Inconsistency with cc.loadPointCloud()

[adjablonski]

Update

Upon further testing, I was able to run cc.launchTests() and cc.launchCloudCompareGUI() with no issue. I then tried to load my data files (.las file format) using cc.loadPointCloud(), but it still did not work correctly and returned none. Thinking it could be a pathing issue, I then tried to load the example datasets created from the tests.

cloud  = cc.loadPointCloud('.../CloudComPY/Data/cloudCropX.xyz')
cloud2 = cc.loadPointCloud('.../CloudComPY/Data/cloud.las')
print(type(cloud))
print(type(cloud2))
<class '_cloudComPy.ccPointCloud'>
<class 'NoneType'>

cc.loadPointCloud() has no problem loading the example data crated from the tests when it is a .xyz file format. But it is unable to load the .las example file that was created. Again, there appears to be some inconsistency here as I was able to load .las files using this function the other day, but I have no way of troubleshooting why/when it fails.

Edit: After doing more tests, the following file formats do not load with cc.loadPointCloud() - .las .laz .pcd .ptx

Original post

Hi,

I am using pixi (https://pixi.prefix.dev/latest/) to build a Python environment that can run CloudComPy on a Windows 11 machine. I have CloudCompare v2.14beta installed on my computer, and am using the latest binaries (CloudComPy312_20260610). I am running into an issue where on some occasions, CloudComPy does not appear to be working. For instance, I will try to run cc.loadPointCloud() and the function runs with no errors, but doesn't actually load the file and returns nothing. More frustrating is that I have not found a reliable way to troubleshoot why this happens - the test script I was building yesterday was functioning fine, but today nothing is working. I'm not sure if this is a problem with my installation or setup, but if there are any thoughts/suggestions on how to troubleshoot that would great.

Here are some simple diagnostics I can show:

Running envCloudComPy shows no issues:

(Python:dev) ...\CloudComPy312>envCloudComPy.bat
Checking environment, Python test: import cloudComPy
...\CloudComPy312\CloudCompare\cloudComPy
...\CloudComPy312\CloudCompare
...\CloudComPy312\CloudCompare\plugins
Environment OK!

Importing cc in python does return the following error which seems to be related to no QCoreApplication instance being started. I think this could be related to my issue, but the same error also appears on import when it is working normally, so I'm not sure.

import cloudComPy as cc 
QFileSystemWatcher: Removable drive notification will not work if there is no QCoreApplication instance.
...\CloudComPy312\CloudCompare\cloudComPy
...\CloudComPy312\CloudCompare
...\CloudComPy312\CloudCompare\plugins

cc.launchDoc() works just fine, so the issue seems to be related to actually running/instancing CloudCompare. I'm also attaching my pyproject.toml file, so in theory someone should be able to replicate this exact environment/build.

[project]
dependencies = ["numpy-groupies>=0.11.3,<0.12", "numpy-quaternion>=2024.0.13,<2025", "lxml-html-clean>=0.4.5,<0.5"]
name = "Python"
requires-python = ">= 3.11"
version = "0.1.0"

[build-system]
build-backend = "hatchling.build"
requires = ["hatchling"]

[tool.pixi.workspace]
channels = ["conda-forge"]
platforms = [{platform = "win-64", cuda = "13.0"}]

[tool.pixi.pypi-dependencies]
python = { path = ".", editable = true }

[tool.pixi.tasks]

[tool.pixi.dependencies]
pytorch-gpu = ">=2.12.1,<3"
numpy = "1.26.*"
scikit-image = "0.22.0.*"
scikit-learn = ">=1.9.0,<2"
circle-fit = ">=0.1.3,<0.2"
timm = ">=1.0.27,<2"
numpy-indexed = ">=0.3.7,<0.4"
matplotlib = ">=3.11.0,<4"
cmake = ">=4.3.4,<5"
requests = ">=2.34.2,<3"
psutil = ">=7.2.2,<8"

[tool.pixi.feature.dev.dependencies]
spyder = ">=6.1.5,<7"

[tool.pixi.environments]
default = { solve-group = "default" }
dev = { features = ["dev"], solve-group = "default" }

[prascle]

Hello,
Sorry for the slightly delayed response.

