Get lowest points of 4 Point Clouds

[broesmeli]

Hey there!
I have 4 PointClouds of the same area from different dates. Its an excavation site that is under constant construction, so material is put in and out constantly. Thats why i took different Clouds to compare those.

My question:
How can i get all the lowest points from those 4 Clouds and generate a new point cloud out of them?
I already merged them but i dont know how to filter for the lowest points...

Thanks in advance!

[daniel]

The easiest way is probably to use the 'Rasterize' tool and keep the 'minimum' height inside each cell (and keep the 'Resample input cloud' option checked so that your points are not modified).