Eurographics Symposium on Virtual Environments (2006) Roger Hubbold and Ming Lin (Editors) A multi modal table-top 3D modeling tool in augmented environments Tom Novotny 1 , Irma Lindt 2 and Wolfgang Broll 2 1 Media Cologne, Hürth, Germany 2 Fraunhofer FIT, Sankt Augustin, Germany Abstract Even with today’s highly sophisticated 3D modeling programs, creating, assembling and adapting 3D models is still a big challenge for inexperienced users. In this paper we present our approach of an intuitive table-top 3D modeling tool in Augmented Reality. It allows the author to view 3D virtual objects within his natural working environment, to manipulate them and to create new 3D elements easily. The offered interaction techniques support the author’s activity by a combination of tangible user interfaces with voice recognition, a gaze-based view pointer and 3D widgets as components of a multi modal user interface. Within the scope of this work, intuitive interaction techniques were realized to offer the participants an easy way of working within an augmented environment. User tests were performed to compare our approach to a WIMP-based desktop application and to an alternative AR modeling application. Categories and Subject Descriptors (according to ACM CCS): H.5.1 [Multimedia Information Systems]: Artificial, augmented, and virtual realities H.5.2 [User Interfaces]: Evaluation/methodology, Graphical user interfaces (GUI), Input devices and strategies 1. Introduction 3D models are essential for many application areas includ- ing movies, games, architecture, interactive media, educa- tion, and industrial design. Typically, 3D models are cre- ated with off-the-shelf 3D modeling software. These soft- ware packages offer a wide range of functionality, but the us- age is rather complex, though. Many toolbars, palettes, and filters make it difficult for non-expert users to quickly visu- alize ideas or to modify existing 3D models. The required functionality is often hidden in hierarchical menu structures and it is difficult for non-expert users to use the software without any guidance. Another issue is the spatial manipula- tion of the 3D models. Moving a 3D model in its coordinate system using a standard mouse and a keyboard is rather dif- ficult, since it is often unclear how the 2D input values of the mouse are mapped to the 3D position values of the 3D model. Simple tasks such as positioning or rotating an ob- ject remain difficult to accomplish, might take very long and cannot be done intuitively by novice users. Augmented Reality (AR) environments [Azu95] have the potential to offer more intuitive user interfaces for the manipulation of 3D models. Tangible User Interfaces (TUIs) [IU97], for example, allow users to grasp and manip- ulate 3D models by coupling them to physical placeholders. Typically, a placeholder is linked to a virtual object, thus the state of the real, physical object directly represents the state of the linked virtual object. TUIs are frequently used in AR environments to manipulate the position and orientation of a 3D model. In applications of 3D graphical design or mod- eling, the offered interaction metaphors block many natural abilities and force complexity on what might be done very simple. For non-spatial tasks, such as modifying the color or texture of a 3D model, further concepts for 3D user inter- faces are required. This paper presents a table-top AR environment for 3D modeling that combines TUIs with 3D widgets, a gaze-based view pointer and speech commands. The environment is not intended to replace existing desktop modelling software. Compared to desktop modelling software, the table-top AR environment offers only limited and rather basic functional- ity. Instead, we wanted to show that there are intuitive AR- based interaction techniques for 3D modelling allowing non- c  The Eurographics Association 2006.