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We have been continuing to make improvements to the LiDAR module automatic classification tools that improve how they handle UAV collected LiDAR or photogrammetric point clouds. The most recent improvements have not been through the full QA process yet, but are available in the daily build of the application: http://data.bluemarblegeo.com/downloads/global-mapper/dailybuilds/
We have many users successfully working with UAV collected lidar data or photo-derived point clouds. Here is one case study: http://www.bluemarblegeo.com/docs/case-studies/dronemapper-case-study.pdf
Here is the help file information about the tools: http://www.bluemarblegeo.com/knowledgebase/global-mapper-18-2/#Lidar_Module/Automated_Lidar_Analysis_Tools.htm
We also just completed a Lidar Webinar series that talks more about these settings:
Upon request to email@example.com we can also provide additional information about the classification algorithms used, or suggest settings to refine the automatic classification given a data sample.
The recommended workflow for a completely unclassified point cloud would be to first perform noise detection using the standard deviation setting. Then perform the ground classification. The settings in the 'removal of likely non-ground' section are a pre-filter, that will remove points from consideration based on changes in height. The latest changes also include a setting here for the 'Maximum Building Width', which was a change made to help with cases like large commercial buildings, where part of the flat roof may become classified as ground.
If you are having trouble with the values, we would recommend running the algorithm on a small section of the data using the Specify Bounds option. Tweak the setting on that sample area to get a good classification result, and then apply the same values to the whole point cloud.
Hello,joebocop said:I have imported a SHP file of polygon features. Each polygon has an R, G and B value, representing the colour that should be used to style the area background.
How can I use these values to tell GlobalMapper 18.1 (b022117) which colour to use as a background style for each feature?
You can combine your R, G, and B attributes into a single attribute called FILL_COLOR, then save your data as a shapefile and reload it into Global Mapper. When the data is imported, Global Mapper will use the FILL_COLOR attribute to style the areas.
To combine the attributes, you can use Layer | Calculate/Copy Attribute Values. On the Attribute Calculation Setup screen, after you type the attribute name (FILL_COLOR), choose the option to Use Formula Calculation, choose String for the Calculation Mode, and type the following information in the Enter Formula field:
"RGB(" + R + "," + G + "," + B + ")"This assumes that your color attributes are called R, G, and B. If they have different names, use those instead.
After you modify the data, you will need to export the file, then import it again, because Global Mapper applies the style from attribute values when it imports the data.
One thing to be careful of when you're working in the Search Vector Data dialog: values that appear to be numeric may be sorted as text, such that , say, a value of "2.03e2" is sorted as being less than a value of "200", when 203 is clearly greater than 200. The interpretation of attribute values when sorting in the attribute table is governed -- somewhat confusingly -- by a dropdown a few rows above the table headers in the "Search Criteria" group. To the right side, there's a dropdown labeled "as" with the choices "Text" and "Number". If you select "Number", then click on the attribute column header, you should find that the column sorts the values will sort correctly.