Snapping to Lines

jmpreiksjmpreiks Global Mapper UserPosts: 41
edited June 2010 in Vector Data
Hi,
Is there is any way to make the digitizer snap to existing lines? It snaps to the vertices of these lines, but not the "edge" of the line.

Thanks,
Justin

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2008
    Justin,

    The digitizer should already snap both along lines and at line vertices when drawing new line and area features. Is this not what you are seeing?

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • jmpreiksjmpreiks Global Mapper User Posts: 41
    edited March 2008
    I am drawing a new line feature, and it does not snap along a line, only the vertices. I am using 9.02, build date: March 13

    Justin
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2008
    Justin,

    Are you holding down the 'V' key when drawing the line? This would cause the snapping to only be done to vertices.

    Also keep in mind that if the cursor is pretty close to a vertex (within 6 pixels) it will snap to the vertex rather than the nearest point along the line. This could come into play if your line has a lot of vertices where you are clicking.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • jmpreiksjmpreiks Global Mapper User Posts: 41
    edited March 2008
    It seems to work for some lines and not others. The lines that I am trying to snap to are in a GM package file if that makes a difference.

    I just tried it again, and it would snap to one line and not another. The features are contained in two separate package files. The vertices are far apart on both.

    Justin
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2008
    Justin,

    That is strange. If you can provide me with a package file that isn't being snapped to I can take a look. You can post it here or email it to support@globalmapper.com.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • jmpreiksjmpreiks Global Mapper User Posts: 41
    edited March 2008
    Unfortunately I cannot send you the package, but I figured out what determines what is snapped to and what isn't. It seems to only snap to features that are in the same projection as GM is currently operating in. I have several packages and catalogs that are in multiple different projections; I couldn't figure out why the features that I couldn't snap to kept on changing, until I noticed it happened when I was changing projections.

    Let me know if there is something that can be done about this. It would be an extremely useful tool for me.

    Thanks,
    Justin
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited March 2008
    Justin,

    Aha, that was it. The snapping was not working if the projection of the line did not match the view projection. I have placed a new build at http://www.globalmapper.com/global_mapper9.zip with this fixed for you to try. Simply download that file and extract the contents into your existing v9.xx installation folder to give it a try.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • jmpreiksjmpreiks Global Mapper User Posts: 41
    edited March 2008
    Thanks Mike!

    It seems to work perfectly now.

    Justin
  • iaoranaiaorana Global Mapper User Posts: 133Trusted User
    edited June 2010
    Hi Mike,
    I encounter problem with snapping.
    When I want to snap to an intersection of lines that has no vertex, It snap only on one line.
    The other problem is one I select with the digitizer areas that are overlaid in the same layer.
    How can I toggle to select the area that are undrneath the selected one.

    Thanks
    Iaorana
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2010
    Iaorana,

    There isn't any way to snap to an intersection if there aren't any vertices there, other than just clicking very near the intersection and hoping to get close. You can have vertices inserted at the intersections by selecting the lines with the Digitizer Tool, then selecting the option to insert vertices at the intersections, then you can snap as you want.

    If you have multiple overlapping areas within the same layer, your best bet for selecting an underlying area is to drag a box through an edge of the area that you want to select.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
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