Spot Elevations in my Pix4D Matic model are different than the spot elevations in the surface I create in AutoCAD Civil3D using the contours exported from the same Pix4D Matic Model

PIX4Dmatic
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Any suggestions for trouble shooting this issue? Both Civil 3D and my Pix4D model are using the exact same coordinate system, units etc… I have uploaded an image with my processing and survey settings. This is the process I follow. I process Calibration, then Dense Point Cloud then DSM, Orthomosaic and Mesh all at once. Once that is complete I create the contour lines using teh following:

Terrain Classification, Grid of Points, TIN, DTM, Contour lines.

I then go to file, export, contour lines, zip shp. Then I extract the zip file. I open Civil 3D. Perform the MAPIMPORT command to bring in the contour poylines and choose the SHP file.

My spot elevations on my surface in Civil 3D created from the contour lines is 6 to 15 feet off compared to the pix4d Matic Model whose values are more accurate tor real world values.

Any help is appreciated.

Thank You.

Processing and Survery Settings.pdf (139.0 KB)