More Control Over Contour Map Export

There’s no settings regarding how contours are generated. Please add more control similar to what Pix4D or Metashape allows which enables to produce smoother contour lines more typical of what you see in Survey documents.

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You are wanting smooth contour lines for visual aesthetics correct? Obviously the more you decimate the contours the less that can be done with them on the backend and the less accurate they are. I agree that it would be nice to showing a nice flowing contour map. Have you tried 2ft contours?

Consultant, why would you want to dull down the data. Accuracy with drones is far better than a typical survey. People pay more for ugly contours because the smooth contours you are referring to were more than likely done with a traditional survey with 1/1000000 the amount of points.

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There is an advantage to smooth contours, but technically for a useless cause. Non-technical people like to see contours to get an immediate visual on highs/lows, water flow and etc., but the color elevation map do that just as well and when used with transparency is much more effective with the ortho behind it. Contours clutter. If the client absolutely wants “pretty” contours I download the 2ft and recreate smoothed 1ft with CAD.

In the real world, in most cases a site isn’t going to be 100% bare ground. In addition, none of the photogrammetry software I’ve used has a perfect AI algorithm that will completely remove shrubs and trees. In many cases there’s a small ‘hump’ where the software attempted to remove the vegetation. Much better than the surface model with no filtering, but still, not good enough sometimes for the Land Surveying companies I work with. So while theoretically the DTM is higher resolution and thereby “messy” looking and not smooth like a traditional topo, much of the small, short changes in the contour lines are caused by vegetation.

The additional settings that are available in Pix4D and to a greater extent in Metashape allow adjusting the DTM filtering to filter better resulting in a DTM that is more accurate without having to spend hours to manually edit the dense point cloud. This includes being able to filter the point cloud by color which DD doesn’t do, it’s only by angle of adjacent points. I determined all of this by doing over 100 maps with all three software packages and working with Land Surveyors on a variety of different types of terrain makeups.

This isn’t just about aesthetics.

You and your Surveyors should look into Carlson Precision 3D Topo. NOTHING is perfect, but we get +/- 2in stakeout on our DTM’s. People, cars, trees and equipment are very easy to remove. The DTM fixes allot of the contour noise and you can define a tolerance for a minimum contour length so little hump don’t get drawn. All under the theory that a contour map is useless to Surveyors. I’ve been doing this for 20+ years and to me they don’t little more than clutter a drawing.

For DTM’s Carlson P3D Topo > Metashape > Pix4D.

Aesthetics should not be a part of Surveying. People also need to realize that drone mapping is a survey tool and should follow the same guidelines and regulations.

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