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Bullet Physics Contest: Best Rube Goldberg Device wins a PS3 / Wii


mousetrap_30.jpgErwin Coumans, developer of the Blender game engine and the Bullet physics library, Bullet, does it again: he is offering an impressive prize for the creation of the coolest Bullet demo. With his previous contest you could win a PSP but this time the ante is upped: you can win a PS3 or a Wii.

This time the goal is to create a fun-to-watch simulation in Rube Goldberg-style, in which you had to create needlessly complex and weird contraptions to achieve a simple goal. Check out for Rube Goldberg's original comics, and the Wikipedia page on his work.

For a good Blender example of such a contraption check out fobsta's 'Mousetrap' on BlenderArtists. There's also a video of this scene available from YouTube. Pretty cool stuff.

This contest will require you to make good use of the new Bullet functionality that he has been steadily adding such as compound shapes and GUI for editing rigidbody constraints (ragdolls, hinges etc) and Mac OS X mouse-look. (More physics features for animation purposes (ragdolls etc) with more GUI are planned for Blender 2.44 and later in 2007). To make sure it is just a Rube Goldberg simulation and not a puzzle game, it is not allowed to have a 'puzzle-building region' in the entries.
The contest ends 1 March 2007. For more information, please visit the Bullet Physics Contest Homepage.

Update: by Erwin's request, we've slightly changed this article.

About the Author

Avatar image for Bart Veldhuizen
Bart Veldhuizen

I have a LONG history with Blender - I wrote some of the earliest Blender tutorials, worked for Not a Number and helped run the crowdfunding campaign that open sourced Blender (the first one on the internet!). I founded BlenderNation in 2006 and have been editing it every single day since then ;-) I also run the Blender Artists forum and I'm Head of Community at Sketchfab.


  1. Oh! I copied that straight from the email Erwin sent to me about his contest. @Erwin: maybe you can comment on this? Can people use the mouselook for the contest, or not?

  2. They can probably use it, i don't think it would be required was what i was tying to say. Mouselook is a generic GE feature but not physics related.


  3. This contest is one of the most awesome (and i don't say that word often) thing I've seen in a long time. Ever since the development of "The penguin machine" has halted because of fear of patent problems (see the comments) i never expected something similar to pop up again ... here's hope one of the entries for this contests will manage that ;)


  4. Holy crap... Here we go again.. If we're going to do this, would it be too much to ask for better timing? Problems with the clock on ati cards will make orchestrating a fluid camera to follow the scene difficult.

  5. Mousetrap is a board game. I know because I have it.

    I saw this, and I was going to try to recreate "Mousetrap," myself, but I see that's already been done. Hm...

  6. For more background on this sort of contraption see . It'll be interesting to see how the physics engine will react to stuff like this. Rube Goldberg machines in real life are testy, much less a virtual one. But hey, what better way to test the physics engine? For another example, the Christmas epsisode for the show MythBusters involved a Rube Goldberg machine.

  7. There will be a special section in the Wiki, similar to the previous PSP contest. So contestants can just edit their own entry, until the deadline (1st march) is reached.

    This wiki page/registration will be available 'when its done' or 'really soon', and its link will be added here:

    Don't forget to try out the latest Blender 2.43 preview and physics demos, they might provide a good starting point:

    Enjoy and please create some fun machineries!

  8. This looks like a contest for me! Marty, Those are the coolest videos! Thats definetly good inspiration.

    in the .blend file for fobsta's "mousetrap", the ball seems to move way to slow. Is there a way to speed up the engine?

  9. This is not a speed issue, the scaling of the objects is way too large: 20 ~ 40 meters/units.

    It will be fixed, but the mousetrap/movie is just a quick example to give some direction.

  10. Hi. I have downloaded an example which Appolonius made and gave link at continousphisics forum. the machine havent worked properly, when sphere should puch domino, sphere dont touch domino.

    And this is the problem - machine which works on someones computer, can not work on faster/slowler computer, when next move depends only of touch of other object, this obj can not touch other on other computer.

    So how about it? Maybe recording the movement? Of course blends must be send.

    How about using python?

    Big machines can be build of many dynamic objects, so can machine be done in more then one scene, whcih will change after each part?

  11. The .blend files might not work the same on all platforms/Blender builds, but CPU speed shouldn't matter.
    Linux, Windows, Mac OS X all might have slightly different optimizations which impact the overall behaviour.
    With more experience you can improve the reliability of the movement.

    You can bake IPO's or generate a movie if you like, but indeed a .blend or other method to re-create should be provided (including the platform used).

    Yes, you can do whatever you like, you can use python, and you can also use multiple scenes.

    Good luck!

  12. Brilliant stuff!!

    Incredible Machine brings back sooo many interesting memories. I loved that game, and was looking for something similar, but never thought of building one with Blender. I'm going to definitely give this one a go.

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