How does SelectionPolygonVolume work?

[guhur]

Hi,

I am surprised by the following result:

points = np.array([[-0.37841943, -0.05783039,  2.42544341],
       [-0.72100592,  0.5099898 ,  1.67696834],
       [ 0.13754743,  1.0226984 ,  1.67295718],
       [ 0.48013398,  0.45487815,  2.42143226],
       [ 0.26103601, -0.16154499,  1.38604999]])
pcd = o3d.geometry.PointCloud()
pcd.points = o3d.utility.Vector3dVector(points)
print(pcd)

selector = open3d.visualization.SelectionPolygonVolume()
selector.bounding_polygon = o3d.utility.Vector3dVector(points)

selected = selector.crop_point_cloud(pcd)
print(selected)

It prints:

PointCloud with 5 points.
PointCloud with 0 points.

So basically, cropping a Point Cloud with itself returns nothing (!?)

Can you enlighten me about it is going on?

[mserouar]

Same there, including after .astype("float64") tranformation.

The fact is that you need to specify what axis to orient the polygon vertices to.

Here for example the "X" axis.

vol.axis_max = np.max(bounding_polygon[:, 0])
vol.axis_min = np.min(bounding_polygon[:, 0])

[veenusav]

vol = o3d.visualization.SelectionPolygonVolume()
vol.orthogonal_axis = "Z"
vol.axis_min = -2000
vol.axis_max = 4000
vol.bounding_polygon =  o3d.utility.Vector3dVector(points)
cropped = vol.crop_point_cloud(pcd)

the above kind of code worked.