I think the conda-approach could work, but then you might need to install all the modules that come with Python+FME, to not run into issues. I think that's why the encoding-import fails - but even installing it the "right" FME-way, I couldn't get it to load either - I'll try some more stuff!

EDIT:

When I run fme.exe python from cmd (to get the python interpreter that FME will use, good for debugging), and then write import pyntcloud, I get this error: 

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\mywindowsaccount\Documents\FME\Plugins\Python\pyntcloud\__init__.py", line 1, in <module>
    from .core_class import PyntCloud
  File "C:\Users\mywindowsaccount\Documents\FME\Plugins\Python\pyntcloud\core_class.py", line 6, in <module>
    from .structures.base import StructuresDict
  File "C:\Users\mywindowsaccount\Documents\FME\Plugins\Python\pyntcloud\structures\__init__.py", line 4, in <module>
    from .convex_hull import ConvexHull
  File "C:\Users\mywindowsaccount\Documents\FME\Plugins\Python\pyntcloud\structures\convex_hull.py", line 2, in <module>
    from scipy.spatial import ConvexHull as scipy_ConvexHull
  File "C:\Users\mywindowsaccount\Documents\FME\Plugins\Python\scipy\__init__.py", line 104, in <module>
    from . import _distributor_init
  File "C:\Users\mywindowsaccount\Documents\FME\Plugins\Python\scipy\_distributor_init.py", line 61, in <module>
    WinDLL(os.path.abspath(filename))
  File "D:\obj\windows-release\37amd64_Release\msi_python\zip_amd64\__init__.py", line 364, in __init__
OSError: &WinError 126] The specified module could not be found

So, something in some underlying project hasn't gone well. scipy seems to be the issue, since it points to a path that absolutely doesn't exist. 

@fhilding Thank you for your answer. I posted this issue at the GitHub repo of pyntcloud.

@david_r I have seen your comment here. Would you mind to give some hints why conda environment is not cooperating? :)

I haven't used conda much, and not with venvs, but have you already looked at this post?

https://knowledge.safe.com/questions/83789/configuring-anaconda-environment-in-fme.html

While I haven't tested anything specifically with this package, from recent Python experiments in FME I did find that sometimes you get package conflicts. If pyntcloud depends on a library that FME already uses you might have a version conflict.

Try importing all the dependencies and print their module.__version__ then compare between your venv result and FME. If it is different you can play silly games with temporary changes to sys.path to get around it.

Thanks Guys (@fhilding @david_r @jstanger) for those answers! I have found a solution!

However, I would like to give some hints by explaining my steps for solving the problem:

1. Pyntcloud does not work with Python 3.7 properly and indeed scipy cause some problems. I have opened the ticket at the GitHub repo.
2. ...but it does work with Python 3.6! Therefore, I have created a virtual environment within conda and set up it as Custom Interpreter (see @david_r link) . The environment triggered but the package not as somehow FME was still looking within main packages of conda, not within my virtual environment.
3. So, I have figured out a different approach. I have downloaded standard Python 3.6 and used pip to install pyntcloud. Then pointed out to this Python in the FME configuration (here, double-check whether PYTHONHOME, PYTHONPATH and Path point out to the same Python directory in your Windows variables). Now... it is working!

Nice job with the fastidious debugging, @oloocki!