Summary of: Interactive Skeleton Summary of: Interactive Skeleton - - PowerPoint PPT Presentation

Summary of: Interactive Skeleton Summary of: Interactive Skeleton Techniques for Enhancing Motion Techniques for Enhancing Motion Dynamics in Key Frame Animation Dynamics in Key Frame Animation

By N. By N. Burtnyk Burtnyk and M. and M. Wein Wein Presented by Noah Kuntz Presented by Noah Kuntz

Uses a Uses a “ “stick figure stick figure” ” like skeleton with an image like skeleton with an image mapped onto it mapped onto it Allows the animator improved control over Allows the animator improved control over motion dynamics in key frame animation motion dynamics in key frame animation Increases fluidity of animation while decreasing Increases fluidity of animation while decreasing the time spent drawing key frames the time spent drawing key frames

Each frame is individually Each frame is individually drawn drawn 1 to 1 matching between 1 to 1 matching between strokes in adjacent frames strokes in adjacent frames Limited time control Limited time control through tapers through tapers No spatial motion control No spatial motion control

Rotational Control and Motion Paths Rotational Control and Motion Paths

• Limited application and complexity

Limited application and complexity

• Discontinuities at key frames

Discontinuities at key frames

Skeleton Only Morphing Skeleton Only Morphing

• High distortion

High distortion

• Discontinuities at key frames

Discontinuities at key frames

Skeleton Technique With Key Frames Skeleton Technique With Key Frames

• Complex motion with less work

Complex motion with less work

• No discontinuities

No discontinuities

Image is mapped to a Image is mapped to a polygonal mesh polygonal mesh Lines in image remain Lines in image remain continuous under continuous under distortion distortion Central Central “ “bone bone” ” line is line is manipulated while the manipulated while the surrounding polygons cling surrounding polygons cling to it to it

One key frame image (a) One key frame image (a) is mapped to a skeleton is mapped to a skeleton (b) and another image (b) and another image (c) to its skeleton (d) (c) to its skeleton (d) The line along the origin The line along the origin

• f the W axis is the bone,
• f the W axis is the bone,

the line that is the line that is manipulated throughout manipulated throughout the animation the animation

a) a) Starting and ending frames Starting and ending frames b) b) Interpolated skeletal position Interpolated skeletal position c) c) Interpolated skeletal positions Interpolated skeletal positions after frame 5 is modified after frame 5 is modified d) d) Skeletal positions after frame 9 is Skeletal positions after frame 9 is modified modified e) e) Preview with boundaries Preview with boundaries

f) Final linearly interpolated skeletons f) Final linearly interpolated skeletons g, h) Skeleton frames with curve g, h) Skeleton frames with curve smoothing smoothing i) Resulting images using the second i) Resulting images using the second starting key frame starting key frame j) Resulting images using the first j) Resulting images using the first starting key frame starting key frame

The combination of animation with The combination of animation with interpolated skeletons and traditional key interpolated skeletons and traditional key frames results in output images with no frames results in output images with no discontinuities and smooth motion control discontinuities and smooth motion control

Burtnyk Burtnyk, N. and , N. and Wein Wein, M. Interactive Skeleton , M. Interactive Skeleton Techniques for Enhancing Motion Dynamics in Key Techniques for Enhancing Motion Dynamics in Key Frame Animation. Communications of the ACM, v.19 Frame Animation. Communications of the ACM, v.19 n.10, pp. 564 n.10, pp. 564-

• 569, Oct. 1976

569, Oct. 1976.

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