ParaSketchFM: Joint Continuous–Discrete Flow Matching for Parametric CAD Sketch Generation

Despite substantial progress in parametric CAD sketch generation, existing generators still exhibit primitive-type distribution discrepancies on SketchGraphs, leaving room to improve generation quality and distributional fidelity. We therefore introduce ParaSketchFM, a joint discrete–continuous flow-matching model with geometric regularization. The model couples absorbing categorical paths with continuous geometric flows over unordered primitive sets and incorporates a one-sided anchor-distance regularizer, addressing two key challenges: matching primitive-type distributions and mitigating geometric contraction during joint generation. Under a shared evaluation protocol on SketchGraphs, ParaSketchFM achieves an FID of 5.22, precision of 0.431, and recall of 0.490, with a maximum per-type slot-frequency deviation from the test set of 0.31 percentage points. These results establish a new performance benchmark under this protocol.