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Author Topic: DEM is clipped to smaller extent than orthomosaic  (Read 2746 times)

mguy

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DEM is clipped to smaller extent than orthomosaic
« on: November 17, 2016, 04:42:59 AM »
Hi,

I was able to generate a dense point cloud and export an orthomosaic that covers the full extent of the images I collected. However, when I try to generate a DEM, it only covers a small portion of the total extent. The bounding box is not changed. I am using GCP's but not photo coordinates. I attached a screen shot of the ortho and the dem. Thank you for any help you can provide!

Alexey Pasumansky

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Re: DEM is clipped to smaller extent than orthomosaic
« Reply #1 on: November 17, 2016, 02:43:34 PM »
Hello mguycooper.

What source you are using for DEM and Orthomosaic generation? Please check that the source used for DEM (dense cloud or mesh) is not cropped.
Best regards,
Alexey Pasumansky,
Agisoft LLC

mguy

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Re: DEM is clipped to smaller extent than orthomosaic
« Reply #2 on: November 17, 2016, 09:14:44 PM »
I am using Dense Cloud. I don't know how it would be cropped, isn't the extent set based on the bounding box? If it were cropped, how would I check that? Thank you for your help.

mguy

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Re: DEM is clipped to smaller extent than orthomosaic
« Reply #3 on: November 18, 2016, 05:17:14 AM »
I also wanted to add that when I turn on the mesh model and select "solid" or "wireframe" i get the result shown in the attached image. It looks like the area that is being used to generate the DEM corresponds to the same area in the shaded model. Perhaps this explains what is going on?

Dave Martin

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Re: DEM is clipped to smaller extent than orthomosaic
« Reply #4 on: November 18, 2016, 12:16:17 PM »
Guy - I've never experienced the problem you describe, but just looking at your last screenshot it occurred to me that, as the bounding box is 3-dimensional, are some of the missing areas 'above' or 'below' the bounding planes? - if you haven't already done so, it might be worth rotating that view to check that all the topography is within the bounding box.

Dave

mguy

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Re: DEM is clipped to smaller extent than orthomosaic
« Reply #5 on: November 18, 2016, 07:50:03 PM »
David - you are absolutely right! Thank you so much. I am confused how that happened but glad to have it fixed. Thank you again.

Dave Martin

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Re: DEM is clipped to smaller extent than orthomosaic
« Reply #6 on: November 18, 2016, 10:35:29 PM »
Thanks for the feedback  :)

Dave