The ability of the user of a graphics system to interactively control the motions of 3-D objects enhances his or her spatial perception and comprehension of those objects. This paper describes several logical devices based on the tablet, each particularly suited to control some type of interactive manipulation of 2-D and 3-D objects in real time. The “turntable” and the “stirrer” convert rotary motion of the tablet pen or puck into values for one-axis rotational control; the “rack”, a two-axis device, is used for scaling control; for three-axis rotational control, the tablet-based three-axis trackball is particularly suited.

A system for removing hidden edges in line displays of three dimensional scenes is described. The hardware system is relatively low cost, and operates on several hundred vectors in real-time. The system consists of a graphics peripheral connected to a PDP 11/55 computer and a software package to drive the peripheral.

A significant increase in the capability for controlling motion dynamics in key frame animation is achieved through skeleton control. This technique allows an animator to develop a complex motion sequence by animating a stick figure representation of an image. This control sequence is then used to drive an image sequence through the same movement. The simplicity of the stick figure image encourages a high level of interaction during the design stage. Its compatibility with the basic key frame animation technique permits skeleton control to be applied selectively to only those components of a composite image sequence that require enhancement.

article Computer animation of free form images Share on Authors: N. Burtnyk National Research Council of Canada, Ottawa, Ontario National Research Council of Canada, Ottawa, OntarioView Profile , M. Wein National Research Council of Canada, Ottawa, Ontario National Research Council of Canada, Ottawa, OntarioView Profile Authors Info & Claims ACM SIGGRAPH Computer GraphicsVolume 9Issue 1Spring 1975 pp 78–80https://doi.org/10.1145/964963.563743Online:01 April 1975Publication History 15citation620DownloadsMetricsTotal Citations15Total Downloads620Last 12 Months9Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access