python - 如何在 matplotlib 图上制作动画
问题描述
我有一个任务,我需要将 3D 立方体投影到 2D 笛卡尔平面,我已经绘制了顶点,但仍然需要以某种方式对其进行动画处理。
我尝试过使用 FuncAnimation(),但不知道它是如何工作的。我还是python的新手,所以请放轻松,谢谢。
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
A = np.array([-0.5,-0.5,-0.5])
B = np.array([0.5,-0.5,-0.5])
C = np.array([0.5,0.5,-0.5])
D = np.array([-0.5,0.5,-0.5])
E = np.array([-0.5,-0.5,0.5])
F = np.array([0.5,-0.5,0.5])
G = np.array([0.5,0.5,0.5])
H = np.array([-0.5,0.5,0.5])
load = np.array([A,B,C,D,E,F,G,H])
print(load)
fig = plt.figure()
ax = plt.axes(xlim =(-1,1),ylim =(-1,1))
# Declared to allow for x and y axis only
projection = np.array([ [1,0,0], [0,1,0] ])
xdata,ydata = [],[]
plt.title("Render 3D Cube in 2D Space")
for x in load:
for angle in range(360):
rotationY = np.array([ [np.cos(angle),0,np.sin(angle)],
[0,1,0],
[-np.sin(angle),0,np.cos(angle)] ])
rotationX = np.array([ [1,0,0],
[0,np.cos(angle),-np.sin(angle)],
[0,np.sin(angle),np.cos(angle)] ])
# Drawing each points
rotated = np.dot(rotationY,x)
rotated = np.dot(rotationX,rotated)
projected2d = np.dot(projection,rotated)
#projected2d = np.dot(projection,x) -With no rotations
line = ax.plot(projected2d[0],projected2d[1],c = "blue",marker = "o")
def animate(i):
x0,y0 = i
xdata.append(x0)
ydata.append(y0)
line.set_data(xdata,ydata)
return line
anim = FuncAnimation(fig,animate,interval =200,frames = 30)
plt.grid()
#plt.draw()
plt.show()
解决方案
FuncAnimation
构造函数采用一个可调用函数(在您的情况下),该函数animate
将当前帧号作为参数(此处i
)并更新绘图。这意味着,您应该将所有中间点存储在一个数组 ( frames
) 中,然后再访问它们(您也可以即时计算投影,但我不建议这样做)。然后动画将遍历帧并将函数应用于每一帧。
此外,您应该使用弧度(角度从 0 到 2π)进行旋转。
这是一个应该可以工作的版本:
# list of the angles in radians
angles = np.linspace(0, 2*np.pi, 360)
# storage of single frames - one value per point and angle.
frames = np.zeros((len(load),len(angles),2))
# loops through all points and angles to store for later usage.
for i, x in enumerate(load):
for j, angle in enumerate(angles):
rotationY = np.array([[np.cos(angle),0,np.sin(angle)],
[0,1,0],
[-np.sin(angle),0,np.cos(angle)] ])
rotationX = np.array([ [1,0,0],
[0,np.cos(angle),-np.sin(angle)],
[0,np.sin(angle),np.cos(angle)] ])
rotated = np.dot(rotationY, x)
rotated = np.dot(rotationX, rotated)
projected2d = np.dot(projection, rotated)
# store the point.
frames[i,j,:] = projected2d
# draws the initial point.
line, = ax.plot(frames[:,0,0], frames[:,0,1], c="blue", marker="o", ls='')
# defines what happens at frame 'i' - you want to update with the current
# frame that we have stored before.
def animate(i):
line.set_data(frames[:,i,0], frames[:,i,1])
return line # not really necessary, but optional for blit algorithm
# the number of frames is the number of angles that we wanted.
anim = FuncAnimation(fig, animate, interval=200, frames=len(angles))
推荐阅读
- powerbi - PBI DAX 查询前 N 个以返回文本
- python - 如何在 Python 中将两个不同的列合并为一列?
- workfront-api - Workfront API -> 如何从 workfront API 获取与项目关联的所有任务 ID?
- javascript - 错误:解析 with 表达式的主体时出错
- grep-indesign - 使用 InDesign GREP 选择字符后的文本
- gpu - 无法在 GKE 上使用一个 GPU 请求集群
- php - 是否可以在 Laravel 8 中的模型中放置复合键?
- c# - 控件是对象的观察者,我注册失败,因为尚未创建窗口句柄
- r - 缺少所有值时如何使用 min ?
- reactjs - 将 redux 与 Nextjs 一起使用,我不明白为什么它需要与 react 应用程序不同的更多设置