NURBS Surface Fitting for Large Mesh Representations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current CAD systems face challenges in processing and manipulating large-size mesh representations due to high memory and processing requirements, and remeshing techniques often fail to achieve high-quality results, especially when dealing with surface holes or cracks, and may not meet curvature continuity requirements.
Innovation Solution
The method involves subdividing the mesh representation into patches, computing vertex and edge boundary continuity constraints, and fitting each patch with a partial NURBS surface, which allows for precise reconstruction of the mesh representation as a single high-level smooth-surface while repairing imperfections like holes and cracks, ensuring C2 continuity between patches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a large-size mesh representation is converted into a NURBS surface to reduce memory and processing requirements, then processing efficiency is improved, but the conversion process overwhelms conventional CAD systems in terms of memory use and processing requirements when the number of control points exceeds one million
Solution Approach 1:
The patent divides the large-size mesh representation into multiple smaller patches, each of which is converted to a NURBS surface independently. This segmentation reduces the number of control points that need to be processed simultaneously, thereby reducing memory usage and processing requirements while still achieving the overall conversion goal.
Solution Approach 2:
The patent applies partial action by converting only necessary portions of the mesh to NURBS surfaces with appropriate precision levels. Not all regions require the same level of detail, so the conversion process focuses computational resources on critical areas while using coarser representations elsewhere, reducing overall system resource demands.
2Device complexity
If remeshing is applied to divide the mesh into smaller patches for conversion, then processing requirements are reduced, but high-quality results are not achieved when dealing with surface holes or cracks
Solution Approach 1:
The patent applies different processing strategies to different regions of the mesh based on local characteristics. Regions with holes or cracks are identified and handled specially with appropriate repair and filling algorithms, while regular regions undergo standard patch-based conversion. This local quality approach ensures high conversion quality in problematic areas without sacrificing processing efficiency overall.
3Manufacturing precision
If a large number of control points are included in the NURBS surface to reproduce fine details, then manufacturing precision is improved, but the conversion process overwhelms conventional CAD systems in terms of memory use and processing requirements
Solution Approach 1:
By segmenting the mesh into smaller patches before conversion, the patent enables reproduction of fine details within each patch using a manageable number of control points. The cumulative effect of all patches together reproduces the fine details of the entire large-size mesh, achieving high manufacturing precision without requiring all control points to be loaded into memory simultaneously.
4Measurement precision
If the mesh representation is used directly in CAD systems, then fine surface details are captured, but the representations are difficult to process and manipulate without noticeable performance degradation
Solution Approach 1:
The patent converts the large-size mesh into multiple smaller NURBS patches, each of which can be processed and manipulated independently and efficiently. This segmentation maintains the fine surface details of the original mesh while enabling faster processing and manipulation operations, as working with smaller patches is computationally less intensive than working with the complete large-size mesh.
Data Source
AI summary
One embodiment of the invention disclosed herein provides techniques for fitting a mesh representation that includes a plurality of mesh points with a NURBS surface. A subdividing engine subdivides the mesh representation into a plurality of patches in a parametric domain. A vertex solving engine computes one or more vertex boundary continuity constraints for each vertex included in a plurality of vertices associated with the plurality of patches. An edge solving engine computes one or more edge boundary continuity constraints for each edge included in a plurality of edges associated with the plurality of patches. A patch solving engine fits a first patch included in the plurality of patches with at least one partial NURBS surface based on the vertex boundary continuity constraints and the edge boundary continuity constraints.