon = "../Images/Center_component_lg.png"
   cmd.tooltip = "Teilmassen Zentrum"
   tb.add_item(cmd)
   
   cmd1 = UI::Command.new(txt2) {CofGravity.composite}
   cmd1.small_icon = "../Images/Center_component_lg_sum.png"
   cmd1.tooltip = "Hauptmassen Zentrum"
   tb.add_item(cmd1)   
=end 
end#if
file_loaded(File.basename(__FILE__))
#---------------------------------
0
User avatar
jojo9 
 

Re: [Plugin] Center of Gravity

Postby TIG » Wed Jun 17, 2015 7:09 pm

tb = UI.toolbar.new("Konstruktion")
Makes the new toolbar.
And use: cmd.small_icon = "Images/Center_component_lg.png"
- assuming Images in in the same subfolder as the loading RB file ?
You cannot add a new button to a existing toolbar unless you have just made it, OR if the toolbar has been made during the same start-up session AND it has an enduring reference...
So in some earlier loading file [they load alphanumerically] use something like:
Code: Select all
module MY_STUFF
  ###
  TOOLBAR = UI.toolbar.new("Konstruktion")
  ###
end
Then in your second file: tb = MY_STUFF::TOOLBAR Which is an enduring reference to the 'MY_STUFF' toolbar entitled 'Konstruktion'...
You can then add buttons to that toolbar as SketchUp starts - in any later loading script...
1
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby jojo9 » Thu Jun 18, 2015 9:14 pm

TIG, thanks for helping! i got it running, with another loader script, as you said.
Furthermore, i corrected the call commands.
0
User avatar
jojo9 
 

Re: [Plugin] Center of Gravity

Postby Pockocmoc » Wed May 18, 2016 3:00 pm

Hi all, I am doing a 3D model in Sketchup 2016 and when trying to use CoG, it gives to me "weight=0.0"... How is it possible?

Here is how I do :
I create my 3D object, I select it and press "G" to save it as a single component. Then I select it, and I run CoG, applying a density of 7850 Kg/m3 (c40 steel density). It calculates during 5-6 minutes and finally shows 0.0 ...

Any idea?

Thanks!
0
User avatar
Pockocmoc 
 

Re: [Plugin] Center of Gravity

Postby TIG » Wed May 18, 2016 3:44 pm

Is it a 'Solid' object in Entity Info ?

Without seeing the actual object and the settings you used I can't say what the issue might be.
0
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby Pockocmoc » Thu May 19, 2016 9:17 am

Hi :) !

Well, it seems it is not recognized as a solid, because there is no "volume" entry in the Entity Info box.

Here is a picture :


Thank you.

Pock'
0
User avatar
Pockocmoc 
 

Re: [Plugin] Center of Gravity

Postby Pockocmoc » Thu May 19, 2016 9:52 am

Oh, and even with a simple cube, (wich is solid) it does the same : no weight...
0
User avatar
Pockocmoc 
 

Re: [Plugin] Center of Gravity

Postby TIG » Thu May 19, 2016 12:17 pm

What version do you have ?
It should be v1.7 from the SketchUcation PluginStore ?
It's 3 years old but works on newer SketchUps anyway...

If you run it with the Ruby Console open are there any error messages ?

What settings are you using ?

What is getting reported exactly ?

Obviously the object's size versus the chosen density units can cause small objects to be reported as 0...
A small 'blade' probably needs to be in g/cm³ or similar...

Here's what I get with a component cube with protruding numerals [v2016].
It's a but over 1 m³ with a density of 2000 kg/m³ at the default 1% accuracy setting it returns a true volume in m³ and a weight in kg...
A much smaller [scaled] version reports '0' when the overly large units misapplied, but with g/cm³ it's fine...

Can you post a simple SKP that has issues so I can test it...
0
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby Box » Thu May 19, 2016 1:16 pm

It sounds like you may be creating component, but failing to tick the box that replaces the raw geometry with the component.
If there is no bounding box around your object it is just raw geometry, see if the component is in the component browser for you ready to use.
0
User avatar
Box 
 

Re: [Plugin] Center of Gravity

Postby Pockocmoc » Thu May 19, 2016 2:29 pm

I am so stupid :roll: ... you are right TIG, it was because of the units, obviously! The blade weights 42 grams, so (0.0)42 Kg .



