The article discusses a technique to address the challenges associated with surface-surface intersection in computer-aided design (CAD). Surfaces, particularly non-uniform rational B-spline surfaces (NURBS), are commonly used in geometric design. However, when surfaces intersect, trimmed surfaces can emerge, leading to complexities in CAD applications.
One of the main issues with trimmed surfaces is that their parametric domain is not usually a standard shape like a square or rectangle. Instead, it is often bounded by curves. This makes it difficult for downstream applications like computer-aided engineering (CAE) to process the data effectively. Additionally, NURBS surfaces struggle to maintain a closed form when dealing with trimmed surfaces. As a result, a specialized data structure for intersection curves is typically required to support downstream applications. However, this data structure is not standardized in the CAD system, resulting in inefficient calculations.
To address these challenges, the paper proposes a reparameterization or normalization technique for Bezier surfaces, which are a specific case of NURBS. By transforming the trimmed surface into a collection of Bezier surface patches in a standard parametric domain [0,1]X[0,1], the authors aim to eliminate the trimmed surface. The boundary curve of each normalized Bezier surface patch can then be replaced by the intersection curve, resulting in a watertight representation along the boundary. This approach effectively bridges the gap between CAD and CAE, ensuring seamless integration and eliminating any gaps or overlaps that may occur during preprocessing.
Overall, this technique offers a promising solution to the challenges associated with surface-surface intersection in CAD. By normalizing trimmed surfaces into Bezier surface patches, it simplifies the data structure and improves efficiency in downstream applications. Further research and experimentation could focus on evaluating the performance of this technique with different types of surfaces and exploring its applicability to various CAD systems and workflows. Ultimately, this technique has the potential to enhance the overall accuracy and reliability of CAD models, making them more suitable for downstream analysis and applications.
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