Forum

Author Topic: question about DEM building and export in v1.2.1 from point cloud  (Read 2248 times)

andyroo

  • Sr. Member
  • ****
  • Posts: 439
    • View Profile
I am excited that now DEM and ortho are built and stored in PSX. It opens the way for cleaner products on export. But I am confused about how I can constrain DEM bounds when building in batch. It seems like I would want to be able to specify a  cell center (or corner) and size (like 1 cm, 2, cm, 10 cm 25 cm 50 cm, 1 m, etc), then that area of the dense cloud would be processed for each cell.

Previously (1.1.6 build 2038) I could specify custom extent and cell size to constrain bounds of DEM when exporting from TIN/mesh (for example integer extents when specifying custom area with integers and a cell size of 1 m), but if I am exporting a DEM with integer extents from a DEM with different cell size/boundary each time (each flight) it would have to interpolate from a different area of smaller DEM cells, and would result in reduced accuracy if I understand right.

I am trying to avoid having different cell bounds from flight to flight so I can better compare rough and sloped surfaces. My method to now has been to generate 500M poly meshes for each (~30 sq km) flight, and as above generate DEMs with integer bounds and meter or half-meter cells.

Andy

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 14837
    • View Profile
Re: question about DEM building and export in v1.2.1 from point cloud
« Reply #1 on: December 17, 2015, 01:08:31 PM »
Hello Andy,

If you are using Mesh as a source for the DEM generation you can change the resolution value in m/pix, whereas dense cloud based generation uses max. possible resolution. But you can always change the output resolution in the Export DEM dialog, as well as the export region (using region section in the Export DEM dialog or with the custom polygon-shapes set as boundary in the Ortho view).
Best regards,
Alexey Pasumansky,
Agisoft LLC