Bullet Constraints Tools


[vimeo 56245713 w=400 h=300]

Addon for creating Constraints for Blender 2.66

download Bullet Constraints Tools 0.3.7


I implemented a KDTree to make X-Constraints, means multiple Constraints per Object. (Atm it does only compare Object Pivot/Center)

There should be as well a Visual Feedback System. I have to check with Sergof (probably) if there are some Plans for Visualize Constraint in the Viewport. That’s the one thing, beeing able to see Constraints. Ideally the Tools should be more Interactive/Instant Visual Feedback, like show where Constrains are gone be built. Might be possible with OpenGL.

Together with the Feedback, there are some ideas for the Grease Pencil. Atm it uses only Point location of Stroke, but there are way more possibilities.. Use distance from Stroke to Influence, for Example Break Threshold/Friction. Or use Colors to determine Strong and Weak Constraints? But how does it get mapped, and how can you set it up? For this i need some Feedback. I’d like to keep it as simple and powerful as possible.

It could be as well possible to have Object Groups?  Not sure about this, somehow the selection approach is pretty straight forward…

Having spent a couple of Days now with this Tool, and the Idea behind it: You could possibly extend a Constraints Generator like insane, but it get’s very fast very complicated, thinking about all the Ways of how a Scene/Objects could be analyzed together with what is the best way to intuitively set Up Constraints. The Grease Pencil, actually more of a “oh yeah, that could be fun, let’s try” thing kind of demonstrates this. The moment i realized that you can draw Constraints inside a Object.. Think about 😉

What i would need know from you is some Feedback. Is the Tool usable at all? What do you miss? What is complete BS? What would you like to see?

I hope you have some fun with it. I certainly had, the last couple of days 😉


Add Enable Deactivation/Start Deactivated and Linear/Angular Velocity


Fix GPencil

Update 0.3.7

Ground Connect uses KD-Tree. Faster.

Update 0.3.5

X Constraints now makes only 1 Constraint per 2 Objects (Double Avoid).

GPencil Mode, separated GPencil Distance from Search Radius

Added Constraint Limits & Springs.

Empty Constraints Type now different Appearance for different Constraints.

Option only gets updated if Checkbox left is activated.

Update 0.3.3
GPencil uses KD-Tree now. Delete Constraints works much faster too.

Update 0.3.2
Implemented KD-Tree


The Tool is mostly selection based.

X Constraints

  • Generate multiple Constraints between Objects. (Atm it does compare Object Pivot/Center)

Neigbour Limit

  • Max Number of Constraints for X-Constraints

Search Radius

  • Max Distance Objects can have to still make Constraint between.

Generate Constraints

  • Make Simple Constraints between Objects

GPencil Mode

  • Disabled =  Edit constraints, Enabled = Edit and Generate Constraints


  • Allows to Draw/Edit Constraints with Grease Pencil Strokes.
  • Can be used to draw Ropes (See Video)

Distance for GPencil

  • Set distance for GPencil to take effect

Constraint Selected 2 Active

  • Connects all the selected Object to the Active Object.

Collision Margin

  • Collsion Margin


  • Friction of Objects

Enable Deactivation/Start Deactivated

  • Update Rigid Body Dynamics


  • Enables Breakable for Constraints

Break Threshold

  • Force needed to break Constraint. Like Strength/Integrity. The Value for each Object gets calculated by it’s Mass, so:
  • Object Break Threshold = Object Mass * Bullet Tool Break Threshold (The Reason for this is simple, heavy Objects need stronger Constraints)


  •  In some cases you might want to set Absolute Break Threshold Values. This will skip Mass from calculation so:
  • Object Break Threshold = Bullet Tool Break Threshold


  • In some cases you might want to make a Setup of different Constraints (different Break Values!) or edit Objects with different Break Values. So:
  • Object Break Threshold = Object Break Threshold * Bullet Tool Break Threshold

Ground Connect

  • Connects selected Objects to active Object Vertices (usually Ground). Currently it uses the active Objects vertices, so you need some Vertices there in order to it to work. This feature is, like anything else, not yet finished.

Remove Constraints

  • Removes all Constraints on selected Objects. (includes Empties made from Ground Connect)

15 responses to “Bullet Constraints Tools

  1. Pingback: Fracturing Wood | Blender HD·

  2. Pingback: Blender 3D Tutorial – Rigid Body Constraints Tools Addon | BlenderHilfe.de·

  3. Fantastic! Just what I’ve been looking for! I’m writing some tests to use the Vertex Weight Proximity modifier to determine when to generate constraints and how strong the breaking component should be (some kind of surface area calculation + mass + user input). It will probably be slow, but will work better in the scenarios I want (rather than object centers).

  4. The breakable constraints are not working using the latest addon with blender 2.66a and 2.67. I downloaded the latest addon (dated July 5th 2013). If the addon works fine with those versions of blender, may you please upload a .blend project that uses breakable constraints? I would be more glad if you can send us the steps how to create them to know our faults. Thank you so much for your great effort

  5. this is a good tool! i was confused on how to install it to blender. but now i know how to. i just told my brother about it! tomorrow, i’ll play around with it, and maybe i will get something… and thanks for the bullet constraint tools!

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