Global Mapper Pro

point label bug with output to mptiles

wmiswm
wmiswm Global Mapper UserTrusted User
using the latest build as of July 23, win8.1 with latest windows updates.

On screen, everything is correctly displayed, but when output to mptiles,
1. if point label position set to "automatic", some points will NOT have label appeared, some points will have one label at random position as expected, and some points will have two labels appeared (at two positions of course).
2. if point label position set to fix position, say "top right", some points will have one label at the correct position as expected (top right in this case), but A LOT OF points will not have label appeared.

Is there anybody encountering a similar situation?

Answers

  • Mykle
    Mykle Global Mapper User Trusted User
    On the dialog where you select the position, there is an option to "Always Display Labels" or similar wording. That is the primary one that is used. Exported files usually have text size appearing to be much smaller than on screen, and it may be the on-screen size that determines which labels overlap and won't be shown unless the Always Display option is used. There are a couple of options elsewhere that can affect labels, but I don't have GM on this computer to be of more help.

    Two labels sounds like duplicate points, or nearly overlapping points.
    You can investigate further by creating another layer, then moving a few points to that layer that are near another point. Hide the new layer and watch the behavior of the labels.

    Mykle
  • wmiswm
    wmiswm Global Mapper User Trusted User
    the bug is not related to overlapping or two points at very nearby locations. I have verified that the points in question are single points (having one single entry by searching all layers and all attributes, but displaying two labels), and they are very far apart from other points (say at hill tops etc, but having no label appearing).
  • wmiswm
    wmiswm Global Mapper User Trusted User
    and I have to repeat that the labels are perfectly normal on screen, only when output to mptiles, the bug appears.
  • bmg_bob
    bmg_bob Global Mapper Programmer
    edited August 2015
    This is a known issue in Global Mapper (bug number 15062). Labels that cross tile boundaries do not get exported.

    Currently the recommended workaround is to first export the vector layer with the labels to a single large raster image, like a GeoTFF, that covers the entire export area and with a high enough resolution that the text looks nice. Make sure the GeoTIFF has transparency enabled. Then unload the text layer and load the GeoTIFF with the labels back in, then export to the tiled format.
  • wmiswm
    wmiswm Global Mapper User Trusted User
    but unfortunately I have 24 layers altogether. Producing one geotiff for one layer is almost impossible in my situation.
    1. according to the resolution I need, each layer will be several GB in size
    2. the compilation of all the 24 layers together will require extremely large amount of ram, much exceed the limit of 32GB for non-server computers
    3. GM is not optimized for multi-thread processing, and I cannot use the trick of parallel computation for producing one single geotiff. This means, even if I can solve the huge ram requirement issue, I will need years of non-stop compilation to finish the job (obviously impossible for windows os).
  • wmiswm
    wmiswm Global Mapper User Trusted User
    Anybody know whether this bug has been resolved in GM v17?
  • bmg_bob
    bmg_bob Global Mapper Programmer
    This problem was not resolved not Global Mapper 17.
  • wmiswm
    wmiswm Global Mapper User Trusted User
    Extremely disappointed.  I cannot see why this simple bug cannot be easily resolved. The obvious mindless solution is to use one thread to generate a 9 tiles tmp image, without writing the tmp image to disk, then hand it over to another thread to crop the central tile out of this big tile. Most of the label length will not be longer than two tiles, therefore this simple solution will immediately resolve most of the cases. Computer resources is not a concern. At the moment GM can only use ONE thread efficiently. Adding another thread into the picture will not cause any real demand to computation resources.
  • wmiswm
    wmiswm Global Mapper User Trusted User
    Has this bug been solved in v17.1 ?
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