How to create Cross Sections (3D-lines) with lidar data?

scrscr Global Mapper UserPosts: 42Trusted User
Hi, I can't figure out how I get Cross Sections (3D-lines) out ouf a point cloud.
I can use the path-profile tool and can export the points of one profile, but I don't get a 3D-line.

Is there an other tool or function that I don't see?

Any ideas?

(I would not like to transform the pointcloud to an elevation model first)

Thank you.

Rainer
DerrickW

Answers

  • DerrickWDerrickW Posts: 26
    I can't think of a way of doing this without creating an elevation model first, SCR.  Not without a lot of manual work, at least.  

    How I do it: 
    Import your centerline
    Generate perpendicular lines along centerline
    Resample/add vertices to the perpendicular lines to a suitable spacing for your site
    Generate elevation grid from point cloud (Thin it if needed) 
    Apply elevations to perpendicular lines. 


    If you have very specific locations or station numbers that the lines need to follow (including the vertices), I normally do all of that in CAD and export the locations out as points, then apply elevations in GM, and pull them back in to CAD.  

    I'm assuming you don't want to create an elevation grid because it murders your computer when doing that on large point clouds?  If you're using a LiDAR-derived point cloud, you should be able to filter it by return type/classification and then use the point cloud thinning tool to make this more manageable.  You could also buffer your cross sections and only generate a grid within those buffers, if needed.    

    If you're using a photogrammetry-derived point cloud....It's going to take some manual work one way or another. 
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