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A comment on Using Lidar to map tree shadows. Parent comment

Re:Using Lidar to map tree shadows by tppiotrowski on Sunday July 09, 2023 @10:14PM (#36661242)
Great points. Thank you for the links. The one trade off here is that uncompressed blobs will require longer downloads than PNG and I think usually the network transfer is slower than PNG decoding.

But maybe the sample gist takes a Tiff blob and encodes it to a PNG on the client and then maplibre decodes the PNG to canvas. That would be quite inefficient if that's what it's doing.

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Re:Using Lidar to map tree shadows by blacha on Sunday July 09, 2023 @11:04PM (#36661567)
Those comments were more at pastmaps.

For elevation data, we store our DEM/DSM in S3 as LERC [1] COGS, LERC has a WASM bundle which I think can be used in the browser. We found LERC COGs to be one of the most space efficient ways of storing highresolution DEM/DSM data [2], If you wanted to you could fetch LERC tiles directly out of a remote COG and use that directly for the terrain heights.

I am more focused on storage/archiving/publishing of our LiDAR capture program [3] than web based visualizations of it though, so I am unsure if a LERC COG would even be better for you than a PNG TerrainRGB.

[1] https://www.npmjs.com/package/lerc

[2] https://github.com/linz/elevation/tree/master/docs/tiff-comp...

[3] https://linz.maps.arcgis.com/apps/MapSeries/index.html?appid...

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Re:Using Lidar to map tree shadows by Pabloski80 on Sunday July 09, 2023 @11:23PM (#36661682)
WASM surely could be an improvement over js, especially for kind of BigData-ish/repetitive jobs, and where load on clients might become the next wall after we optimized the cloud/server part, or when we try to use js on cloud leafnodes.
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