A Tangible Augmented Reality System for Object Configuration

The tangible augmented reality system for object configuration (TAROC) provides tangible elements which can be combined to a physical model. Based on this model’s composition, a digital counterpart is computed in real-time and rendered onto it in augmented reality (AR). Thereby, each of the undetailed tangibles represents a specific part of the target object, such that different combinations lead to different detailed, virtual prototypes. TAROC combines embedded computation with visual marker tracking to enable robust and accurate real-time tracking. Using microprocessors inside the tangibles, the composition of the model can be determined independently of the blocks being visible to the tracking device. Furthermore, fiducial markers are used to track an element’s spatial information, such that the computed visual model can be attached to the physical one in real-time. One of the core features of a configuration tool is the possibility to individualize different properties of the configured item. Next to the composition tangible augmented reality (TAR) interface, a further marker-based TAR interface enables users to choose between different attribute values. These interfaces provide visual as well as haptic feedback to the user, leading to a more realistic configuration experience. In this work, the given approach is presented in detail and important design decisions are explained. A sofa configuration tool is shown as a practical implementation and is used to figure out advantages and disadvantages of this concept. Users can combine tangible representatives of a single-seater, corner pieces, a two-seater and a chaise longue. Furthermore, the base type, the color and the texture of their sofa can be manipulated using configuration wheels. These wheels are divided into three parts, each representing another value of the corresponding attribute. Depending on a wheels rotation, a value is chosen and the visual model of the sofa updates in real-time. Next to each part of a wheel, a tangible representation of the attribute value can be seen and touched. Thereby, a user will receive realistic visual and haptic feedback, improving the user experience. To justify the combination of embedded computation and marker tracking, a technical evaluation is documented. Thereby, two scenarios occurring in user interactions are simulated and a comparison between the given approach and an application based on marker tracking only is drawn. In the first scenario, markers are being occluded and thus not visible to the tracking device. While the marker-only-based application needs to detect one fiducial marker on each element to render the full model, it is sufficient to track one marker in total for TAROC. The second scenario addresses perspective distortions, which appear if a user rotates connected cubes. As one marker being visible to the tracking device is sufficient for TAROC, the visual model stays in place and rotates correctly with the physical model. In contrast, the marker-only-based application loses track of the perspectively distorted markers at a rotation of 50 degrees or higher, leading to the corresponding visual counterpart not being rendered.