ERROR Elevation Map and Surface Model TIFF

Hi everyone.
First of all thank you in advance for helping me on this project. I am new to WebODM and I am having some problems. After installing WebODM on MacOS Catalina 10.15.4 (19E266) I have noticed some errors.
I can upload the photos captured with the drone, execute the project and I get results: I can see the map in 2d (orthophoto, surface model and plant health) and 3d (point cloud and 3d model). When I try to generate the elevation map I get this error:

Could not execute GRASS script /webodm/plugins/elevationmap/ from / webodm / app / media / tmp / tmpv_7b7qdr_grass_engine: Starting GRASS GIS … Creating new GRASS GIS location … Cleaning up temporary files … . Executing <python /webodm/plugins/elevationmap/ dsm = / webodm / app / media / project / 1 / task / df90f109-6d84-4e7e-9f8a-c708ac95ba22 / assets / odm_dem / dsm.tif interval = 5 format = GeoJSON noise_filter_size = 0.0 epsg = 4326> … Traceback (most recent call last): File “/webodm/plugins/elevationmap/”, line 48, in import cv2, math, argparse ModuleNotFoundError: No module named ‘cv2’ Execution of <python /webodm/plugins/elevationmap/ dsm = / webodm / app / media / project / 1 / task / df90f109-6d84-4e7e-9f8a-c708ac95ba22 / assets / odm_dem / dsm. tif interval = 5 format = GeoJSON noise_filter_size = 0.0 epsg = 4326> finished. Cleaning up temporary files …
It seems a module “ModuleNotFoundError: No module named ‘cv2’” is missing

Another problem I have when trying to export the surface model in GeoTIFF, which appears all blank.
I hope you can help me with these problems. Thank you very much.

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Hey Antonio, and welcome.

From the error message you’ve quoted above, it would appear that there is at least one dependency issue that is causing the elevation process to fail, which would appear to be the python module cv2:

I still struggle with trying to establish an environment manually, so I’m not sure the best approach at this point.

I would recommend trying to install OpenCV-python into your python environment using pip:
pip install OpenCV-python

Mm, are you running the latest version of WebODM? When did you last update it?

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I´m using App Version: 1.3.4. Is that ok?

Thanks for you help Saijin. Where exacly do i need to used this command? (pip install OpenCV-python)

I open mac terminal and use:
first “python”
then “pip install OpenCV-python”
and this is what i get:

WARNING: Python 2.7 is not recommended.

This version is included in macOS for compatibility with legacy software.

Future versions of macOS will not include Python 2.7.

Instead, it is recommended that you transition to using ‘python3’ from within Terminal.

Python 2.7.16 (default, Feb 29 2020, 01:55:37)

[GCC 4.2.1 Compatible Apple LLVM 11.0.3 (clang-1103.0.29.20) (-macos10.15-objc- on darwin

Type “help”, “copyright”, “credits” or “license” for more information.

pip install OpenCV-python

File “”, line 1

pip install OpenCV-python

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What does this return?
python3 -m pip install opencv-python

Try to enable/disable the plugin, then restart WebODM with the appropriate command.

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This is what a get when i write

python3 -m pip install opencv-python

in the terminal

Requirement already satisfied: opencv-python in /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages (

Requirement already satisfied: numpy>=1.17.3 in /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages (from opencv-python) (1.18.2)

WARNING: You are using pip version 19.2.3, however version 20.0.2 is available.

You should consider upgrading via the ‘pip install --upgrade pip’ command.

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Thank you Piero.
Do you mean elevation map plugin right? So i first disable, then enable again, and then restart WebODM with a command (./ restart) ? in the terminal right?

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Thank you very much guys!

Following your help, finally it works.
What i did first was an WebODM update using command ‘./ update’ in the mac terminal
Then i restart WebODM using the command ‘./ restart’

My other problem was exporting (Download assets) Surface Model (GeoTIFF and Tiles).
What i get from these exports is a GeoTIFF, that is blank, (it is NOT blank when i export an Ortophoto GeoTIFF) and a .zip archive with lots of folders from Tiles export.
Probably there is a way to put all together and get a full surface model. Maybe you can tell me how? I really appreciate your help. Thanks :slight_smile:


Make sure you are opening the GeoTIFF in a program such as QGIS.


Great . Thanks
Now i need to learn how to use all of this.


Baby steps! Don’t get overwhelmed, as the first start experience in QGIS can be button and toolbar overload.

QGIS is a huge, powerful suite. I’m a GIS Analyst and I still have tons to learn in QGIS. You’ll get where you need to be.

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