Acceleration is a net loss for tracing and drawing
Aliases: tracing · drawing · continuous control · trajectory control
What it is
For continuous-control tasks such as tracing, drawing, and path editing, acceleration is usually a net loss. The task needs a stable ratio between cursor and hand trajectory, not merely rapid arrival at a discrete endpoint. Changes in speed scale the screen trajectory even when the hand's geometric path is unchanged.
Why it happens
Continuous tasks depend on locally predictable motion and accumulate error across the whole path. Acceleration mixes speed into position mapping: equal bends can project to different curvature and length while accelerating or decelerating, forcing visual correction. Saved transport distance in discrete acquisition does not repay that continuing correction.
Studying it
Compare fixed and accelerated mappings with lines, curves, closed shapes, and real editing tasks. Record path deviation, integrated error, retracing, completion time, and perceived control. Endpoint success alone misses the quality of a continuous trajectory.
Where it stops holding
The loss concerns tasks needing spatial fidelity or reproducible motion. If continuous input controls coarse speed, camera panning, or wide-area browsing, velocity-dependent mapping can still help. Pressure, stabilisation, and brush smoothing add other drawing mappings and require separate evaluation.
Applying it
- Default to fixed mapping for drawing, path editing, and remote precision control, retaining a disableable acceleration state.
- Separate rapid panning from fine tracing with explicit tools or modes rather than one hidden curve.
- Test curve tracking and actual brush edits for path deviation, retracing, and shape distortion at speed changes.
Related
- Same group: C1.04.1 Acceleration dynamically changes gain with movement speed · C1.04.2 Acceleration disrupts a stable device-to-screen mapping · C1.04.4 Acceleration must be disableable
- Nearby: C1.03 Control-display gain · C1.08 Drag and drop
- Search terms:
continuous control·trajectory control·pointer acceleration