螺旋楼梯的对数螺旋

GeoGebra 命令及参数

1. CurveCartesian(x(O) + (a * cos(k)), y(O) + (a * sin(k)), z(O) + (b * k), k, 0, (2 * (π * L))) → c
2. Point(zAxis) → A
3. Ray(A, B) → f
4. Intersect(f, g) → C
5. Segment(A, C) → i
6. Sequence((x(O) + (a * cos(k)), y(O) + (a * sin(k)), z(O) + (b * k)), k, 0, ((2 * π) * L), (2 * π / n)) → l1
7. Sequence((x(O) + ((a - 0.8) * cos(k)), y(O) + ((a - 0.8) * sin(k)), z(O) + (b * k)), k, 0, ((2 * π) * L), (2 * π / n)) → l2
8. Sequence(Segment[Element[l1, i], Element[l2, i]], i, 1, Length[l1]) → l3
9. Sequence((x(O) + (((r_0 - 0.45) * aa^(t + α)) * cos(t)), y(O) + (((r_0 - 0.45) * aa^(t + α)) * sin(t)), z(O)), t, (-4.5 * π), π + α, π / (n + 1)) → l5
10. Sequence((x(O) + ((a * ℯ^((i * h))) * cos(i)), y(O) + ((a * ℯ^((i * h))) * sin(i)), z(O)), i, 0, ((2 * π) * L) - 5, (2 * π / n)) → l4
11. Segment(O, A) → k
12. CurveCartesian(x(O) + ((a - 0.8) * cos(k)), y(O) + ((a - 0.8) * sin(k)), z(O) + (b * k), k, 0, ((2 * π) * L)) → j
13. CurveCartesian(x(O) + (((a - 0.8) * ℯ^((i * h))) * cos(i)), y(O) + (((a - 0.8) * ℯ^((i * h))) * sin(i)), z(O), i, 0, ((2 * π) * L) - 5) → l
14. Sequence((x(O) + (((r_0 + 0.45) * aa^(t + α)) * cos(t)), y(O) + (((r_0 + 0.45) * aa^(t + α)) * sin(t)), z(O)), t, (-4.5 * π), π + α, π / (n + 1)) → l7
15. CurveCartesian(x(O) + ((r_0 * a^(t + α)) * cos(t)), y(O) + ((r_0 * a^(t + α)) * sin(t)), z(O), t, (-4 * π), π + α) → m
16. Sequence(Segment[Element[l7, i], Element[l5, i]], i, 1, Length[l7]) → l6
17. CurveCartesian(x(O) + (((r_0 + 0.45) * aa^(t + α)) * cos(t)), y(O) + (((r_0 + 0.45) * aa^(t + α)) * sin(t)), z(O), t, (-4.5 * π), π + α) → o
18. CurveCartesian(x(O) + (((r_0 - 0.5) * aa^(t + α)) * cos(t)), y(O) + (((r_0 - 0.5) * aa^(t + α)) * sin(t)), z(O), t, (-4.5 * π), π + α) → e
19. Sphere(D, 0.15) → q
20. Segment(D, A) → r
21. Intersect(r, q) → E,
22. Sphere(E + (0, 0, 0.05), 0.1) → s