Please click the attachments to download a PDF containing the Aruco tracking markers. 45mm (60mm total) is the recommended size, but 22.5mm (30mm total) markers are also provided. Upscaling during plotting can be used to alter the size.
An A3 template is also provided for creating marker strips of 45mm markers with 7.5mm padding. These should be cut into 4 strips and assembled with consistent 7.5mm spacing.
Fologram currently supports 100 markers (0-99) of arbitrary sizes. The size can be overridden by specifying the printed size in Grasshopper. Multiple markers can be tracked at once.
A simple application that simply detects the marker location, draws a box on the marker and sends it back would be as follows:
Providing the size and IDs of the markers is optional, and only required when using different or mixed marker sizes.
The origin of the marker is in the center.
When using custom marker sizes not derived from the provided plot sheets, we recommend leaving a white border on all sides of at least 16.5% to improve detection rates. For example, on a 45mm marker a border of 7.5mm on all sides is desirable.
Printing with high contrast is desirable - when blacks or whites are dirty, marker detection rates may suffer.
It's important that the markers are flat, so printing on heavyweight paper or mounting to flat objects is desirable.
On some occasions, markers may be falsely detected. If you know the marker (or range of markers) that you are looking for in advance, you may wish to use the output IDs with a set index component to ensure that only the desired marker positions are used.
If you wish to use more than 100 markers, please let us know.
For more information about Aruco markers please see this article.