• Parametric and algebraic surface representations—Bezier/B-spline curves, Coons-type surfaces, and quadric-boundaries—became foundational for CAD, enabling interpolation, smooth surface fitting, and mixed curve-surface design across multiple models [1], [2], [4], [18], [19].

• Line-drawing processing, sequential illumination, and curved-surface display addressed how humans perceive 3D forms from projections, supporting CAD visualization and interpretation of geometry [3], [5], [7].

• Optimization-driven CAD workflows emphasize systematic improvement, from design-optimization methods and second-order designs to optimum system designs and rigorous logical verification, enabling efficient and reliable CAD pipelines [10], [12], [16], [17].

• Shape analysis and geometry processing examine shape optimization, joint geometry, and orientation for manufacturability and physical realization, incorporating fractal-like analyses and differential-geometry concepts [6], [14], [15], [18].

• Software engineering of CAD tools emphasized graphics-package design, system verification, and digital design-logic simulation to improve robustness and usability of CAD workflows [8], [10], [12], [20].