Very large Pix4D OrthoMosaic not importing in Autodesk Civil 3D

PIX4Dmapper PIX4Dmapper Questions/Troubleshooting
2

Hi Michael,

The tiles should be automatically generated in every project. I would recommend doublechecking the …\3_dsm_ortho\2_mosaic\tiles  folder and loading each individual tile in AutoCAD. 

Since the issue is related, as far as we know, to a single software (AutoCAD) and does not appear in other software (e.g. IrfanView, QSIG or Global Mapper.) we are currently not considering changing the way we are saving orthomosaics.

We dedicated our resources in order to better understand the issue and by processing several datasets concluded that the issue is most probably related to how AutoCAD handles large .tiff files. We did not experience any issues when importing results of smaller projects (smaller orthomosaics) but, on the other hand, faced the issue while importing results of larger projects (e.g. orthomosaics of more than 500 Mb).

To explain further:

  • AutoCAD does not handle very big files due to the size limitation. It might also depend on the version of the AutoCAD that you use, for example, we are facing the issue with AutoCAD 2017.

  • Moreover, we do not expect issues while importing the tiles or “smaller” orthomosaic (size of the file). For example, orthomosaic of 100mb should be fine. 

  • Pix4D always compresses the orthomosaic to LZW, however, the problem seems to be related to the BigTIFF file when the project is quite significant (large orthomosaic). AutoCAD probably does not know how to handle this BigTIFF variant and it results as if the orthomosaic was not LZW compressed. As a consequence, the large orthomosaic cannot be imported into AutoCAD. There are also other users reporting the issue and we kindly invite you to have a look and comment on the following post to get more insights: https://community.pix4d.com/t/2899

To import large orthomosaics into AutoCAD we recommend the following workflows:

  1. Load each tile of the orthomosaic one by one in AutoCAD.
  2. Use QGIS to save the orthomosaic since QGIS is able to read BigTIFF file. It will automatically convert the orthomosaic to a “more classic” LZW compression format. QGIS is an open source software and can be downloaded from here: http://www.qgis.org/en/site/forusers/download.html
  • Open QGIS.
  • Drag and drop the non-transparent orthomosaic generated by Pix4Dmapper.
  • Right-click on the corresponding layer and click Save As…
  • Once exported, drag and drop the new orthomosaic into the main view of AutoCAD.
  1. Use IrfanView:
  • Click File > Save as…
  • Save as Type: TIF 
  • On the TIFF save options window select LZW
  • Click Save. 
  • Open the LZW tiff file in AutoCAD.

Best,