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DTM output as a grid

Civil 3d behaves much better with a gridded definition of the surface. I can open a DSM grid in seconds.

 Now, I use the raster DTM as surface definition in Civil3d (time consuming process) and then have the surface simplified as a grid.  Then I use the grid definition for the final surface.  It would be nice if Pix4d could create the DTM grid for input into Civil3d like is does for the DSM.


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Hi William,


Thank you for your input. We understand your point!
I have added your idea to our Suggestion List. Our Product Development Team will consider it for future version of the software. 


Have a nice day,


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Any up dates on this?



Hi Ernesto,

Unfortunately, still it is not possible to export the grid DTM from Pix4D Desktop. However, there is a workaround that can give you this output.

To get the grid DTM of an area you should edit the point cloud so that you assign to the Disabled point group all the points that are not terrain points. Then, you should rerun step 3 to generate the new DSM and grid DSM, which in reality will correspond to the DTM of the area.

Please note that this process requires some manual work and depending on the size of the project can be quite time-consuming. 


Do you know if another work around could be to take the DTM tiff file and create a grid with another software like Civil 3D?

Hello Ernesto,

I have no experience with the process of generating a grid surface in other software.
After a quick search online I found this page from the Knowledge Base of Autodesk. I have not tested it though and I cannot guarantee that this is the correct workflow. Maybe you could contact the Autodesk support for more information.



William Miller: 

Any chance you could describe the process for getting the raster DTM into Civil3D, and then simplify as a grid?

I have been trying to provide/find a solution for our drafter on how to get the dtm.tiff file to show. As the DSM grid file is not accurate enough for the current job.

Any help is appreciated!

After much heartache, gnashing of teeth and hair pulling, we have come up with the following work around to dealing with the grid and the volume of points produced.

We choose a contour line interval of 0.25’ and save the contours as a dxf file. Then we just open a new drawing, import the contour lines and use them to create a new surface.  Then we just cut and paste the surface only into the drawing we created for our project.  Once we have the surface we can choose any contour interval we want.  

My logic is that the small contour interval picks up all of the irregularities in the surface no matter what the grid density used.  I believe it to be a much better way to transfer the data.  We have field checked dozens of surfaces and generally find the accuracy to be under 0.10’.  A grid does not do well with curb and gutter details.  My method picks up every small change in elevation.  We have tried using an even smaller contour interval but I don’t believe it really helps the surface any.

Our only headache has been the overlap between drone flights.  We shoot a lot of roadways for topography.  We use a lot of GCP (250’ interval pairs) and try for at least 500’ of overlap.  We usually fly and process in about 4000’ segments with 500’ of overlap.  We then try to find the best fit of the contour lines that match between flights and trim each contour and surface to match. Then we just combine it into one large surface.

Hope this helps.

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Nice William!