我试图找到一个等价物,但我正在努力找到解决问题的办法。 我有两条在python中定义为2D列表的曲线。我想找到曲线1到曲线2的正交投影。 我开始这样做:
import numpy as np
import matplotlib.pyplot as plt
def unit_tangent_vector(curve):
tangent_vectors = np.diff(curve,axis=0)
unit_tangent_vectors = tangent_vectors / np.linalg.norm(tangent_vectors,axis=1)[:,None]
return unit_tangent_vectors
curve_1 = np.array([[ 0. ,1050.45881 ]
[ 54.4012659,1050.45924 ]
[ 108.772202 ,1050.46115 ]
[ 163.063568 ,1050.46476 ]
[ 217.210682 ,1050.47023 ]
[ 271.123361 ,1050.47781 ]
[ 324.675052 ,1050.48779 ]
[ 377.692745 ,1050.50048 ]
[ 427.845685 ,1053.07373 ]
[ 461.323846 ,1068.71938 ]
[ 494.723661 ,1084.33569 ]])
curve_2 = np.array([[ 0., 1050.56801 ]
[ 51.8993183 ,1050.56801 ]
[ 103.798637 ,1050.56801 ]
[ 155.697955 ,1050.56801 ]
[ 207.597273 ,1050.56801 ]
[ 259.496592 ,1050.56801 ]
[ 311.39591 ,1050.56801 ]
[ 363.295228 ,1050.56801 ]
[ 415.191677 ,1050.56813 ]
[ 455.961611 ,1065.59296 ]
[ 495.02527 ,1083.69965 ]])
curve_1_tangents = unit_tangent_vector(curve_1)
curve_1_tangents = np.vstack([curve_1_tangents,curve_1_tangents[-1]]) # Need to have the same number of values as the curve
curve_2_tangents = unit_tangent_vector(curve_2)
curve_2_tangents = np.vstack([curve_2_tangents,curve_2_tangents[-1]])
ndots = np.einsum('ij,ij->i', curve_1_tangents, curve_2_tangents)
w_vector = curve_2 - curve_1
si = -np.array([t_le.dot(w) for t_le, w in zip(curve_1, w_vector)]) / ndots
psi = w_vector + si[:,None]*curve_2_tangents+curve_1 # Intersections
ax = plt.figure().gca()
ax.plot(curve_1.T[0],curve_1.T[1],marker="o",color="blue")
ax.plot(curve_2.T[0], curve_2.T[1], color="red")
ax.scatter(psi.T[0], psi.T[1], marker="x", color="green")
n = 8
ax.quiver(curve_1[n][0], curve_1[n][1], curve_1_tangents[n][0], curve_1_tangents[n][1],color="grey")
ax.quiver(curve_2[n][0],curve_2[n][1],curve_2_tangents[n][0],curve_2_tangents[n][1])
plt.show()
然而,切线计算似乎不正确,并导致错误的结果。例如,如果我运行此代码,它将为我提供:
我应该有青色的交叉点。 比如说,灰色切线向量是平面的法线。我想找到每个平面(蓝色曲线的所有点)和红色曲线之间的交点。我不是在寻找两条曲线之间的交点
基本上,此函数仅适用于一个平面和一条直线:
def find_intersection(plane_normal,plane_point,ray_direction,ray_point):
epsilon=1e-6
ndotu = plane_normal.dot(ray_direction)
if abs(ndotu) < epsilon:
print ("no intersection or line is within plane")
w = ray_point - plane_point
si = -plane_normal.dot(w) / ndotu
Psi = w + si * ray_direction + plane_point #intersections
我只想把它扩展到一个包含几个点的numpy数组
谢谢你的帮助
目前没有回答
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