Just wanted to share this PDF we made.
It contains id 0 Fiducial is ever decreasing sizes. They start with a large one at about 10cm and scale down in increments of 90% until the smallest one which is about 1cm. 20 different sizes are present on the sheet.
When building multitouch devices, it is often hard to guess which size of fiducial you will need to use based on acrylic thickness, location of projection surface, distance to the camera, edge effects like warping due to lenses, etc…
Print this sheet and place it on the surface of your multitouch device. All of the fiducial on the sheet are id #0 from the standard reactvision set so no custom trees needed.
Measure the smallest fiducial which can be resolved to an ID by your tracking software everywhere on the surface and there you have it! The correct size of fiducial which matches your setup.
Edit: Forgot to mention. This sheet is cross platform. If you print it out it works on Windows, OSX and Linux