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Motion · 05 Keyframes
Series contents · Technology map
Stage: State and Transition · Editable example · Storage ID: motion-step-05
Goals and learning outcomes
- Learning outcome: Explain the role of Keyframes. Input case: Positions 0→100→60.
- Deliverable: A table of positions at each specified time. Connect your rationale for handling Times to the code.
Prerequisites
Prepare the results of the Stiffness and Damping exercises from Unit 4, “Physical Spring Parameters”.
Key concepts and explanations
Keyframes
An array defines intermediate targets. Its trajectory differs from a transition with only a start and an end.
Times
times sets the normalized time for each target. Array lengths and order must match.
Practice setup
First check the execution scope guidance on the example screen. The following describes the environment needed to extend the assignment in a separate project. The existing motion-01·02·03 examples are limited examples based on Motion JS animate. For React layout, AnimatePresence, and hooks exercises, install motion in a separate local React project and import from motion/react. Do not assume JSX runs directly in the editor; preserve CSP and isolation.
The linked example is a starting point. It does not implement every task below. Complete work beyond its supported scope in a separate project.
Practice tasks
- In src/day-5.tsx of a separate exercise project, configure an x array in animate and transition.times. Use the existing Unit 1·14·28 examples only as starting points.
- Input condition: Positions 0→100→60. Baseline: 0.5. Run under the baseline condition, then record observations and errors in notes/day-5.md.
- Variable to change: Intermediate time; new value: 0.2. Run again with the same input path. Deliverable to save: A table of positions at each specified time. Hypothesis to test: The intermediate target is reached earlier. Compare it with the actual results and record whether they agree and the causes of any differences.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| Intermediate time | 0.5 | 0.2 | The intermediate target is reached earlier. |
Predictions in this table are not measured results. Change one condition at a time and record why the actual result differs.
Completion criteria
- Required deliverable: A table of positions at each specified time. You have results for both the baseline and changed conditions, allowing a comparison of 2 conditions, and have recorded the input values and execution environment.
- Your explanation of the differences between the two conditions connects both concepts: Keyframes and Times. For unexpected items, give at least 1 cause or reason they remain unresolved.
Self-check
- Which processing stage does Keyframes affect in this exercise? Input case: Positions 0→100→60.
- Variable to change: Intermediate time. Hypothesis to test: The intermediate target is reached earlier. Did the actual results agree with the hypothesis? Explain your evidence in terms of Times.
Official references
Linked example and execution scope
Example source · Runtime environments and limits
Interactive Keyframes experiment with resource cleanup.
Source code and records are not overwritten automatically. Resetting an existing example also preserves your notes.