Pointmantrade is a new virtual locomotion control that uses a conventional dual joystick gamepad combined with a tracked head-mounted display and sliding foot pedals. Unlike conventional gamepad control mappings for first person shooter games, Pointman allows users to independently specify their avatar's direction of movement and heading of the upper body. The motivation is to develop inexpensive virtual infantry training simulators that allow users to execute realistic tactical infantry movements.

The paper reports empirical results from two studies of effective user interaction in immersive virtual environments. The use of 2D interaction techniques in 3D environments has received increased attention recently. We introduce two new concepts to the previous techniques: the use of 3D widget representations; and the imposition of simulated surface constraints. The studies were identical in terms of treatments, but differed in the tasks performed by subjects. In both studies, we compared the use of two-dimensional (2D) versus three-dimensional (3D) interface widget representations, as well as the effect of imposing simulated surface constraints on precise manipulation tasks. The first study entailed a drag-and-drop task, while the second study looked at a slider-bar task. We empirically show that using 3D widget representations can have mixed results on user performance. Furthermore, we show that simulated surface constraints can improve user performance on typical interaction tasks in the absence of a physical manipulation surface. Finally, based on these results, we make some recommendations to aid interface designers in constructing effective interfaces for virtual environments.

Pre-screen projection is a new interaction technique that allows a user to pan and zoom integrally through a scene simply by moving his or her head relative to the screen. The underlying concept is based on real-world visual perception, namely, the fact that a person’s view changes as the head moves. Pre-screen projection tracks a user’s head in three dimensions and alters the display on the screen relative to head position, giving a natural perspective effect in response to a user’s head movements. Specifically, projection of a virtual scene is calculated as if the scene were in front of the screen. As a result, the visible scene displayed on the physical screen expands (zooms) dramatically as a user moves nearer. This is analogous to the real world, where the nearer an object is, the more rapidly it visually expands as a person moves toward it. Further, with pre-screen projection a user can navigate (pan and zoom) around a scene integrally, as one unified activity, rather than performing panning and zooming as separate tasks. This paper describes the technique, the real-world metaphor on which it is conceptually based, issues involved in iterative development of the technique, and our approach to its empirical evaluation in a realistic application testbed.

The Core System is a proposed standard subroutine package for line-drawing graphics. We present some Core System extensions for use with raster graphics equipment. The extensions, which are upward-compatible with the present Core System, provide filled polygons, display of arrays of pixels, use of a color look-up table, and hidden-surface or hidden-edge removal. The extensions are being intergrated into an existing Core System implementation.