Allow custom resolution for DEM generation

[Erik Holmlund]

Dear Agisoft team,

Metashape currently offers almost every feature that one can ask for in the process of deriving DEMs from images! One feature that I sorely miss, however, is specifying a custom grid (resolution and bounds) of the output DEM. Currently, my workflow requires me to export the dense cloud and grid it in PDAL – a process which is time consuming and unwieldy.

I request the resolution field to be changeable in the Build DEM step for dense clouds, exactly like is already possible when building DEMs from meshes.

Thank you in advance.

Kind regards,
Erik

[Alexey Pasumansky]

Hello Erik,

You can use Transform DEM option to make a copy of original DEM in custom user-defined resolution.

As for the custom export bounds, you can draw a polygonal shape in Ortho view, assign Outer Boundary type to it and in the Export DEM dialog enable "clip to boundary shapes" option.

[Erik Holmlund]

Hi Alexey,
Thank you for the quick answer.

The transform DEM tool naturally works well to resample a DEM. However, this may yield sub-optimal results at times.

Imagine I have a noisy point cloud where the "Metashape DEM resolution" is high (let's say 0.5 m). This may work well, but will yield lots of nodata-pixels. If Transform DEM is used to a target resolution (e.g. 5m), the nodata-pixels are propagated to the entire new pixel and will result in a poor DEM. A much better approach (which is easy with other tools, such as PDAL, GDAL or CloudCompare) is to specify a coarser gridding resolution (5m), which will not have the same propagating nodata issue.


Erik