Efficient and Anti-Aliased Trimming for Rendering Large NURBS Models.

Area of Science:

• Computer Graphics
• Geometric Modeling
• Computer-Aided Design (CAD)

Background:

• Non-Uniform Rational B-Splines (NURBS) are standard for CAD model representation, simulation, and visualization.
• Existing rendering methods face limitations with tessellation and complex trimmed surfaces.

Purpose of the Study:

• To present a direct rendering method for trimmed NURBS models.
• To achieve sub-pixel precise visualization and efficient anti-aliasing.

Main Methods:

• A novel trimming method and a three-pass rendering pipeline are employed.
• The pipeline bypasses hardware tessellation limitations using a feedback mechanism.
• Screen-space footprint estimation and off-screen buffer routing are utilized for trimming and blending.

Main Results:

• The rendering system efficiently handles CAD models with tens of thousands of trimmed NURBS surfaces.
• The two-level data structure for trimming is more precise and memory-efficient than state-of-the-art methods.
• Curve coverage estimation offers an effective quality-performance trade-off for anti-aliasing.

Conclusions:

• The proposed direct rendering method offers a precise and efficient solution for trimmed NURBS models in CAD.
• The novel trimming and rendering pipeline overcome existing limitations, improving visualization quality and performance.
• This approach provides a scalable and memory-efficient solution for complex geometric data processing.