CLRerNet is a lane-detection model built for painted lines on roads — a close match to sail stripes. But it can only draw a stripe as one x-value per row, so it would break on a stripe that curls backward. This test proves that almost never happens on real sails. Test 3.2 (the actual CLRerNet fine-tune) is cleared to proceed.
| Tier | Meaning | Violation rate |
|---|---|---|
| Tolerant (primary, jitter-safe) | Backward step > 1% of the stripe's own span | 1.28% |
CLRerNet (a self-driving lane-detection model, test 3.2) can only be used if every stripe is "single-valued" — never doubling back on itself once you look at it sideways (luff→leech). This test checked all 332 holdout photos' labels for stripes that curl back. Only 1.28% do, well under the go/no-go bar of 2-3%.
Source: 332-photo holdout, frozen 2026-08-25. Geometry-only check on stored label points, no model run.