The ARPen application enables you to draw in mid-air.
By tracking a marker, lines can be created that keep their position in the real world.

Printing out a marker is all that is needed to test out this interaction. Or you can build a custom Bluetooth pen to have more options. The pen can be built using simple electronic components and machinery in your local Fab Lab. Detailed instructions are available at http://hci.ac/arpen-ios.

With this app you can:
- paint freehand in mid-air
- create simple geometry shapes like cubes
- create complex geometries using sweeps, lofts, revolutions, and merge&intersect operations
- explore techniques for moving, rotating, and scaling objects in mid-air
- explore different menu techniques
- explore depth visualization techniques to show the position of the pen tip relative to other objects in the scene
- export the sketch or model as an *.STL file

This application is part of the Personal Photonics project, which is funded by the German Federal Ministry of Education and Research (BMBF) as part of their Open Photonics call. For more information, visit https://hci.rwth-aachen.de/arpen