Coverage for src/evutils/vis/open3d.py: 46%

1"""Open3D visualization utilities for event camera data. 

2 

3This module provides functions to visualize event streams in 3D (x, y, time) 

4using Open3D. 

5 

6``open3d`` and ``matplotlib`` are imported lazily, inside the functions that 

7use them, so importing this module stays cheap. 

8""" 

9import numpy as np 

10 

11def o3d_draw_events(events: np.ndarray) -> None: 

12 """Visualizes events using Open3D. 

13 

14 Parameters 

15 ---------- 

16 events : np.ndarray 

17 Array of events with fields 'x', 'y', 't', and 'p'. 

18 'x' and 'y' are the pixel coordinates, 't' is the timestamp, and 'p' is the polarity. 

19 

20 Returns 

21 ------- 

22 None 

23 

24 """ 

25 import open3d as o3d 

26 from matplotlib import pyplot as plt 

27 

28 if len(events) == 0: 

29 return 

30 

31 # Draw X, Y, T as a pointcloud 

32 pdc = o3d.geometry.PointCloud() 

33 

34 time_diff = np.max(events['t']) - np.min(events['t']) 

35 # Normalize time to range 0..3000 

36 norm_time = (events['t'] - np.min(events['t'])) / time_diff * 3000 

37 

38 pdc.points = o3d.utility.Vector3dVector(np.column_stack((events['x'], events['y'], norm_time))) 

39 

40 # Create a color map based on the 'p' 

41 # p can be either 0 or 1, we use it to color the points witht eh Spectral colormap 

42 colors = plt.cm.Spectral(events['p'].astype(np.float32))[:, :3] # Use only RGB channels 

43 

44 pdc.colors = o3d.utility.Vector3dVector(colors) 

45 

46 o3d.visualization.draw_geometries([pdc])