Occlusion handling method for ubiquitous augmented reality using reality capture technology and GLSL

The primary challenge in generating convincing Augmented Reality (AR) graphics is to project 3D models onto a user's view of the real world and create a temporal and spatial sustained illusion that the virtual and real objects co-exist. Regardless of the spatial relationship between the real and virtual objects, traditional AR graphical engines break the illusion of co-existence by displaying the real world merely as a background, and superimposing virtual objects on the foreground. This research proposes a robust depth sensing and frame buffer algorithm for handling occlusion problems in ubiquitous AR applications. A high-accuracy Time-of-flight (TOF) camera is used to capture the depth map of the real-world in real time. The distance information is processed using the OpenGL Shading Language (GLSL) and rendered into the graphics depth buffer, allowing accurate depth resolution and hidden surface removal in composite AR scenes. The designed algorithm is validated in several indoor and outdoor experiments using the SMART AR framework.