# Elastic-ring prompt: expand over a taper, then recover below the collar

**Original deterministic practice input; generation method untested.** No H3 call or generated output is included.

## 1. Task and boundary

Keep a closed loop identifiable while its opening changes to pass an obstacle. The ring must widen around the tapered body, clear its widest collar and narrow again around the lower stem. A slit, disappearing back half or uniformly shrinking scene would avoid the actual constraint.

## 2. Read the first frame and fixed roles

A fixed ochre mandrel has a narrow pointed upper region, a wider lower collar and a narrower stem beneath that collar. One teal ring loosely surrounds the upper taper. The back arc is occluded by the mandrel while the front arc is visible. A coral dot on the front-left ring segment marks the same material region.

Track the mandrel tip, collar corners, lower stem and the coral dot. The ring has one hole and remains a single closed band; only its shape and opening change. The oblique ellipse is a drawing convention, not a measured section, stretch ratio or material specification.

![Original input / 原创输入](/learning-assets/parallel-20261022-a/elastic-ring-over-taper-recover/first-frame.png)

## 3. Download and prepare one attempt

Use the PNG as the uploadable first frame. Keep the SVG and numbered inspection guide local for editing and review. The kit also contains both prompt languages, a blank CSV with bilingual criteria and source notes. Follow the site’s single-first-frame base image-to-video workflow: select MiniMax H3 base, put `first-frame.png` in the supported First Frame slot and leave Last Frame empty. If Add end frame is needed to expose that slot, enable it but do not supply an ending image. Do not select a Fast flow that requires paired inputs. Check the controls, offered settings and credit estimate before any later submission. The link prepares text only; it does not upload or submit. No paid generation was used to make this package.

[PNG](/learning-assets/parallel-20261022-a/elastic-ring-over-taper-recover/first-frame.png) · [SVG](/learning-assets/parallel-20261022-a/elastic-ring-over-taper-recover/first-frame.svg) · [ZIP](/learning-assets/parallel-20261022-a/elastic-ring-over-taper-recover/practice-kit.zip) · [CSV](/learning-assets/parallel-20261022-a/elastic-ring-over-taper-recover/acceptance.blank.csv) · [Review guide](/learning-assets/parallel-20261022-a/elastic-ring-over-taper-recover/review-guide.svg)

[Open prompt draft](/generator/image-to-video?model=MiniMax-H3&prompt=Use+the+supplied+original+fixed+mandrel+and+single+teal+ring.+Lock+the+camera+and+ochre+mandrel.+Move+the+ring+slowly+down+around+the+taper.+Let+its+opening+expand+progressively+to+pass+around+the+widest+collar+while+the+band+stays+one+closed+loop+with+its+coral+front-left+mark+attached.+Once+the+whole+ring+has+cleared+below+that+collar%2C+let+it+narrow+again+around+the+thinner+lower+stem+and+stop.+Keep+front%2Fback+occlusion+coherent%3A+the+rear+arc+stays+behind+the+mandrel+and+the+front+arc+remains+in+front.+No+slit%2C+cut+ends%2C+duplicate+ring%2C+solid+pass-through%2C+mandrel+shrink+or+entire-scene+scaling.+End+with+one+recovered+loop+surrounding+the+original+lower+stem.+This+is+a+visual+deformation+request%2C+not+a+material-strength+test.)

## 4. Prompt and operating sequence

```text
Use the supplied original fixed mandrel and single teal ring. Lock the camera and ochre mandrel. Move the ring slowly down around the taper. Let its opening expand progressively to pass around the widest collar while the band stays one closed loop with its coral front-left mark attached. Once the whole ring has cleared below that collar, let it narrow again around the thinner lower stem and stop. Keep front/back occlusion coherent: the rear arc stays behind the mandrel and the front arc remains in front. No slit, cut ends, duplicate ring, solid pass-through, mandrel shrink or entire-scene scaling. End with one recovered loop surrounding the original lower stem. This is a visual deformation request, not a material-strength test.
```

1. Locate the collar and the narrower stem below it. A simple cone with no narrower region would not support the requested recovery-after-clearance ending.
2. Request one downward pass. Describe gradual widening along the taper before clearance, then narrowing only after the entire ring is below the collar. Keep it around the stem.
3. In a future result, inspect the front and visible side arcs during maximum opening. Track the coral dot after recovery and check that a hidden rear arc has not become an invented break or extra free end.

## 5. Inspect an actual result

Fill timestamps, observations and pass/fail only after inspecting an actual result. The sheet contains no prefilled passes. Mark an obscured contact inconclusive instead of substituting the intended ending for evidence of the transition.

- The mandrel tip, collar and lower stem remain fixed and unchanged.
- The ring opening widens before it passes the widest collar.
- One closed band persists without a slit, free ends or an extra ring.
- The front/back overlap remains consistent while the ring descends.
- The coral mark stays attached to the same ring region through expansion and recovery.
- Recovery occurs below the collar, and the final ring still surrounds the narrower stem.

## 6. Repair one failure at a time

- Ring clips through the collar: enlarge the visible opening request before clearance, without shrinking the mandrel.
- Ring opens into a C shape: emphasize one continuous closed band and inspect its two visible sides.
- Recovery begins too early: make the lower-stem position the condition for narrowing; do not use a cut to conceal passage.

## 7. Save the ending and choose related tasks

Save the pre-collar, widest-opening and recovered observations. No allowable strain, sealing function, assembly force or real elastomer behavior is established. No generation run has been performed.

The sponge changes a solid volume between pads, while the drawstring gathers a fabric mouth using two free cord ends. This original input is a closed annulus with no ends, and its hole must clear a fixed collar before recovering around a different shaft section.

- [sponge compress release shape](/templates/sponge-compress-release-shape)
- [drawstring gather opening](/templates/drawstring-gather-opening)

Source: the illustration, geometry, prompt and checklist were authored for this package. No third-party image, bundled font, trademark or person is used. They are teaching schematics, not real-product performance evidence or H3 output. The download includes a source and rights declaration; independent review remains pending.