Android AR / marker as anchor / drawing obj?

hello, instead of hitting the phones screen with my finger to create an anchor and draw an obj (like in Andres Colubri´s nice AR tutorial) i would like to place it automatically when/where an optical marker is detected (e.g. printed image on the real world floor). are there any tutorials or leads i could follow? the web seems a bit shy about this. opencv, ketaicamera, nyartool combinations do something in this direction but not in processings android AR mode with drawing and viewing an obj file in augmented reality just with your android device, right?