Note: This script is currently not working with Bullet in official trunk. Will be fixed in a couple of days.
And my recent post is still valid 
Script works now with official trunk r54095!
thanks again sergof and aligorith for integration of bullet.
I would love for someone to do a real detailed tutorial on your script Bashi, and constraints in general. I had a difficult time following what you were doing on the intro video, in part because my lack of knowledge on constraints, but also it was a little difficult to see because the video did not have any high quality viewing options. Maybe you can encode in 720p resolution on future ones. Thanks for your time in adding even more greatness to the new bullet physics integration.
i seeā¦ i might do a tutorial, or at least something more HDāy
I didnāt check the tutorial and only quickly tested it out, it works awesome!
I donāt know whether you should be able to create the constraints with the addon itself, since I was unable to do this. Instead I first create the constraints with bullet branchās own implementation and then selected all and used the refresh function to change the breakability etc 
*edit: to be more precise your addon creates the constrains yes, but they somehow just donāt work at all.
Thanks for creating this.
Test again with very latest Blender, there has been some changes past 1-2 Days about this behavior. should work now.
I downloaded r54076 win64 from builder yesterday. Is this too old?
Yes, was 54094
Ok itās now working fine with the newer version
Iām working with your constraint add-on in blender revision 54095, but it doesnāt seem to be workingā¦if I put the values at neighbor limit 2 and search radius 1 it works for about 3 minutes or so then it creates the empties but it also (at least I think what itās doing, I canāt use blender after itās done because itās too slow)adds constraints to the objects. heres a screenshot of my outliner:
Iām trying to add constraints to about 290 objects.
I will investigate. Are you using X Constraints, i guess?
Can you upload this file to pasteall.org? Best would be you tell me the steps to reproduce your Result. thanks
here it is:
http://www.pasteall.org/blend/19027
With the selected objects, I check constraint type, and breakable (both check boxes) and then press X constraints.
i canāt reproduce itā¦ iāve updated the addon today, so please re-download it and try again. should have said that beforeā¦
the left checkboxes are for enable the updating itself. So if you check āEnable Break threshold Updateā it does update the break setting on the right side. The checkbox āEnable breakable Constraintsā just right of it actually enables breaking of constraints. So you need to check 3 Checkboxes. but that should not have to do anything with the issue.
tell me when it still doesnāt work please.
YEAH! ITāS WORKING! HAHA!..sweet. 
Thanks man!
This looks super cool!
Super simple scene to test. A table and a ball falling but when I set constraints the table top falls in before the ball hits. I am using x constraints on build 54248 Win64bit build. Here is the file - http://www.pasteall.org/blend/19204 What am I missing? thanks!
Hi spatdsg, you have to less constraints there. try increase Neighbour limit and Search Radius. (try something like 5+5 on this scene)
Wow, this is really good! I canāt seem to find itās license anywhere, am I free to use this for commercial stuff?
Well, good question. Iāve used the KD-Tree Python implementation from http://code.google.com/p/python-kdtree/ which uses MIT license: http://opensource.org/licenses/mit-license.php
as far as i can tell, yes, you can use it/edit it for anything you want. Have fun.
Okay, thank you very much!