First up is Ricardo Sanchez, one of those guys who had been hindered by the lack of demos & documentation last year and has been in touch a few times about the physics engine. His questioning also directly triggered me to do a few more demos, which are now bundled with the last couple releases. A few days ago he excitedly told me that he’s finished his project and I wanted to share it with you here too:

You can download the Processing source code for this sketch from the project website and read some more about his process on his blog.

The other experiment I found is a nice showcase of the SphereConstraint in action to create a, well spherical, boundary for the physical simulation space. FYI the constraint can also be inverted and be configured to work as obstacle instead, not allowing any particles within the volume of the sphere. This can be achieved via a flag to its constructor.

The effect is quite interesting and somewhat reminds me of Mikkel Koser’s & shiftControl’s recent COP15 identity, although the behaviour of particles there is far more complex.

More detailed info about the most recent release and the behaviour changes it caused will be posted asap.

So over the holidays I’ve been doing some research about kinetic & mechanical art and then started working on some additions to various classes in the core and physics packages. These in turn needed testing and inspired me to create the little New Year’s greetings below:

Amongst other things the new additions include:

• ParticleString class to automatically connect a list of particles with springs or create a string of particles along a line/ray
• ParticlePath is extending Spline2D/3D and can turn the spline into a ParticleString sampled at an uniform interval
• New ParticleContstraint implementations and improvements to existing ones:
  • AxisConstraint locks movement of a single axis
  • PlaneConstraint locks movement in a plane (only 1 axis left to move in freely)
  • CylinderConstraint creates a cylindrical obstacle in the simulation space
  • BoxConstraint turns an axis-aligned box (AABB) into an obstacle
  • SoftBoxConstraint uses an AABB as perimeter and slowly forces particles towards its centroid coordinates (per axis)
• Reworked (corrected) velocity handling and accessors for contraints to manipulate particle velocities upon collision

Even though these updates are not yet part of a new release, you can download the source code (as complete Eclipse project incl. compiled versions of the pre-release libraries) and interactive realtime versions for OSX & Windows from here:

xmas.postspectacular.com/2010/

To get the project into Eclipse, simply use the Import wizard:

File > Import… > Existing projects into workspace > Next > Select archive file > Choose the downloaded zip > Finish

Apart from the showing how to use these new classes mentioned above, Processing heads might also be interested in the elegance of XML parsing using JAXB (one of my favourite additions to Java 6). Last but not least, the project is also utilizing the custom vector shape alphabet system originally developed for the onedotzero festival identity last year.

Happy 2010 everyone!