Open3d: Crop point cloud

[oarriaga]

In the documentation website it says:

read_selection_polygon_volume reads a json file that specifies polygon selection area.
vol = read_selection_polygon_volume("../../TestData/Crop/cropped.json")

But the contents of the json file are never specified. How does the json file should look like?

[adioshun]

I also looking for a pointcloud cropping method.

I found this :https://github.com/IntelVCL/Open3D/blob/master/src/Test/TestData/Crop/cropped.json

{
    "axis_max" : 4.022921085357666,
    "axis_min" : -0.76341366767883301,
    "bounding_polygon" : 
    [
        [ 2.6509309513852526, 0.0, 1.6834473132326844 ],
        [ 2.5786428246917148, 0.0, 1.6892074266735244 ],
        [ 2.4625790337552154, 0.0, 1.6665777078297999 ],
        [ 2.2228544982251655, 0.0, 1.6168160446813649 ],
        [ 2.166993206001413, 0.0, 1.6115495157201662 ],
        [ 2.1167895865303286, 0.0, 1.6257706054969348 ],
        [ 2.0634657721747383, 0.0, 1.623021658624539 ],
        [ 2.0568612343437236, 0.0, 1.5853892911207643 ],
        [ 2.1605399001237027, 0.0, 0.96228993255083017 ],
        [ 2.1956669387205228, 0.0, 0.95572746049785073 ],
        [ 2.2191318790575583, 0.0, 0.88734449982108754 ],
        [ 2.2484881847925919, 0.0, 0.87042807267013633 ],
        [ 2.6891234157295827, 0.0, 0.94140677988967603 ],
        [ 2.7328692490470647, 0.0, 0.98775740674840251 ],
        [ 2.7129337547575547, 0.0, 1.0398850034649203 ],
        [ 2.7592174072415405, 0.0, 1.0692940558509485 ],
        [ 2.7689216419453428, 0.0, 1.0953914441371593 ],
        [ 2.6851455625455669, 0.0, 1.6307334122162018 ],
        [ 2.6714776099981239, 0.0, 1.675524657088997 ],
        [ 2.6579576128816544, 0.0, 1.6819127849749496 ]
    ],
    "class_name" : "SelectionPolygonVolume",
    "orthogonal_axis" : "Y",
    "version_major" : 1,
    "version_minor" : 0
}

However, It looks for the polygon format. I didn't check it for point cloud data.

[qianyizh]

Yes. This is the polygon format. You can create one from a GUI: bin/ManuallyCropPointCloud

[SreenivasVRao]

Sorry, but where is this file located? I installed Open3D with conda+pip but I can't find this binary.

Also, when I use draw_geometries_with_editing and crop the cloud, the json file has a null polygon.

{
"axis_max" : 0,
"axis_min" : 0,
"bounding_polygon" : null,
"class_name" : "SelectionPolygonVolume",
"orthogonal_axis" : "",
"version_major" : 1,
"version_minor" : 0
}

[kimwubin]

@SreenivasVRao The viewer must be aligned to an orthogonal_axis (by pressing x, y or z). This prevents the null values in the json. It would be nice to have this printed in the help.

[noscript]

Any idea how to do the invert crop, e.g. remove points inside a volume?

[IvanCobotic]

Any idea how to do the invert crop, e.g. remove points inside a volume?

I´m also looking for this feature