Scalable Field-Aligned Reparameterization for Trimmed NURBS

TL;DR

This paper introduces a scalable, semi-automatic reparameterization pipeline for trimmed NURBS that produces watertight, simplified, and feature-aligned spline surfaces suitable for engineering analysis and CAD integration.

Contribution

It presents a novel, scalable method for automatic reparameterization of trimmed NURBS models into watertight, simplified multi-patch surfaces, enhancing CAD and IGA workflows.

Findings

Successfully reconstructs watertight spline surfaces from complex models.

Demonstrates efficiency and robustness on industry-scale examples.

Provides publicly available source code for reproducibility.

Abstract

In engineering design, one of the most daunting problems in the design-through-analysis workflow is to deal with trimmed NURBS (Non-Uniform Rational B-Splines), which often involve topological/geometric issues and lead to inevitable gaps and overlaps in the model. Given the dominance of the trimming technology in CAD systems, reconstructing such a model as a watertight representation is highly desired. While remarkable progress has been made in recent years, especially with the advancement of isogeometric analysis (IGA), there still lack a fully automatic and scalable tool to achieve this reconstruction goal. To address this issue, we present a semi-automatic and scalable reparameterization pipeline based on a scalable and feature-aligned meshing tool, QuadriFlow [1]. On top of it, we provide support for open surfaces to deal with engineering shell structures, and perform sophisticated patch simplification to remove undesired tiny/slender patches. As a result, we obtain a watertight spline surface (multi-patch NURBS or unstructured splines) with a simple quadrilateral layout. Through several challenging models from industry applications, we demonstrate the efficacy and efficiency of the proposed pipeline as well as its integration with IGA. Our source code is publicly available on GitHub [2].