Diminishable visual markers on fabricated projection object for dynamic spatial augmented reality

This paper presents a novel visual markers for dynamic SAR, which are directly embedded on a 3D projection object printed out from a digital fabrication machine, in particular, full-color 3D printer. Since the markers are automatically embedded on a projection surface with mechanical accuracy, precise geometric registration is achieved(Figure 2). However, the shape of markers printed on a nonplanar surface is possibly deformed, which potentially decreases the performance of vision-based marker recognition. In addition, the marker itself is visually salient, and consequently, disturbs a user's sense of immersion. To solve the former issue, we apply a marker whose shape is topologically robust when being deformed. For the latter issue, we carefully decide the reflectance of the marker so that it can be visually diminished by projection while being detectable by cameras. We also proposed a novel marker placement method, which decides the positions of markers so that the position/pose of the object is accurately estimated from various viewpoints.