Authoring 3D virtual objects with tracking based input in augmented reality on mobile Devices

Abstract

The vastly increasing computing power combined with the camera, touchscreen, and a wide variety of sensors make smartphones and tablets a perfect platform for Augmented Reality (AR). Current AR applications are targeted at displaying interactive virtual objects, but do not provide the interface for creating or editing them. This project examined the feasibility and usability of using a mobile device for creating virtual 3D models in AR itself.

In this project the user input is provided by tracking the position of colored markers. Interpreting the tracking based input proved to be challenging because of a lack of state information, imprecise depth tracking and (partial) occlusion of the markers. These problems were addressed during this project. The concept of the virtual grid was introduced to guide the user input and ease the drawing process.

An early feasibility study proved the feasibility of constructing simple 3D objects in augmented reality using a 3D tracking input device. Participants liked the concept of using a tracked marker, but had troubles using it. As a result the prototype was altered to address these issues.

A more formal evaluation was held to evaluate both the improved concepts and to get a better understanding of the influence of the virtual grid. During this evaluation, the results used to determine the usability improved from bad towards very positive when the virtual grid was used. The ratings of the drawings created with the virtual grid are between 'Good' and 'Very Good', while this was not the case when the virtual grid was not functional.

Both a tablet and a smartphone proved to be suitable devices for an AR drawing application. The differences between the devices were small and mostly not significant. The trend is that a smartphone scores slightly better in terms of ergonomics while a tablet provides a slightly better usability.