3D Vector Parametric Curve View Switching Demo

This example demonstrates how parameter curves and vector objects appear differently when viewed from various perspectives in three-dimensional space. Core mathematical concepts include 3D vector construction and transformation (u₁, u₂, u₃, u₄), parametric curve plotting using CurveCartesian command, and spatial relationship of orthocenter. Construction highlights: Use CurveCartesian to draw parametric curves, define key points via Point command, extract vector components with Element, switch between viewpoints using buttons (vdirection direction vector), and display 2D/3D vectors with Selectvector. Suitable for high school and college students studying spatial analytic geometry, parametric equations, and vector algebra, as well as math teachers demonstrating 3D visualization techniques.