Selfmade targets allow for the flexibility which developers and researchers need for testing purposes. Upon request A.R.T. provides the corresponding material for passive and active targets, such as retroreflective foil or electronics.

If you want to build up your own targets, you have to apply only a few seemingly simple rules (the figures refer to tracking setups with at most 4m camera-target distance):

• A target consists of at least 4 markers in a fixed constellation.
• The minimum marker distance within a target should exceed 3cm.
• All distances of all markers in a target should differ by approx./at least  5mm.

But if you want to track more than one selfmade target in your setup, there are additional aspects you have to observe:

• The difficulty to create selfmade targets for one tracking setup increases with the number of targets, and
• a selfmade target may not work together with standard or future A.R.T. targets.

The marker distances within a target serve as a key to identify this target. More precisely, any subset of 4 markers and the corresponding marker distances a enough for identification. Now if a target contains a certain subset of markers, you have to avoid a similar constellation when constructing another target - else these two targets will not be correctly identified. This becomes a more and more complicated problem the more targets you want to use. And obviously, when constructing a new target, without knowing it you may run into a constellation of markers which is similar to one of the precalculated A.R.T. targets.

If you want to use your selfmade targets together with standard A.R.T. targets, we can help by checking for dangerous similarities between both target sets. But please note that currently we do not offer calculations to check for similarities within the set of your selfmade targets. If you need a large set of targets, you should better purchase our precalculated ones where the problem of similarity within a set does not occur.