Synthesizing Structured CAD Models with Equality Saturation and Inverse Transformations

09/26/2019
by   Chandrakana Nandi, et al.
0

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.

READ FULL TEXT
POST COMMENT

Comments

There are no comments yet.

Authors

09/26/2019

Using E-Graphs for CAD Parameter Inference

Computational fabrication is increasingly popular among end-users and ma...
03/08/2021

Quasi-structured quadrilateral meshing in Gmsh – a robust pipeline for complex CAD models

We propose an end-to-end pipeline to robustly generate high-quality quad...
10/04/2021

Differentiable 3D CAD Programs for Bidirectional Editing

Modern CAD tools represent 3D designs not only as geometry, but also as ...
06/17/2019

Topologically robust CAD model generation for structural optimisation

Computer-aided design (CAD) models play a crucial role in the design, ma...
11/19/2021

Hex Me If You Can

HEXME consists of tetrahedral meshes with tagged features, and of a work...
06/20/2019

Push-pull direct CAD modeling with movable neighboring faces for preserving G^1 connections

B-rep model editing plays an essential role in CAD and motivates the ver...
04/07/2020

egg: Fast and Extensible E-graphs

An e-graph efficiently represents a congruence relation over many expres...
This week in AI

Get the week's most popular data science and artificial intelligence research sent straight to your inbox every Saturday.