The messages you see in your first post are completely normal, especially the message “QFileSystemWatcher: Removable drive notification will not work if there is no QCoreApplication instance.” That message is generated by Qt; I didn't try to hide it.

What you’re seeing has me puzzled. If you’re able to run the tests with cc.launchTests(), that means cloudComPy is able to read the LAS files from my tests; otherwise, for example, test003.py would fail.
I set up the environment you suggested using pyproject.toml, and all the tests passed. I ran the test003.py test separately. I successfully tested loading las and laz files in CloudCompare.
Since the behavior seems random, it would be helpful if you could describe very precisely a scenario that occasionally leads to an error. On Windows, for example, there can be DLL conflict issues that are difficult to diagnose or fix. This will depend on the environment’s packages, if you modify them. There could also be issues with PATH or PYTHONPATH that might cause problems depending on the method used to load the environment and run the Python script...
You can also try using the basic PYPI environment I suggest on the download page for testing to see if you can reproduce the issues...

Regards,
Paul

[adjablonski]

Thanks for the response Paul!

I've done so more troubleshooting, and I believe I can isolate the issue on my machine. It must be related to issues with the path. I import cloudComPy at the start of my scripts with the following lines:

import os, sys

sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\CloudCompare\\')
sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\')
sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\CloudCompare\\cloudComPy\\')

import cloudComPy as cc

I was testing things out via the command line and activating my environment, and replicated the same result from the following commands:

cd Documents/LeafWoodClass/Python
pixi shell
cd ../CloudComPy312
python

Then in python, I entered the same lines and had the same issue.

import os,sys

sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\CloudCompare\\')
sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\')
sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\CloudCompare\\cloudComPy\\')

import cloudComPy as cc
cloud2 = cc.loadPointCloud('C:/Users/andrewjablonski/CloudComPY/Data/cloud.las')
type(cloud2)
<class 'NoneType'>

However, if I run envCloudComPy.bat first while my environment is activated, everything works fine.

cd Documents/LeafWoodClass/Python
pixi shell
cd ../CloudComPy312
envCloudComPy.bat
Checking environment, Python test: import cloudComPy
C:\Users\andrewjablonski\Documents\LeafWoodClass\CloudComPy312\CloudCompare\cloudComPy
C:\Users\andrewjablonski\Documents\LeafWoodClass\CloudComPy312\CloudCompare
C:\Users\andrewjablonski\Documents\LeafWoodClass\CloudComPy312\CloudCompare\plugins
Environment OK!
python

Doing this allows the .las file to be read with no issue.

import os,sys

sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\CloudCompare\\')
sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\')
sys.path.insert(0, 'C:\\Users\\andrewjablonski\\Documents\\LeafWoodClass' + '\\CloudComPy312\\CloudCompare\\cloudComPy\\')

import cloudComPy as cc
cloud2 = cc.loadPointCloud('C:/Users/andrewjablonski/CloudComPY/Data/cloud.las')
type(cloud2)
<class '_cloudComPy.ccPointCloud'>

So my current solution is to just run envCloudComPy.bat while my environment is activated, and then run Spyder. Doing this allows everything to work seemingly as intended (I haven't encountered any new issues yet). I'm not sure if there is a way to simplify this even further, but if not this is not too much of a hassle.

[prascle]

Hello,

The envCloudComPy.bat file sets the PYTHONPATH variable (to locate the cloudComPy Python module) and the PATH variable (to locate the cloudComPy and CloudCompare libraries and executables). You must perform this step in one way or another. You can try setting the PATH from within Python by modifying os.environ[“PATH”] before importing cloudComPy. Refer to the envCloudComPy.bat file to see which values to set. If you always use Spyder, you can configure these variables from the menus.

Regards,
Paul