These are tensile-only members - capable of resisting extension, but not compression
Joints, hubs and connectors
These are membranes, capable of joining the gaps between struts
The simulation is performed in a virtual world with either
two or three spatial dimensions.
Forces simulated in Springie's universe include
compressive and tensile forces, electrostatic attraction and
repulsion, elastic collisions, gravity and friction.
Models of physical objects can be dynamically edited and
manipulated in this environment.
Persistence of Springie's models is performed using XML.
Springie allows import of models in a number of
formats. It reads:
An XML-based file format - Springie's native format;
"Elastic Interval Geometry" files - associated with SpringDance;
"Richard Buckminster Fuller" files - associated with Struck;
"Object File Format" files - as produced by Packinon and GeomView;
"Mathematica" files - associated with Mathematica and LiveGraphics3D details here;
"TView" files - by Bob Burkhardt - models are available [here] or [here];
.FABRIC files are associated with Fluidiom;
Support for importing other formats is planned.
Springie can also export models a range of formats:
.SPR files are an XML-based file format which is native to Springie.
.POV files are readable by the popular ray-tracing package, POV-Ray -
which can be used to generate high-quality still images of the models.
.WRL files (i.e. VRML model files) allows for higher quality
rendering than Springie offers natively - while still
allowing easy access to the models in an interactive 3D space
to users via a web browser.
.EIG (Elastic Interval Geometry) files are readable by the
program SpringDance - and some versions of Struck.
.OFF (Object File Format) files are readable by the programs in the
packinon project - and a number of other 3D model readers.
Support for exporting in other formats is planned.
Note that you will need to run Springie as an application
(rather than an applet) if you want to be able to read or
This limitation is due to security restrictions placed on
what unsigned applets can do.
To provide an illustration of the available rendering approaches,
here are some snapshots of Springie output:
Embedding models in web pages
There's a low-bandwidth version of Springie - known as SprView.
This runs as an applet and loads compressed model files from
archives over the internet.
SprView is intended for embedding tensegrity models in web