Orto from mesh settings

How does mech size and min futures affect ortophoto creation?

1 Like

--min-num-features generally will have an outsize impact on the completeness of the general reconstruction. Meaning, a larger total area by bounding polygon (typically), as well as a larger total area by point cloud coverage (typically).

By the above to main impacts, you would expect to see, in general, a larger, more complete orthophoto. Less holes generally means less reconstruction oddities in the ortho, as well.

--mesh-size mostly impacts the number of tris used to generate the mesh. The more tris you have, the more complex geometry within the scene can be adequately described and modeled. This should lead, in scenes with complex geometry, to an orthophoto with less “wobbly” bits or other texture wrapping issues.

All that being said, if you’re imaging a mostly flat area with all default parameters except for --min-num-features and --mesh-size, you likely won’t see a huge improvement by cranking those two up on their own. Combined with other parameters, however, it can be a huge difference.

Take these two comparisons:
Defaults:

Created on: 12/29/2021, 11:26:32 AM
Processing Node: node-odm-1 (manual)
Options: dsm: true
Average GSD: 1.61 cm
Area: 7,019.78 m²
Reconstructed Points: 813,075


Modified:

Created on: 12/29/2021, 11:37:31 AM
Processing Node: node-odm-1 (manual)
Options: auto-boundary: true, crop: 0, debug: true, dem-gapfill-steps: 4, dem-resolution: 0.1, dsm: true, dtm: true, feature-quality: ultra, matcher-neighbors: 0, matcher-type: bruteforce, mesh-octree-depth: 12, mesh-size: 5000000, min-num-features: 64000, orthophoto-resolution: 0.1, pc-classify: true, pc-filter: 1, pc-geometric: true, pc-quality: ultra, pc-rectify: true, pc-sample: 0.001, rerun-from: odm_meshing, resize-to: -1, use-3dmesh: true, verbose: true
Average GSD: 1.63 cm
Area: 7,059.6 m²
Reconstructed Points: 3,285,880

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.