Matplotlib绘制的3D载具轨迹动画无动态效果，求解决

我有一个形状为(18,101)的数组X_trj，用于绘制3辆不同载具的3D轨迹，尝试用以下代码实现动画，但运行后得到静态轨迹图，生成的animation.mp4也没有动态效果：

#animate the plot:
import matplotlib.animation as animation

# First, create a function that updates the scatter plot for each frame
def update_plot(n,X_trj,scatters):
    # Set the data for each scatter plot
    scatters[0].set_offsets(np.stack((X_trj[0, :n], X_trj[1, :n], X_trj[2, :n]), axis=1))
    scatters[1].set_offsets(np.stack((X_trj[6, :n], X_trj[7, :n], X_trj[8, :n]), axis=1))
    scatters[2].set_offsets(np.stack((X_trj[12,:n], X_trj[13, :n], X_trj[14,:n]), axis=1))
    return scatters


# Create the figure and axis
fig = plt.figure()
ax = plt.axes(projection='3d')

# Create the scatter plots
scatters = []
scatters.append(ax.scatter(X_trj[0,:], X_trj[1,:], X_trj[2,:]))
scatters.append(ax.scatter(X_trj[6,:], X_trj[7,:], X_trj[8,:]))
scatters.append(ax.scatter(X_trj[12,:], X_trj[13,:], X_trj[14,:]))

# Set the title
ax.set_title('Trajectory from one-shot optimization (human + drones)')

ani = animation.FuncAnimation(fig, update_plot, frames=range(X_trj.shape[1]), fargs=(X_trj, scatters))

plt.show()
ani.save('animation.mp4')

问题原因 #

1. 3D散点更新方法错误：set_offsets()是专门给2D散点图设计的更新接口，3D场景下必须使用set_offsets3d()来更新三维坐标数据。
2. 初始绘制了全部轨迹：初始化散点时直接渲染了所有帧的轨迹点，后续帧更新无法体现轨迹逐步生成的动态变化。

修改后的完整代码 #

import matplotlib.pyplot as plt
import matplotlib.animation as animation
import numpy as np

# 逐帧更新3D散点数据
def update_plot(n, X_trj, scatters):
    # 用set_offsets3d更新三维坐标
    scatters[0].set_offsets3d((X_trj[0, :n], X_trj[1, :n], X_trj[2, :n]))
    scatters[1].set_offsets3d((X_trj[6, :n], X_trj[7, :n], X_trj[8, :n]))
    scatters[2].set_offsets3d((X_trj[12,:n], X_trj[13, :n], X_trj[14,:n]))
    return scatters

# 创建画布与3D坐标轴
fig = plt.figure()
ax = plt.axes(projection='3d')

# 初始化散点：只绘制第一个点，避免初始显示全部轨迹
scatters = []
scatters.append(ax.scatter(X_trj[0, :1], X_trj[1, :1], X_trj[2, :1]))
scatters.append(ax.scatter(X_trj[6, :1], X_trj[7, :1], X_trj[8, :1]))
scatters.append(ax.scatter(X_trj[12, :1], X_trj[13, :1], X_trj[14, :1]))

# 设置图表属性
ax.set_title('Trajectory from one-shot optimization (human + drones)')
ax.set_xlabel('X Axis')
ax.set_ylabel('Y Axis')
ax.set_zlabel('Z Axis')

# 创建动画：从第1帧开始（n=0无数据），设置帧间隔控制速度
ani = animation.FuncAnimation(
    fig,
    update_plot,
    frames=range(1, X_trj.shape[1]),
    fargs=(X_trj, scatters),
    interval=50  # 每帧间隔50毫秒，数值越小动画越快
)

plt.show()
# 保存视频需确保已安装ffmpeg，可通过pip install ffmpeg-python安装
ani.save('animation.mp4', writer='ffmpeg')

额外说明 #

• 保存视频前需确保环境已安装ffmpeg，否则会报错。
• interval参数可按需调整，控制动画播放速度。

内容的提问来源于stack exchange，提问作者Randy Chen