Week 12 Summaries

Exploring 3D Navigation : Combining Speed-coupled Flying with Orbiting

The introduction of this paper hits home the importance of the research the paper is doing. As they state in the paper, virtual environments generally comprise of worlds which are larger than that can be viewed from a single vantage point. In order to experience the different parts of the virtual world, it is essential for people to be able to navigate efficiently within the environment. A 3D world is only as good as how easily it lets people navigate and interact with the information within it.

The researchers in this paper attempt to build a taxonomy of various navigation methods, taking on a task oriented approach, categorizing existing navigation techniques and stating new ones. The categorize methods into three  main subtasks – exploration, to gain survey knowledge; search, to locate an object or route and to travel to it; and inspection, to establish and maintain a particular view of an object. Navigation can be understand as viewpoint control, as stated in the paper, which can be controlled using the position, orientation and speed of the virtual camera. There are a number of navigation techniques discussed. There are point-of-interest techniques, which allows users to specify in the environment where they would like to move, which use a logarithmic function to control the speed of the movement. Another technique is the Object Manipulation Technique. In this, the user drags on an object and manipulates a copy of the object, placing it in the position and orientation from which she would like to view it. When she releases the button, the copy fades away and the camera animates to the appropriate position and orientation in the world to attain the desired viewpoint of the object. Another is a Ghost copy technique, in which the user can manipulate multiple copies of the object so as to observe it from multiple viewpoints.

One approach for Search is the Inverse Fog and Scaling technique where the user manipulates the the radius of a sphere of visibility, where everything within the sphere is transparent. Another technique discussed is the Ephemeral World Compression. One technique discussed in detail is the Speed-coupled Flying with Orbiting, which allow a user to alternate between inspecting a local environment in detail vs getting an overview of the global world.

A survey of design issues in spatial input

This paper looks at Human Perception and Ergonomics concerns in designing free space 3D user interfaces. The term spatial input refers the use of input techniques in 3D spatial world using cameras and magnetic trackers instead of the standard 2D desktop techniques like the keyboard or mouse.  The human perception with 3D space is more about experiencing than understanding. There are a number of issues to consider like relative and absolute gestures, multi-sensory stimuli and head tracking.

In Ergonomic design considerations, Enabling 6 degrees of freedom in  coarse vs fine positioning is an important aspect to consider.  The authors also point that it can be awkward and tiresome to repeatedly switch between spatial input devices and traditional input devices. 3D user interface design has more complications and considerations than 2D interface design that stretch from physical abilities, mental cognition and others. It is not saying these considerations don’t apply to 2D design, because they do, but factors to take into account are much more in 3D.

Comments are closed.