Recent program synthesis techniques help users customize CAD models(e.g., for 3D printing) by decompiling low-level triangle meshes to Constructive Solid Geometry (CSG) expressions. Without loops or functions, editing CSG can require many coordinated changes, and existing mesh decompilers use heuristics that can obfuscate high-level structure. This paper proposes a second decompilation stage to robustly "shrink" unstructured CSG expressions into more editable programs with map and fold operators. We present Szalinski, a tool that uses Equality Saturation with semantics-preserving CAD rewrites to efficiently search for smaller equivalent programs. Szalinski relies on inverse transformations, a novel way for solvers to speculatively add equivalences to an E-graph. We qualitatively evaluate Szalinski in case studies, show how it composes with an existing mesh decompiler, and demonstrate that Szalinski can shrink large models in seconds.

中文翻译：

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用等式饱和和逆变换合成结构化 CAD 模型

最近的程序综合技术通过将低级三角形网格反编译为构造实体几何 (CSG) 表达式，帮助用户定制 CAD 模型（例如，用于 3D 打印）。如果没有循环或函数，编辑 CSG 可能需要许多协调的更改，并且现有的网格反编译器使用可以混淆高级结构的启发式方法。本文提出了第二个反编译阶段，以使用地图和折叠运算符将非结构化 CSG 表达式稳健地“缩小”为更可编辑的程序。我们展示了 Szalinski，这是一种使用 Equality Saturation 和保留语义的 CAD 重写来有效搜索较小的等效程序的工具。Szalinski 依赖于逆变换，这是求解器推测性地向 E-graph 添加等价的一种新方法。我们在案例研究中对 Szalinski 进行定性评估，