用相似变换与三角网格“铺设”绘制表面
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该范例演示如何从基础几何元素出发,通过相似变换(含伸缩/平移与镜像等操作)构造并“铺设”可绘制的表面效果。核心数学概念包括:相似变换与相似比(dilation/缩放)、三角形构造、几何元素的中点与重心、以及向量与坐标关联的几何关系;同时利用射线、直线交点等确定局部几何。作图要点:在 GeoGebra 中使用 Vector、Translate、Circle、Point、Ray、OrthogonalLine、Mirror、Segment、facecachée3points、Polygon、fachequadrlatèrecachée、Midpoint、Line、Intersect、Centroid 等命令;对象方面通过高度/长度参数(如 Hauteur、Length)、基点与中间量(如 O、A1、B、P、Q、R、S、T、U、V、W、Z_1)以及视图/缩放变量(如 Zoom、Vue、k、l、m、n)来组织网格与表面片元,并用面类对象(facecachée3points、fachequadrlatèrecachée)呈现表面。适合中学高年级到大学初级阶段的几何建模、相似变换与立体/曲面可视化的教学演示,也适合作为 GeoGebra 几何作图练习与项目式学习素材。
GeoGebra 命令及参数
Vector(B, Z) → wVector(B, X) → uTranslate(O, Vector[(Length * u)]) → PVector(B, Y) → vTranslate(P, Vector[(Width * v)]) → QCircle(Vue, 0.2) → dPoint(d) → CRay(Vue, C) → e_2OrthogonalLine(Vue, yAxis) → aOrthogonalLine(Vue, xAxis) → bTranslate(Q, Vector[(Hauteur * w)]) → RMirror(R, O) → SMirror(R, Q) → TMirror(T, P) → UMirror(R, P) → VMirror(U, O) → WMirror(T, O) → Z_1Mirror(V, O) → A1Segment(Z_1, U) → kSegment(U, V) → lSegment(V, T) → mSegment(T, W) → nSegment(W, A1) → pSegment(A1, Z_1) → qSegment(A1, R) → rSegment(R, T) → sSegment(R, U) → tSegment(Z_1, S) → a1Segment(S, W) → b1Segment(S, V) → c1facecachée3points(W, S, Z_1) → B1facecachée3points(Z_1, A1, S) → C1Polygon(C1, A1, B1, S) → poly2, c1_1, a1_1, b1_1, s_1fachequadrlatèrecachée(Z_1, U, V, S) → poly4, d1, f1, j1, k1fachequadrlatèrecachée(A1, R, U, Z_1) → poly5, l1, m1, n1, p1fachequadrlatèrecachée(W, S, V, T) → poly6, q1, r1, s1, t1fachequadrlatèrecachée(U, R, T, V) → poly7, a2, b2, c2, d2fachequadrlatèrecachée(R, A1, W, T) → poly8, e2, f2, g2, h2Polygon(S, W, T, V) → poly1, s_2, w_1, t_1, v_1Midpoint(Z_1, R) → ATranslate(A, Vector[(Expand * w)]) → DTranslate(R, Vector[(Expand * w)]) → ETranslate(A1, Vector[(Expand * w)]) → FTranslate(Z_1, Vector[(Expand * w)]) → GTranslate(U, Vector[(Expand * w)]) → HPolygon(F, E, H, G) → poly3, f_1, e_1, h_1, g_1Mirror(F, O) → F'Mirror(E, O) → E'Mirror(H, O) → H'Mirror(G, O) → G'Polygon(F', E', H', G') → poly3', f', e', h', g'Translate(R, Vector[(Expand * u)]) → ITranslate(T, Vector[(Expand * u)]) → JTranslate(U, Vector[(Expand * u)]) → KTranslate(V, Vector[(Expand * u)]) → LPolygon(K, I, J, L) → poly9, k_1, i_1, j, l_1Mirror(K, O) → K'Mirror(I, O) → I'Mirror(J, O) → J'Mirror(L, O) → L'Polygon(K', I', J', L') → poly9', k', i', j', l'Translate(A1, Vector[(Expand * v)]) → MTranslate(R, Vector[(Expand * v)]) → NTranslate(W, Vector[(Expand * v)]) → D1Translate(T, Vector[(Expand * v)]) → E1Polygon(M, D1, E1, N) → poly10, m_1, d1_1, e1, n_1Mirror(M, O) → M'Mirror(D1, O) → D1'Mirror(E1, O) → E1'Mirror(N, O) → N'Polygon(M', D1', E1', N') → poly10', m', d1', e1', n'Midpoint(n') → A_1Midpoint(A_1, M') → B_1Midpoint(B_1, M') → C_1Midpoint(B_1, A_1) → D_1Midpoint(B_1, C_1) → E_1Midpoint(C_1, M') → F_1Line(F_1, m') → eLine(E_1, e) → gMidpoint(e1') → G_1Midpoint(G_1, E1') → H_1Midpoint(H_1, E1') → I_1Line(I_1, d1') → hIntersect(h, g) → J_1Intersect(e, h) → K_1Polygon(E1', D1', M', F_1, K_1, J_1, E_1, N') → poly11, e1'_1, d1'_1, m'_1, f_2, k_2, j_1, e_3, n'_1Midpoint(m_1) → L_1Midpoint(D1, L_1) → M_1Line(M_1, d1_1) → iMidpoint(L_1, M) → N_1Line(N_1, i) → a_1Midpoint(D1, E1) → O_1Midpoint(O_1, E1) → P_1Line(P_1, e1) → b_1Line(O_1, m_1) → c_1Intersect(a_1, c_1) → Q_1Intersect(c_1, i) → R_1Intersect(b_1, i) → S_1Intersect(a_1, b_1) → T_1Polygon(N, M, D1, O_1, Q_1, T_1, S_1, P_1, E1) → poly12, n_2, m_2, d1_2, o_1, q_1, t_2, s_3, p_1, e1_1Polygon(S_1, R_1, O_1, P_1) → poly13, s_4, r_1, o_2, p_2Midpoint(Q_1, T_1) → U_1Midpoint(R_1, S_1) → V_1Midpoint(Q_1, R_1) → W_1Midpoint(W_1, R_1) → A_2Midpoint(W_1, Q_1) → B_2Segment(U_1, V_1) → d_1Midpoint(T_1, S_1) → C_2Midpoint(C_2, T_1) → D_2Midpoint(C_2, S_1) → E_2Segment(B_2, D_2) → a_2Segment(W_1, C_2) → b_2Segment(A_2, E_2) → c_2Midpoint(Q_1, U_1) → F_2Midpoint(U_1, T_1) → G_2Midpoint(R_1, V_1) → H_2Midpoint(V_1, S_1) → I_2Segment(F_2, H_2) → d_2Segment(G_2, I_2) → g_2Polygon(Q_1, T_1, S_1, R_1) → poly14, q_2, t_3, s_5, r_2Polygon(E_1, J_1, K_1, F_1) → poly15, e_4, j_2, k_3, f_3Midpoint(I, L) → J_2Midpoint(E1', M') → K_2Midpoint(L', I') → L_2Midpoint(M, E1) → M_2Midpoint(M, E1) → N_2Midpoint(E1, M) → O_2Midpoint(M, E1) → P_2Midpoint(E_1, M) → Q_2Midpoint(N, D1) → R_2Midpoint(n_1) → S_2Midpoint(d1_1) → T_2Polygon(A_3, D_3, V_2, U_2) → poly16, a_3, d_3, v_2, u_2Polygon(B_3, C_3, Z_2, W_2) → poly17, b_3, c_3, z_2, w_2Polygon(E_3, G_3, J_3, F_3) → poly18, e_5, g_3, j_3, f_4Polygon(K_3, H_3, I_3, L_3) → poly19, k_4, h_3, i_3, l_3Midpoint(D_3, U_2) → M_3Midpoint(C_3, W_2) → N_3Midpoint(J_3, E_3) → O_3Midpoint(L_3, H_3) → P_3Midpoint(U_2, V_2) → Q_3Midpoint(Q_3, V_2) → R_3Midpoint(R_3, V_2) → S_3Midpoint(R_3, Q_3) → T_3Midpoint(D_3, V_2) → U_3Midpoint(U_3, D_3) → V_3Line(V_3, a_3) → l_2Midpoint(S_3, V_2) → W_3Midpoint(R_3, W_3) → Z_3Midpoint(R_3, Z_3) → A_4Line(A_4, d_3) → h_2Line(W_3, d_3) → i_2Intersect(h_2, l_2) → B_4Intersect(l_2, i_2) → C_4Polygon(A_4, B_4, C_4, W_3) → poly20, a_4, b_4, c_4, w_3Intersect(w_2, z_2) → D_4Midpoint(C_3, Z_2) → E_4Midpoint(E_4, N_3) → F_4Midpoint(Z_2, W_2) → G_4Midpoint(Z_2, G_4) → H_4Midpoint(E_4, Z_2) → I_4Midpoint(C_3, E_4) → J_4Midpoint(b_3) → K_4Midpoint(C_3, K_4) → L_4Line(J_4, b_3) → m_3Midpoint(F_4, E_4) → M_4Line(M_4, c_3) → n_3Line(K_4, w_2) → p_3Line(I_4, z_2) → q_3Intersect(m_3, p_3) → N_4Intersect(n_3, m_3) → O_4Intersect(q_3, n_3) → P_4Intersect(p_3, q_3) → Q_4Polygon(N_4, O_4, P_4, Q_4) → poly21, n_4, o_4, p_4, q_4Polygon(R_4, S_4, U_4, T_4) → q2, r_4, r_3, u_4, t_4Centroid(poly3) → V_4Centroid(q2) → W_4Polygon(Vue, AA, BB, CC) → q3, vue, aa, bb, cc
AI 绘图提示语参考
构建一个由相似变换和三角形组成的可绘制表面。首先,通过点O和向量w、u、v、w生成一系列点和线段,然后利用镜像、旋转和平移操作创建多个四边形和三角形。最后,通过辅助点A、D、E、F等控制形状和比例,形成一个复杂的几何表面。
以上提示语为根据原始绘图命令整理而来,仅供参考。