Thank you for all.
0
User avatar
Pockocmoc 
 

Re: [Plugin] Center of Gravity

Postby hute_zhaw » Mon Mar 13, 2017 5:06 pm

Hi Folks

I just installed this plugin into SketchUp 2017. It doesn't work as expected for me. The find CofG still works fine as far as I can tell but the Composit CofG returns a ruby error:

Code: Select all
Error: #<TypeError: reference to deleted Group>
/Users/hute/Library/Application Support/SketchUp 2017/SketchUp/Plugins/CofGravity.rb:670:in `entities'
/Users/hute/Library/Application Support/SketchUp 2017/SketchUp/Plugins/CofGravity.rb:670:in `block in do_composite'
/Users/hute/Library/Application Support/SketchUp 2017/SketchUp/Plugins/CofGravity.rb:669:in `each'
/Users/hute/Library/Application Support/SketchUp 2017/SketchUp/Plugins/CofGravity.rb:669:in `do_composite'
/Users/hute/Library/Application Support/SketchUp 2017/SketchUp/Plugins/CofGravity.rb:117:in `initialize'
/Users/hute/Library/Application Support/SketchUp 2017/SketchUp/Plugins/CofGravity.rb:817:in `new'
/Users/hute/Library/Application Support/SketchUp 2017/SketchUp/Plugins/CofGravity.rb:817:in `block in <top (required)>'
SketchUp:1:in `call'


Has anybody got a clue how to fix this? It is really a pretty cool plugin and would be a shame if it became unusable.
0

hute_zhaw 
 

Re: [Plugin] Center of Gravity

Postby TIG » Tue Mar 14, 2017 12:36 pm

Thanks for the bug-report.
I suspect that this is a glitch in the way v2017 handles exploded entities.
I'll investigate and fix it...
0
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby TIG » Tue Mar 14, 2017 1:12 pm

Here's v2.0

Download

Its coding is now compatible with v2017 and it is also signed for use in v2016/v2017 in any loading-policy.
1
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby hute_zhaw » Mon Mar 20, 2017 11:01 am

Outstanding work TIG, thanks that was quick, I can confirm it works after the upgrade of the plug-in.

Cheers
0

hute_zhaw 
 

Re: [Plugin] Center of Gravity

Postby jbkbm » Fri Aug 04, 2017 6:19 pm

The plugin does not seem to be able to detect hollow spaces. Am I doing something wrong? I am trying to find the CoG of steel assemblies but when it calculates the weight, it includes the space between plates and gives me a number much higher than the actual weight.
1

jbkbm 
 

Re: [Plugin] Center of Gravity

Postby TIG » Fri Aug 04, 2017 8:45 pm

Your image attachment isn't showing.
An object needs to be a sensibly formed 'solid' - as reported in Entity Info.
Otherwise results can be flaky...
'Hollows' are accounted for, if it's a proper solid...

If you attach your SKP we can look at it...
0
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby lsorrentino » Mon Aug 21, 2017 4:17 pm

Hello All, hello TIG,
I want to calculate the center of gravity of a small magnet, but the calculation always report volume = 0 and eventully weight = 0.

The plugin works perfectly on my pc with larger objects, the density is 7.6 g/cm3, I'm a newbie with sketchup in general, I'm probably doing something wrong :(

Luca
0

lsorrentino 
 

Re: [Plugin] Center of Gravity

Postby TIG » Mon Aug 21, 2017 8:02 pm

It must be a rounding issue.
The object looks like it has no volume to SketchUp, therefore no weight.

I'll investigate...
0
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby TIG » Mon Aug 21, 2017 8:16 pm

Yes, I see it.
It was never intended for such small objects.
It rounds to the nearest cu", so your small object appears to have no volume !
I'll look at a way of adjusting it...
0
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby lsorrentino » Mon Aug 21, 2017 8:25 pm

Wow, very interesting. Thank you very much!
0

lsorrentino 
 

Re: [Plugin] Center of Gravity

Postby TIG » Mon Aug 21, 2017 8:41 pm

Here's v3.0

Download

It now reports the Volume/Weight of very small objects with more dp etc...
0
TIG
User avatar
TIG 
Global Moderator
 

Re: [Plugin] Center of Gravity

Postby lsorrentino » Mon Aug 21, 2017 10:21 pm

Thank you very much, I will use it tomorrow!

Luca
0

lsorrentino 
 

Re: [Plugin] Center of Gravity

Postby lsorrentino » Tue Aug 22, 2017 8:35 am

It obviously works!!!

Thank you very much TIG, extremely useful plugin.

Luca
0

lsorrentino 
 

SketchUcation One-Liner Adverts

by Ad Machine » 5 minutes ago



Ad Machine 
Robot
 

PreviousNext


 

Return to Plugins

Who is online

Users browsing this forum: No registered users and 19 guests

Visit our sponsors: