Physion: create your own virtual physical world


Imagine that you could create any object you want by the flick of a mouse, many different kinds of objects, in fact, of various shapes, colors, and  properties, and that you could then watch these objects interact with each other and the virtual world around them exactly as you would expect them to interact in the physical world.

This, in a nutshell, is what this software will let you do.

Physion is a free 2D Physics simulation software. It can be used to easily create a wide range of interactive physics simulations and educational experiments.

Teachers may find it particularly useful since it can be used as a virtual physics laboratory through which they can demonstrate basic physics concepts in the classroom.

Physion may also be useful to game developers since they can use it as simple level editor for their platform games.

Physion Screenshot

Physion Screenshot2Physion is not unlike previously mentioned Phun Physics, in that it lets you create your very own world of objects and relationships. Object creation is simplicity itself; you simply select the object from a toolbar (circles, rectangles, polygons, gears, chains, ropes, balloons and lots of other items), place it where you want it in your two-dimensional environment, and use the mouse to define it’s size. You can also connect those items using springs, pulleys, nails and other types of joints.

Beyond object creation, the user can change the properties of objects, such as friction, restitution, density etc. in real time (shift+p will display the properties dialog). Moreover, the properties of the environment itself can be altered (shift+s), allowing you for example to create world where gravity is much weaker or stronger, etc. Events, such as for example (if the red ball collides with this wall then smash into several dozen pieces) can be scripted as well.

Once you are done creating your scenario, you can press the “play” button, much as you would on a media player, to see the “outcome” and interactions in the world you’ve created.

Here are some pros and cons for this software:


  • Presents a wide range of possibilities: limited only by your imagination. (The developer mentions, for example, its potential usefulness as a level editor/creator for platform games).
  • (Relatively) small learning curve: the interface is simple and straightforward, and all you need to do, after playing with it for a while, is go to the help section, which will usher you to many different tutorial videos on YouTube.
  • Comes with lots of community based examples: that can be loaded up from a central repository and viewed. You can download more that are available online or even upload and share your own creations.
  • Events can be scripted: Physion supports scripting with Javascript. This means that the users can write their own scripts and execute them through Physion’s scripting engine. Most of the actions that can be performed through the graphical user interface have their equivalent javascript commands. This way Physion can also act as a fun and friendly platform for introduction to basic programming concepts.


  • Can at times be buggy: not more so than the average program, perhaps, but it did crash on me a couple of times during the course of testing. Note, though, that I was using it on a virtual machine.
  • There is probably no avoiding scripting: that is, if you want to be serious about harnessing the power of what Physion can do. This, at least, is how I see it, and is not necessarily a negative point. You can chalk the fact that this is in the “cons” section to this writer’s “coder’s envy” Winking smile

The verdict: In a world where physics based games on computers and smartphones are grossing millions, this is excellent free software that can provide fertile ground for your imagination and creativity, and a scratchpad to experiment with ideas.  Kudos to the developer for software that is very well put together (and for putting it out for free!).

See this software in action below:

Version Tested: 1.01

Compatibility: Windows and Linux (32 and 64bit).

Go to the program home page to download the latest version (approx 16 megs).

  • chris

    Very cool thanx!

  • Hi Gizmo

    Thanks for all the incredible tips, tricks, fun and information.

    I thought you might like to know something I just learned while searching for a “Phun Download”

    Apparently Phun was the open beta testing version of Algodoo and as such Phun is no longer promoted, developed or supported.

    As far as I can tell Algodoo is only available commercially. I might be wrong but here’s the web address:

    And this is the last Phun Website which hasn’t had an update to it since February 17 2009:

    When you click on the “Download Phun” button you end up at:

    So I’m sorry to say but your Phun info is out of date and although there’s still a universe of fun still to be had there’s not a whole lot of PPhun to be had anymorem

    Thank Goodness for Free New, Clear Physion (Just Phunning around with Punning) that you found.

    Thanks again and all the best to you


    • Samer

      @ Starlight: thanks for the info. I probably have a last freeware version of Phun somewhere and will put that up in the Phun posting.

      PS. I’m not Gizmo; you’re probably thinking of Gizmos freeware, a great freeware site.

  • Yes very nice physics program. Just added it to my list.

  • Try this:

    You won’t be disappointed. 😉