PS-CAD: Local Geometry Guidance via Prompting and Selection for CAD Reconstruction

TL;DR

PS-CAD introduces a geometry-guided, step-by-step approach for CAD model reconstruction from point clouds, significantly improving accuracy over previous methods by focusing on regions needing refinement and leveraging planar prompts.

Contribution

The paper presents PS-CAD, a novel CAD reconstruction framework that incorporates geometric guidance and prompt-based selection to enhance interpretability and accuracy.

Findings

Reduces geometry errors (CD, HD) by 10% on DeepCAD dataset.

Decreases structural error (ECD) by approximately 15%.

Outperforms state-of-the-art methods across all evaluated metrics.

Abstract

Reverse engineering CAD models from raw geometry is a classic but challenging research problem. In particular, reconstructing the CAD modeling sequence from point clouds provides great interpretability and convenience for editing. To improve upon this problem, we introduce geometric guidance into the reconstruction network. Our proposed model, PS-CAD, reconstructs the CAD modeling sequence one step at a time. At each step, we provide two forms of geometric guidance. First, we provide the geometry of surfaces where the current reconstruction differs from the complete model as a point cloud. This helps the framework to focus on regions that still need work. Second, we use geometric analysis to extract a set of planar prompts, that correspond to candidate surfaces where a CAD extrusion step could be started. Our framework has three major components. Geometric guidance computation extracts the two types of geometric guidance. Single-step reconstruction computes a single candidate CAD modeling step for each provided prompt. Single-step selection selects among the candidate CAD modeling steps. The process continues until the reconstruction is completed. Our quantitative results show a significant improvement across all metrics. For example, on the dataset DeepCAD, PS-CAD improves upon the best published SOTA method by reducing the geometry errors (CD and HD) by 10%, and the structural error (ECD metric) by about 15%.