3DM: A Three Dimensional Modeler Using a Head-Mounted Display

Jeff Butterworth, Andrew Davidson, Stephen Hench and T. Marc Olano

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Summary:

This article describes an intuitive 3D modeler called 3DM which uses a head mounted display to facilitate the understanding of spacial relationships in a 3D environment. In spite of an increase in the demand for 3D models most modelers are hard to use. A large source of ambiguity with traditional modelers is caused by the use of a 2D screen to represent 6D objects, and a 2D mouse to manipulate them. 3DM sets out to overcome some of the obstacles by placing the user in a virtual 3D environment with a 6D pointing device.

Inspiration for the project was drawn from easy to use programs such as MacDraw which possessed a simplicity and ease of use, requiring no long learning curve. New techniques described, are applicable to many other programs. A 6D 2 button mouse and a simple user interface is employed with a tool palate. Its position can be fixed in space or can follow the current view. The cursor representation changes to reflect the selected tool. Exploration of the model environment can be performed by either walking for proximal excursions, or flying for more global ones. Zooming in and out and a home view button are supported. The screen image is rendered at between 15 to 30 fps.

Surfaces are created in place, and can be done in several ways. An interesting extrusion tool enables manipulation in a dynamic manner according to 6D mouse manipulation. Standard editing tools such as cut, copy, paste, undo, are present. A novel hierarchy feature enables instances of an object to be created so that changes to the parent are passed on the children.

The results emphasize the package’s efficiency, ease of use, good representation of spatial relationships between objects, and advantageous use of the 3D environment. The lack of constraints resulting in difficulties in aligning objects accurately is mentioned and a zoomable grid offered as a solution. The goals of the project have clearly been met as users freely experimented with different shapes and editing features.

Discussion:

The notion to develop an easily accessible 3D modeler using VR in the early 90’s was very forward thinking. In many regards this same goal in a simplified non VR version was taken up by sketchup as it appeared in its original form in 2000.

Although the resulting images look a little primitive from today’s perspective, for the time it is very impressive. It is a shame that a little more detail was not presented concerning the integration of the various components.

An interesting compliment to the HoloSketch paper.