text-to-cad-program-generation-final-geometry-similarity-iou-against-reference-solid CLM-0223
observationsingle paperReviewed by AI

For text-to-CAD program generation, final-geometry similarity (IoU against a reference solid) carries almost no information about whether the generated program preserves the intended construction process: on multi-entity Text2CAD samples with Qwen3, sample-level IoU and a constraint-satisfaction rate over expected entities, Boolean roles, sketch properties and inter-entity relations correlate near zero (Pearson r = 0.022, Spearman 0.023), and high-IoU programs can omit expected entities or invert additive/subtractive roles.

Capability: Whether the measurement made the finding

Observed on

Multi-entity CadQuery programs generated from natural-language descriptions, 26,783 samples derived from Text2CAD; correlation measured on one backbone (Qwen3), on programs that ex.

Sources

  • Measured: sample-level Pearson and Spearman between normalized IoU and CSR on one backbone, plus a qualitative case (IoU 90.41% with CSR 10.00%). Aggregate tables across three backbones show IoU and CSR moving by very different amounts. The design does not isolate how much of the low correlation is error in the LLM-inferred expected constraints, since no human-audited constraint ground truth is reported.
Reviewed by AI (Claude Opus 5)Last checked: 2026-09-18Evidence activity: not checked yet
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Notes

Drafted from the paper by a model and filed unreviewed. Visible here so it can be read, not because anyone has vouched for it: it does not move any technique's standing and does not count toward the internal scorecard. Drafted confidence: medium. Falsifier as drafted: Measuring IoU against a construction-level constraint score on a comparable multi-entity CAD set and finding a strong positive correlation, or showing the near-zero correlation comes from noise in the LLM-inferred constraint set rather than from real construction errors. Drafted stance toward function-level-algorithmic-tasks-translated-c-model-s-functional-test: supports -- Both find that a pass/similarity-style correctness metric decorrelates from other quality dimensions of the generated code, here construction-structure correctness in CAD programs. Proposed technique, not catalogued: Constraint intent tree for CAD generation and verification.