Global Mapper Pro

Problem When Cropping Contours to Selected Area

Eagle2
Eagle2 Global Mapper UserTrusted User
edited September 2011 in Vector Data
Hello all,

I'm not sure if there is a feature in Global Mapper that can help me, but I'll ask anyways. I'm working on a large LiDAR job, with contours as one of the final products. I've generated contours in DGN format using our LiDAR software. These contours are split into 1km x 1km tiles, and extend outside the final boundary. I need to both convert to DWG format, and clip to the final boundary. I've been using the batch convert method, and selecting the boundary as an area object to clip all exported files to. This works perfectly except for closed contours. It seems Global Mapper is interpreting these as closed areas, and when clipped, these contours are closed along the boundary. I've attached before and after photos for clarification. Any suggestions for how to eliminate this? Unfortunately for this dataset I'm required to use the contours I have, so generating new contours in GM isn't an option.

Thanks in advance,

Bryan

Before Clip.JPG
Before the contours are clipped.

After Clip.JPG
After clipping.

Comments

  • global_mapper
    global_mapper Administrator
    edited September 2011
    It looks like your Lidar software generated closed contour areas rather than just lines, so when those areas are cropped using Global Mapper they of course stay areas and close along the crop border. To fix this, select all of the features with the Digitizer Tool, then right-click and select the toolbar option to create lines from the selected areas. Then, go to the Vector Display tab of the Configuration dialog and turn off area display, then do the clip. You should only have lines left.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Eagle2
    Eagle2 Global Mapper User Trusted User
    edited September 2011
    Hi Mike

    As always, thanks for the speedy reply. I've had a look at the contour generation routine in our LiDAR software and found an option to disable complex chains, which seems to have solved the problem. Now I can batch convert and clip without any problems.

    Thanks again,

    Bryan
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