Agisoft Metashape

Agisoft Metashape => General => Topic started by: suicamari on November 08, 2021, 10:03:40 PM

Title: DTM without Mesh
Post by: suicamari on November 08, 2021, 10:03:40 PM

Hi guys, I have a question!

I understand that the difference between DSM and DTM is that, when creating DSM, all classes are used, and when creating DTM, only ground is used.

Do I really need to create mesh to create DTM? Could I go straight to "Build DEM", select only "ground" and obtain DTM, using only the dense cloud point as source?

Thank you

Title: Re: DTM without Mesh
Post by: Alexey Pasumansky on November 10, 2021, 04:18:50 PM

Hello suicamari,

If you need to use only certain classes of the dense point cloud for the elevation model reconstruction, you should use Build DEM command and select the desired classes.

Alternatively, you can build mesh from the selected classes and use Build DEM with the mesh source option, but I don't see any practical benefit for the general cases, following this approach. Usually using dense cloud source for the Build DEM operation is recommended.

Title: Re: DTM without Mesh
Post by: PROBERT1968 on November 14, 2021, 05:17:24 PM

Like what Alexy mention to you but might be better for you to understand the difference between the DSM and DTM.  I have google for that for you to help you clear better

https://www.google.com/search?q=Examples+between+DSM+and+DTM&sxsrf=AOaemvJVWDiBR2ONqqOMLSc-dvLcH6NKkg:1636899103391&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiWttyshJj0AhU7kmoFHfoUCwoQ_AUoAnoECAEQBA&biw=1920&bih=880&dpr=1


for more in details , I found this one from a journal     https://www.mdpi.com/2072-4292/13/18/3581/htm

I took LIDAR course through my work and I understand how it works .