Good uses
- Field guides, bestiaries, and specimen books that reward exploration
- Achievement or badge sets where each item records something the user did
- Learning checklists in which completing a group unlocks the next topic
01
Classification and repeated action
A stimulus engine is the axis of what invites another action. The visual world is chosen separately as an expression theme.
- Stimulus engine
- Collection completion
- Repeated action
- Find an item that matches a shaped blank, carry or assign it to that slot, and watch the set count rise by one.
- Core loop
- Notice the blank
- Obtain
- Place
- Next blank
- Typical feedback
- Silhouette, Set count, Completion rate, Rarity
Ethical note: Hidden rarity
Do not stoke collecting with rarity that hides drop rates or remaining counts. Give collected items a use or a story.
02
Build the sequence
Design the opening state, the input, the result, and the next actionable state as one sequence.
Opening state
A set of slots is laid out with owned items in color and missing ones as dotted silhouettes, and a count such as 5 / 6 is readable.
Input
The user drags, assigns, or registers a newly obtained item, and it snaps into the blank whose outline matches its shape.
Result and reward
The slot fills with color, the set count steps up by one, and on the final slot the whole set lights as one connected piece.
Next actionable state
The completed set opens a use or a story, and the next set appears with differently shaped blanks and where to find them.
03
Feedback across channels
Do not rely on motion or sound alone: every channel should make the change of state readable.
Visual
Visual: missing slots keep the exact outline of their item, so the user can tell what fits before owning it.
Motion
Motion: the item is drawn into its outline, settles with a short snap, and then the set links up slot by slot from the newest one.
Text, sound, and haptics
Text, sound, and haptics: a set count in the form owned / total, one placement click, and a fuller chord only when the set completes.
Without motion or audio
Without motion or audio: filled versus dotted slots, a "Registered" mark, and the updated count show the new entry on a still frame.
04
Production controls
Eight production controls decide the strength and order of the response.
Input
Drag an obtained item into its matching blank, or confirm a registration. The item must have been earned, not bought blind.
Timing
Snap the item the moment its shape overlaps the outline; let the set-wide completion response follow only after the count has updated.
Hit stop
Hold for about 100 ms on the frame the item locks into its slot, so the fit is felt before the set starts to light up.
Amplification
Light the slots one by one, then draw links between items to show how they relate. Reserve the whole-set glow for completion.
Text
Show owned / total and the name of the set. Name the missing item or where it can be found; never label a slot only as rare.
Camera
Keep the set framed in full while it fills. After completion, move to the place or ability it unlocks, then back to the next set.
Sound & haptics
One soft click per placement, a rising tone as slots link, and an optional single haptic when the last slot locks in.
Next expectation
Show the next set with differently shaped blanks and a named place to look, without timers or limited-time slots.
05
Where it works—and where it fails
Good uses, failure modes, risk, accessibility, and the boundary that keeps the engine from being used to manipulate.
Failure modes
- Collected items that have no use, so only the owned number matters
- Blank slots that show a rarity tier but no way to find the item
- Endless new sets that reopen blanks the moment one set is complete
Risk
Blanks pull hard on attention, so a set whose items have no use or story turns into counting for its own sake. Hidden rarity makes the last slot feel unreachable, which pushes users toward repeated draws or purchases to close the gap.
Accessibility
Distinguish owned and missing slots by outline, fill pattern, and label as well as color. Expose the set count and each item name as text, and make placement possible by selection, not only by dragging.
Manipulation boundary
Do not drive collecting with hidden rarity: show drop rates, remaining counts, and how each item is obtained. Never sell random chances at a missing slot, expire unfinished sets to create loss, or use the last blank to pressure payment.
06
Watch the interaction grammar
A 6-second vertical 1080×1920, 30 fps specimen with no audio, and a text alternative of what it shows.
A screen with a night greenhouse and a specimen book. The night section of the greenhouse is shut and locked, and the specimen book "Night garden" below reads 5 / 6: in the middle of a ring of glow moss, moth leaf, shade fern, night dew grass, and scent herb, only the outline of the "Night flower" is left as a dotted blank. A finger lifts the night flower from the collecting basket (collected on Moonview Hill) and carries it to the blank; on the frame it overlaps the outline it snaps in, holds for 0.1 second, gets a "Registered" stamp, and the count becomes 6 / 6. The six specimens light up one by one, then five lines (marked moth, dew, light, scent, and shade) and a dotted outer ring connect them into a relationship map of the night garden ("Relationship map complete"). Light rises from the specimens to the greenhouse, the lock comes off, and the doors of the night section slide open. In the moonlight, six plants grow in beds laid out exactly like the map; the night flower in the middle blooms in a spreading glow and moths arrive. Finally the book turns to "Water garden", whose blanks have different shapes (water lily leaf, waterside reed, lotus flower, water weed), with "Complete it to open the waterside section", the still-closed waterside section with a frog silhouette inside, and "Next collecting spot: Waterside path" at the bottom. No rarity, odds, or purchases appear.
Generated examples for this engine
No generated examples are recorded for this engine yet. The specimen is also listed in the gallery.
08
Creator-ready English prompt
A production brief you can hand directly to an AI model or a production team.
Written for this guide from the specimen and the classification; it is not the original generation prompt.
Produce a 6-second vertical UI motion sample that uses the Collection completion stimulus engine.
Repeated action: Drag an obtained item into its matching blank, or confirm a registration. The item must have been earned, not bought blind.
Opening state: A set of slots is laid out with owned items in color and missing ones as dotted silhouettes, and a count such as 5 / 6 is readable.
Trigger and timing: Snap the item the moment its shape overlaps the outline; let the set-wide completion response follow only after the count has updated.
Hit stop: Hold for about 100 ms on the frame the item locks into its slot, so the fit is felt before the set starts to light up.
Amplification: Light the slots one by one, then draw links between items to show how they relate. Reserve the whole-set glow for completion.
Text: Show owned / total and the name of the set. Name the missing item or where it can be found; never label a slot only as rare.
Camera: Keep the set framed in full while it fills. After completion, move to the place or ability it unlocks, then back to the next set.
Sound and haptics: One soft click per placement, a rising tone as slots link, and an optional single haptic when the last slot locks in.
Next promise: Show the next set with differently shaped blanks and a named place to look, without timers or limited-time slots.
Without motion or audio: filled versus dotted slots, a "Registered" mark, and the updated count show the new entry on a still frame.
Accessibility: Distinguish owned and missing slots by outline, fill pattern, and label as well as color. Expose the set count and each item name as text, and make placement possible by selection, not only by dragging.
Ethical boundary: Do not drive collecting with hidden rarity: show drop rates, remaining counts, and how each item is obtained. Never sell random chances at a missing slot, expire unfinished sets to create loss, or use the last blank to pressure payment.
Keep enough contrast for text and primary UI, and make the meaning clear in reduced-motion and no-audio settings.
Create original abstract subjects. Do not imitate existing works, characters, logos, brands, or proprietary UI.