How to decimate planar faces of the house based on mesh from LIDAR point cloud data?

Hi, maybe you could help me somehow with a hint…
My aim is to recreate building and ground structure based on LIDAR point cloud data to very very simple house models. I am able to create a mesh model (with some ugly artefacts on the edges - but I know I can smooth them) with a thousands of faces. But I’d like to have 10-20-30-50 faces depending on house.
How to do it in the easiest way? As I am aiming in big regions so that redrawing all of the houses is impossible.
I guess it will be something to do with smooth, and decimate modifiers, but maybe there is another, easier way?
I need to do it for few thousand buildings of different shape…

I attach image with some explenations

will be glad for any suggestions!

see these

meshroom might have more tool to help decimate points clouds
but not certain how you auto deal with 1000 of buildings !

if you find a better way let us know

happy bl

i found these too
so have a look if you can find some faster way

LIDAR

happy bl

Is there any chance you could share one point cloud example with us?
I think you might have better luck with something like meshlab

right it is meshlab not meshroom

sorry my bad!

should offer more tools for points cloud

happy bl

Sure, i did try it in Meshlab with some marshing cubes algorythms and Poisson, as well as in cloud compare with some RANSAC functions, but I feel like I miss a step… I attach LAS file (photogrammetric - not LIDAR), saved as PLY file that could be opened in meshlab without problems. (and raw las file(zipped) as well)example.ply (3.3 MB) example.zip (3.4 MB)

Well, this is surprisingly difficult.
I tried some stuff in Meshlab, but I’ve only had mediocre results.


I did find this project, someone implemented what you’re trying to do (I think) in Unity, which you could try out. Their input looks a lot like your, so it might be worth a try. You just have to extrude the roofs downwards to create walls.

Thanks! I didn’t find that one before!
It is exactly the problem I am trying to solve.
Will give it a try!

hi @Lynx86 :slight_smile:

Could you please trell me where you got such accurate point cloud ?

I guess the ground elevation model can also be as accurate as this ?

This is quite interresting to me as on the web i only found 15x15m resolution for ground elevation data…

Thanks in advance and happy blending ! :slight_smile:

Glad to hear, @ me if you make it work :slight_smile:

It all depends :slight_smile:
There are some open repositories with LAS (Lidar data files) that could be even more accurate. Both for terrain, buildings or some objects.
Data I am working with right now are obtained with processing of drone images. It could be done with both commercial and open software. I started my adventure with that YT film, and then did some tries with bigger objects than in the film. Results could be in a really good quality - like that (Church in Poland or the other one). You could create 3D mesh models from that images as well. Problem is that they could be far too detailed, that could influence the processing and rendering speed (same church as 3D model ) (files in links are possible to download - feel free to play with them :slight_smile:
That file I am working with now is created also with drone images taken by my colleagues. They did take only images from top (not many with other angle) so thats why it has not complete facade.

EDIT: try links from here: https://gisgeography.com/top-6-free-lidar-data-sources/

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