Addressing the Occlusion Problem in Augmented Reality Environments with Phantom Hollow Objects

Occlusion handling is essential to provide a seamless integration of virtual and real objects in AR applications. Different approaches have been presented with a variety of technologies; environment conditions and methods. Among these methods; 3D model-based occlusion approaches have been extensively used. However; these solutions could be too time-consuming in certain situations; since they must render all the occlusion objects even though they are invisible. For this reason; we propose an inverse 3D model-based solution for handling occlusions; designed for those AR applications in which virtual objects are placed inside a real opaque object with holes or windows. With this restriction; the occlusion problem could be solved by rendering the geometry of transparent/hollow objects instead of rendering the opaque geometry. The method has been tested in a real case study with an augmented car in which the virtual content is shown in the interior of the vehicle. Results show that our method outperforms the traditional method; proving that this approach is an efficient option for solving the occlusion problem in certain AR applications.