This is the direct response to the critique: the underside should not be globally preserved. These trials classify the top-visible shell, delete/gut the rest, optionally add a tiny underside cap, then reduce from the original source FBX.
purest answer to the critique: underside is deleted instead of capped; best top-view match and true 99% reduction
best sealed/gutted candidate at the 99% budget: visible top skin plus a tiny 18-triangle convex underside cap
most aggressive face deletion at 99% while still carrying a low-poly underside cap
stress test below the ask: 200 triangles / 99.38% reduction to show where the silhouette starts giving up
slightly larger cap candidate showing the tradeoff between top read and a small triangle bump
higher-budget cap candidate; useful if 323 triangles is too harsh for tread readability
planar-cleanup variant at the same target; included because planar cleanup did not help the top read
wider visibility cone candidate; preserves more side-context before collapse but scores worse from above
wide-cone higher-budget reference; better top SSIM but misses the 99% target
silhouette-heavy reference; shows what happens when we preserve too much context and stop treating underside as disposable
| Rank | Result | Triangles | Reduction | Faces deleted pre-cap | Cap tris | Top SSIM | Download |
|---|---|---|---|---|---|---|---|
| 1 | u09_top_only_open_323 Top visible skin only, open underside — 323 tris | 322 | 99.00% | 11,620 | 0 | 0.942930 | FBX |
| 2 | u01_visible_skin_323 Visible top skin + convex underside cap — 323 tris | 322 | 99.00% | 11,620 | 18 | 0.906154 | FBX |
| 3 | u04_strict_top_323 Strict top-facing skin + underside cap — 323 tris | 323 | 99.00% | 15,239 | 16 | 0.901879 | FBX |
| 4 | u08_overshoot_200 Visible skin + underside cap stress test — 200 tris | 200 | 99.38% | 11,620 | 14 | 0.900171 | FBX |
| 5 | u02_visible_skin_450 Visible top skin + convex underside cap — 450 tris | 449 | 98.61% | 10,477 | 20 | 0.905511 | FBX |
| 6 | u03_visible_skin_650 Visible top skin + convex underside cap — 650 tris | 650 | 97.99% | 9,640 | 24 | 0.909322 | FBX |
| 7 | u07_planar_cap_323 Visible skin + planar cleanup + underside cap — 323 tris | 322 | 99.00% | 10,477 | 18 | 0.894475 | FBX |
| 8 | u05_wide_cone_323 Wide camera-cone skin + underside cap — 323 tris | 323 | 99.00% | 7,053 | 18 | 0.892451 | FBX |
| 9 | u06_wide_cone_800 Wide camera-cone skin + underside cap — 800 tris | 799 | 97.52% | 6,414 | 24 | 0.911040 | FBX |
| 10 | u10_silhouette_bias_1200 High-silhouette top skin + cap reference — 1,200 tris | 1,200 | 96.28% | 2,491 | 28 | 0.925446 | FBX |