副伞面曲面(Parasolic surface)可视化

副伞面曲面(Parasolic surface)可视化
几何画板及绘图内容加载中,请稍等……
2020-09-07 02:16
本范例演示“副伞面”这类由规则几何构造得到的曲面随参数变化的形态。核心数学概念包括:空间曲面(Surface)的生成、由参数与圆相关几何关系形成的曲面骨架、以及利用曲线/线段的分段与点的构造来搭建曲面;同时涉及用于扫掠建模的几何序列(Sequence)思想。作图要点:依据构造摘要可使用 GeoGebra 命令 CurveCartesian、Surface、Midpoint、Sequence、Segment、Circle;通过对象 O、P 等基准点、半径/参数相关的 R 与 amplitude、c、f(振幅与频率等参数)、以及在扫掠过程中生成的一系列点(如 A1…A15、B1…B17 等)和中点(Midpoint)来组织曲面网格/支撑曲线,最终用 Surface 将这些离散截线或控制元素连成副伞面。适合中学高阶到大学的几何建模、立体可视化与数学建模课程使用,也可作为微积分前置的曲面直观展示与GeoGebra作图练习。

GeoGebra 命令及参数

  1. CurveCartesian(x(O) + sin((ondes * t)) / amplitude, y(O) + (R * sin(t)), z(O) + (R * cos(t)), t, 0, (3 * π)) → c
  2. Surface(x(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)), u, A14, A15, v, 0, 1) → B14
  3. Surface(x(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)), u, A15, A16, v, 0, 1) → B15
  4. Surface(x(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)), u, A16, A17, v, 0, 1) → B16
  5. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, 0, (5 * π), v, 0, 1) → S_2
  6. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A1, A2, v, 0, 1) → B1
  7. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A2, A3, v, 0, 1) → B2
  8. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A3, A4, v, 0, 1) → B3
  9. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A4, A5, v, 0, 1) → B4
  10. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A5, A6, v, 0, 1) → B5
  11. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A6, A7, v, 0, 1) → B6
  12. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A7, A8, v, 0, 1) → B7
  13. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A8, A9, v, 0, 1) → B8
  14. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A9, A10, v, 0, 1) → B9
  15. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A10, A11, v, 0, 1) → B10
  16. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A11, A12, v, 0, 1) → B11
  17. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A12, A13, v, 0, 1) → B12
  18. Surface(x(O) + ((1 - f(v)) * x(c(u))) + (v * x(P)) - 2, y(O) + ((1 - f(v)) * y(c(u))) + (v * y(P)), z(O) + ((1 - f(v)) * z(c(u))) + (v * z(P)), u, A13, A14, v, 0, 1) → B13
  19. Midpoint(P, O) → C
  20. CurveCartesian(x(C) + sin((ondes * t)) / amplitude, y(C) + (R / 2 * sin(t)), z(C) + (R / 2 * cos(t)), t, 0, (3 * π)) → a
  21. Sequence((x(C) + sin((ondes * t)) / amplitude + 1.25, y(C) + (R / 2 * sin(t)), z(C) + (R / 2 * cos(t))), t, 0, (3 * π), (2 * π / 20)) → l1
  22. Sequence((x(O) + sin((ondes * t)) / amplitude, y(O) + (R * sin(t)), z(O) + (R * cos(t))), t, 0, (3 * π), (2 * π / 20)) → l2
  23. Sequence(Segment[Element[l1, i], Element[l2, i]], i, 1, Length[l1]) → l3
  24. Sequence(Segment[Element[l1, i], C], i, 1, Length[l1]) → l4
  25. Sequence(Segment[Element[l1, i], P], i, 1, Length[l1]) → l5
  26. Segment(P, D) → g
  27. Circle(P - (0.15, 0, 0), 0.3, xAxis) → e

AI 绘图提示语参考

请绘制一个伞状的三维曲面,通过把参数化的圆锥/圆形引导曲线沿高度方向逐步“摊开”组合而成。先取原点作为参考,建立两组以同一参数控制的圆周曲线:一组以振幅与频率项调制平移与相位,得到围绕竖直方向的弧线;另一组为以同样半径参数形成的圆周截面。取它们的对应点并在多个离散高度位置上进行连接,使用中点参考把第二组曲线的中心对齐,再把这些截面按高度参数从底部到顶部进行线性过渡形成多片曲面,最终合成为一个结构化的伞状曲面。
以上提示语为根据原始绘图命令整理而来,仅供参考。