Avatar-Based 3D User Interface Design For Children

With the rise of virtual environments, augmented reality and three-dimensional display techniques, traditional user interfaces weren't sufficient to address the unique needs of these systems where interaction took place in a 3D spatial context, with multiple degrees-of-freedom. These 3D applications require new human-computer interaction in which the user's tasks are performed directly in 3D spatial context. 3D user interfaces are the ones involve such 3D interactions. Although 3D UI researchers and application developers have been successful in identifying basic user tasks and interaction metaphors, evaluating and improving the usability of 3D interaction techniques, 3D user interface design still can't follow a common design guidelines as 2D user interfaces. Different devices, user groups and applications themselves will lead to different 3D user interface designs.What works for adults will not necessarily work for children; however, most of the people designing and creating the user experience today still have not designed for children as a user group. As the development of children's spatial sense grows, traditional 2D user interfaces are not sufficient. More children will find an increasing need to use 3D user interfaces, and to help them understand the spatial information in both educational and entertaining 3D media applications. 3D user interfaces design for children still have empty spots to explore.Avatars are user-controlled manifestations of self in a virtual world and are designed to enhance interaction in virtual space. Avatars are widely used in virtual environments. Avatar-based approach to 3D user interface design provides children with natural immersive experience in virtual environments. But they also have many constraints in psychology, spatial sense and input/output device interaction behaviors. Our avatar-based approach takes an extensive use of avatar information and provides interaction techniques to help them understand spatial relationships, encourage their creativity and customize to their interaction styles, which in turn improve the usability of the 3D user interfaces for children.The main contribution of this paper is the first avatar-based approach of 3D user interface design for children. The prototype application used in the paper is a 3D content creation game. We introduce a novel 3D user interface scheme and its application to improve children's experience with 3D content creation applications or 3D games. We demonstrate a complete suite of our avatar-based interaction techniques, including navigation, position, selection and manipulation. These techniques cover highly frequent professional 3D editing jobs, such as 3D terrain editing and texturing, 3D object creation and manipulation with aesthetic or functional goals, 3D scene composing with high spatial complexity, self-motivated story making in 3D worlds, and some kids-invented methods of 3D navigation and path-finding by modifying the environment and applying physical laws. This paper shows that how the frequent and perplexing manipulations of 3D user interface used by adult professionals could be redesigned and accomplished so successfully by children aged 7-12 without losing interests.This article also proposes a Human Computer Interaction (HCI) framework from the representative application we have developed. The application is the online version of our 3D content creation game with distributed game world logic, provided by a programming language environment used in constructing distributed neural network and its visualizations. HCI concepts are described in abstract terms in the framework, which is useful to avatar-based user interface or other different design concepts. These include off-line presentation of global entities, entities inside a hierarchical namespace, communication and languages, reconfiguration of entity references in a graph, impersonation and access right, etc.