[Qgis-user] Assistance Required for Creating Watertight 3D Map Geometry Using QGIS

[Tobias Schula]

On Tuesday, 4 March 2025, 05:41:04 CET Harnish Patel via QGIS-User wrote:
> I hope this message finds you well. I am currently working on an airflow
> simulation project using Ansys Fluent, where I aim to simulate airflow
> dynamics through an urban city area. To proceed with the simulation, I
> require a 3D watertight geometry of the city to input into the simulation
> software.

You can create a mesh from DEM data and buildings in QGIS, but the exported 
mesh will hardly be watertight. I suggest you export it to a 3D modeling 
software like blender. 

You can use the plugin "Qgis2threejs", it will export into glTF which you can 
import in blender:
> https://plugins.qgis.org/plugins/Qgis2threejs/#plugin-details

Also read the documentation:
>https://minorua.github.io/Qgis2threejs/docs/

Then consult the blender documentation and community for making your mesh 
watertight. Unfortunately, my knowledge of Blender is constricted to modeling 
for 3D games and that was 15 years ago.

Best regards
Toby
-- 
Tobias A Schula
Forestry Expert

geospatial at schula.org