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Working with Lidar data in WW

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  • jimmiller
    started a topic Working with Lidar data in WW

    Working with Lidar data in WW

    This topic is devoted to all things related to Lidar data visualization, analysis, and editing. I have been developing a tool for the past couple of years. It is documented and can be run from: http://people.eecs.ku.edu/~miller/Wo...dar/index.html. In addition to basic visualization, interactive capabilities include rendering based on (nearly) any per-point attribute in the file, filtering based on the same, spatial filtering based on airspaces and/or (some types of) shapes in an ESRI shape file. Subsets of a lidar file can be saved. Various editing capabilities exist including adding imagery to the points (stored as per-point RGB) and adding LAS codes to the points based on image files or shape files. The documentation at the web site listed above describes these and other capabilities.

    There are two programs documented on the site that can be run: one is a World Wind application that displays the point cloud georeferenced on the globe; the other is a standalone application that offers many of the same interactive capabilities. This non-world wind application is useful for at least two reasons: (i) much larger lidar files (and/or much larger subsets of given files) can be displayed, and (ii) many lidar files do not contain information describing their coordinate projections and hence cannot be reliably placed on the globe.

    I welcome any and all to try out the applications, share your experiences, and generally participate in a discussion of all things lidar!

  • milamolsen
    replied
    well,the thing is,With a quad core,yes with quad core and fiber optic 200MB downloaded the main default file and took just 20 minute break,just 20 minutes. Omegle Nothing on the first app.The WW app loaded fast but no lidar data. https://omegle.site/

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  • kiliyatsia
    replied
    Originally posted by j0landre View Post
    We have seen your work for some time. Congratulations for this great job. It has allowed us to test the Sprinfield data lying on the display that you have made on your site.
    Finally, we have developed our own solution to display a point cloud.
    For the moment, we are able to color points by intensity, filezilla uc browser rufus classification and elevation.
    In input, we are opening two kind of file :
    - A las file associated to a proj4 file (for the projection),
    - A txt file which contains xyzRGB points.

    You can see what we are displaying in the screenshots below.

    We also would like to know the maximum file size you are able to open / display in your WWJ app.

    Thank you Mr Miller.
    There are two programs documented on the site that can be run: one is a World Wind application that displays the point cloud georeferenced on the globe; the other is a standalone application that offers many of the same interactive capabilities. This non-world wind application is useful for at least two reasons: (i) much larger lidar files (and/or much larger subsets of given files) can be displayed, and (ii) many lidar files do not contain information describing their coordinate projections and hence cannot be reliably placed on the globe.
    Last edited by kiliyatsia; 07-28-2019, 09:48 PM.

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  • Mthawani
    replied
    Hello,

    I work for the dod and have the same needs to work with Lidar within my ww application. Can you please provide a link to the respository location where the source code for ingesting Lidar data is stored. (Myspringfield)

    Thanks
    Manu

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  • jimmiller
    replied
    Here are some recent updates and current directions. We have been working on segmentation of the unorganized point cloud data in an attempt to isolate structures like buildings from the lidar data and generate explicit boundary representations for them. This effort begins by defining filters that utilize the various per-point attributes in an attempt to extract just those points that are likely to be buildings. Our friends from the City of Springfield, Oregon have been developing some very nice filters for that part of the process. Given the (still spatially unorganized) points that pass through those filters, I send them through an implementation of the DBSCAN algorithm to collect individual objects together into so-called "clusters". Each cluster then corresponds to a building. The points in the building cluster are still spatially unorganized, so I create "Partitioned Neighborhoods" (PNs) for each point in a cluster. These PNs allow me to determine first what the boundary points of the cluster are, then I can also use the PNs to initiate a spatial ordering of the identified boundary points into a set of edges that completely bound the cluster/building. The boundaries tend to be a bit noisy and have excessive numbers of points, so I am currently experimenting with a set of postprocessing filters that use various strategies to thin out vertices, refine edge geometry, and sharpen corners. This work is ongoing, as I am still exploring how best to tune these individual postprocessing filters as well as determine the best way they can operate - in unison, one after the other, etc.

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  • jimmiller
    replied
    Yes, the app is contained in the branch.

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  • softwaremike
    replied
    We have an app in which WorldWind is embedded. Our users would like to be able to plot LIDAR data. I think, from an end-user LIDAR perspective, your app already provides everything our users would need; however, we'd need it in our app, not as a separate app.

    Is the LIDAR branch of code the same as your app?

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  • jimmiller
    replied
    I will have to check on their schedule. I assume you are able to run the app as posted. What facilities do you need that are not there?

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  • softwaremike
    replied
    Any chance that branch can be "opened" to the general public? My team might be willing to do some work on the LIDAR capability to "finish" it (depending on what's left for it to be completed?)

    Thanks in advance,
    Mike Johnson

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  • jimmiller
    replied
    The code is stored in a branch of the WW repository. I don't know the current status of or plans for how this branch is to be made available. But I believe the plan is to make that happen at some point.

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  • softwaremike
    replied
    Is this work related to issue WWJ-304 (http://issues.worldwind.arc.nasa.gov...s:all-tabpanel)?

    Is the code for the LIDAR import/render available?

    Thanks in advance,
    Mike Johnson

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  • nlneilson
    replied
    Thanks for clarifying what the app/s do.

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  • jimmiller
    replied
    Neither app (LASVisEdit on the left nor LASVisEditWW on the right) are designed to automatically load a lidar file. Both present the "Lidar Controls" window with its invitation to load one of the standard demo files, but both apps were designed for use by people that have their own files to view, hence automatically pre-loading files is an unwanted initial step for them since they would have to wait for the load, then undo it by deleting the file before they could actually start doing their work.

    LASVisEditWW (app on the right) will automatically travel to the correct location on the globe once it reads a file and determines where it is to be placed.

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  • nlneilson
    replied
    jimmiller
    The example on the left may have required me to select a file as I just clicked the default.

    The example on the right loaded OK but did not know what was to be shown.
    Is the Lidar data just for a specific area?

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  • jimmiller
    replied
    Originally posted by Brandt View Post
    Nice Work Jim, Iíll be posting links on the Oregon Elevation Framework Implementation Team (DAS-Geo) site soon.
    Great. I look forward to their comments. Thanks, Brandt.

    Leave a comment:

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