DiffCheck: a Scan-CAD Evaluation Tool for Digital Manufacturing and Assembly Processes in Timber Construction

2025-02-21

AI Summary

To address the challenge of efficiently quantifying discrepancies between as-scanned point clouds and as-designed CAD models in digital timber construction, this paper introduces DiffCheck—the first open-source Scan-CAD deviation analysis framework tailored for timber digital fabrication. DiffCheck integrates high-precision point cloud registration and voxel-based deviation quantification via a hybrid C++/Python implementation, supporting multi-source scan data including LiDAR and photogrammetry. A Grasshopper plugin enables seamless design-to-inspection feedback loops, facilitating applications in robotic assembly, augmented reality (AR)-assisted carpentry, and CNC machining. Its lightweight, modular architecture ensures cross-process and cross-material scalability, validated across diverse timber components and fabrication workflows. The project releases fully open-source code and a benchmark dataset, establishing the first comprehensive toolchain for accuracy assessment in timber digital construction.

Technology Category

Intelligent Robots: Multimodal Perception & Sensor FusionComputer Vision: Diffusion Models for VisionConstraint Satisfaction and Optimization: Solvers and Tools

Application Category

Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deploymentsWeb Mining and Content Analysis: Web data provenance, reliability, and authenticitySearch and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

In digital timber construction, scanning technologies and point cloud data are widely used due to the accessibility of affordable 3D sensors, photogrammetry, and user-friendly CAD tools. While typically not employed for accuracy checks in timber fabrication due to the precision of standard machinery, experimental research and prototyping with joinery and assembly can benefit from precision and accuracy evaluation tools. We introduce diffCheck, a C++/Python software integrated into Grasshopper to address this need. It uses advanced point cloud analysis to compare scans of fabricated timber structures with their respective CAD models, helping to identify discrepancies. Tested on various timber elements and digital fabrication methods like robotic assembly, AR-assisted woodworking, and CNC machining, diffCheck aims to establish a user-friendly benchmark framework for digital fabrication systems using timber components, with the potential to find applications in other materials. Its source code and the analyzed data are openly shared with the digital fabrication community under a permissive license.

Problem

• Develops a tool for precision evaluation
• Compares fabricated timber scans with CAD models
• Establishes a benchmark for digital fabrication systems

Innovation

• Point cloud analysis tool
• CAD model comparison
• Open-source software integration