Pointer-CAD: Unifying B-Rep and Command Sequences via Pointer-based Edges & Faces Selection

Fuente: arXiv
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Main Authors: Qi, Dacheng, Wang, Chenyu, Xu, Jingwei, Chu, Tianzhe, Zhao, Zibo, Liu, Wen, Ding, Wenrui, Ma, Yi, Gao, Shenghua
Format: Preprint
Published: 2026
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author Qi, Dacheng
Wang, Chenyu
Xu, Jingwei
Chu, Tianzhe
Zhao, Zibo
Liu, Wen
Ding, Wenrui
Ma, Yi
Gao, Shenghua
author_facet Qi, Dacheng
Wang, Chenyu
Xu, Jingwei
Chu, Tianzhe
Zhao, Zibo
Liu, Wen
Ding, Wenrui
Ma, Yi
Gao, Shenghua
contents Constructing computer-aided design (CAD) models is labor-intensive but essential for engineering and manufacturing. Recent advances in Large Language Models (LLMs) have inspired the LLM-based CAD generation by representing CAD as command sequences. But these methods struggle in practical scenarios because command sequence representation does not support entity selection (e.g. faces or edges), limiting its ability to support complex editing operations such as chamfer or fillet. Further, the discretization of a continuous variable during sketch and extrude operations may result in topological errors. To address these limitations, we present Pointer-CAD, a novel LLM-based CAD generation framework that leverages a pointer-based command sequence representation to explicitly incorporate the geometric information of B-rep models into sequential modeling. In particular, Pointer-CAD decomposes CAD model generation into steps, conditioning the generation of each subsequent step on both the textual description and the B-rep generated from previous steps. Whenever an operation requires the selection of a specific geometric entity, the LLM predicts a Pointer that selects the most feature-consistent candidate from the available set. Such a selection operation also reduces the quantization error in the command sequence-based representation. To support the training of Pointer-CAD, we develop a data annotation pipeline that produces expert-level natural language descriptions and apply it to build a dataset of approximately 575K CAD models. Extensive experimental results demonstrate that Pointer-CAD effectively supports the generation of complex geometric structures and reduces segmentation error to an extremely low level, achieving a significant improvement over prior command sequence methods, thereby significantly mitigating the topological inaccuracies introduced by quantization error.
format Preprint
id arxiv_https___arxiv_org_abs_2603_04337
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Pointer-CAD: Unifying B-Rep and Command Sequences via Pointer-based Edges & Faces Selection
Qi, Dacheng
Wang, Chenyu
Xu, Jingwei
Chu, Tianzhe
Zhao, Zibo
Liu, Wen
Ding, Wenrui
Ma, Yi
Gao, Shenghua
Computer Vision and Pattern Recognition
Computation and Language
Constructing computer-aided design (CAD) models is labor-intensive but essential for engineering and manufacturing. Recent advances in Large Language Models (LLMs) have inspired the LLM-based CAD generation by representing CAD as command sequences. But these methods struggle in practical scenarios because command sequence representation does not support entity selection (e.g. faces or edges), limiting its ability to support complex editing operations such as chamfer or fillet. Further, the discretization of a continuous variable during sketch and extrude operations may result in topological errors. To address these limitations, we present Pointer-CAD, a novel LLM-based CAD generation framework that leverages a pointer-based command sequence representation to explicitly incorporate the geometric information of B-rep models into sequential modeling. In particular, Pointer-CAD decomposes CAD model generation into steps, conditioning the generation of each subsequent step on both the textual description and the B-rep generated from previous steps. Whenever an operation requires the selection of a specific geometric entity, the LLM predicts a Pointer that selects the most feature-consistent candidate from the available set. Such a selection operation also reduces the quantization error in the command sequence-based representation. To support the training of Pointer-CAD, we develop a data annotation pipeline that produces expert-level natural language descriptions and apply it to build a dataset of approximately 575K CAD models. Extensive experimental results demonstrate that Pointer-CAD effectively supports the generation of complex geometric structures and reduces segmentation error to an extremely low level, achieving a significant improvement over prior command sequence methods, thereby significantly mitigating the topological inaccuracies introduced by quantization error.
title Pointer-CAD: Unifying B-Rep and Command Sequences via Pointer-based Edges & Faces Selection
topic Computer Vision and Pattern Recognition
Computation and Language
url https://arxiv.org/abs/2603.04337