potree

[radoslavirha]

Hello is it possible to visualise potree point clouds? Thanks

[kylebarron]

I think there's been discussion about loading potree data in loaders.gl visgl/loaders.gl#257 and visgl/loaders.gl#212

[ibgreen]

We do have an experimental @loaders.gl/potree module that is intended to load and "normalize" potree data so that it can work with the deck.gl Tile3DLayer.

I seem to recall that there was a problem in the past that potree data did not contain geospatial reference point but this may have been addressed in latest version of potree. Alternatively it could be supplied as a parameter by the application.

It would likely not be hard to get everything working, just a matter of finding some interested contributor to help complete the effort.

[radoslavirha]

It does not work now, it's missing refine (refine is in Cesium 3d tiles I think). Potree data is .las converted by Current potreeConverter

const potree = await load(`${this.$configuration.api}${layer.path[0]}/metadata.json`);
const tileset = new Tileset3D(potree);

I also tried some urls from Potree examples (v1.7), but without success.

[ibgreen]

Understood. You could just do a one line change / PR and update the Tileset3D code to apply a default refinement (or set the field in the potree loader). Of course, there is no guarantee we don't hit additional issues. Would be happy to help you work through the issues as they come up. Depends on your appetite for getting your hands dirty...

[radoslavirha]

Hello,

I've tried to add refinement, but it won't be enough I think. My colleague sent me potree 2 format and it's different from older format. The major difference is in the file structure. Potree 2 is one huge .bin file loaded in chunks (inspected in potree viewer with potree 2 data), potree 1.7 is much more similar to cesium 3d tiles with bunch of smaller .bin files. So before we can help you, we need to decide which format is best for point clouds. What is your preference?

format	pros	cons
cesium 3d point clouds	deck.gl support	conversion from .las/.laz
		FME converter is not good enough - poor LOD
		ION converter is good, but supports only few input formats
		cesium 3d point clouds from ENTWINE converter seems to be less performant (tested on colored point clouds) ... maybe deck.gl issue ... will test it more
potree	easy conversion	not supported in deck.gl
.las/.laz	no conversion	max 100mb file

We have huge georeferenced point clouds in .las/.laz format. Maybe we can convert it to .ply too and test it https://loaders.gl/examples/pointcloud? Can you please advise us what will be the best choice to visualise huge point clouds?

Thanks :)

[ibgreen]

Thanks for the update on potree 2 format. Yes it does indeed look like potree 2 requires supporting HTTP range requests to load out the data for each tile from a single resource (the data is still tiled, just needs to be loaded from ranges in a big file, rather than from individual files). Range request loading is not supported by the related loaders.gl code at this stage, though likely not too hard to add for someone making PRs.

I am not sure PLY is smaller than LAZ as LAZ is a compressed binary format (where as LAS is uncompressed per my understanding), and PLY is uncompressed. It depends to a certain extent on precision of positions (I think LAS supports 64 bits which if used obviously takes more space) and how many additional data columns you have per point "row".

Another compressed point cloud format is Draco3D which is well supported by deck.gl and loaders.gl.

The main development focus for tiled 3d data in loaders.gl right now is I3S but unfortunately we have not yet implemented support for I3S point clouds, and I am not sure there are point cloud tiling tools that would help you.

It is unfortunate that your input files are not supported by ION. Another approach could be to add Writers for point cloud formats in loaders.gl so that you could use loaders.gl to convert to a format supported by Cesium ION.

There should be an experimental C++ point cloud tiler (generating 3D tiles) in loaders.gl cpp folder but it has not been maintained not sure if it is worth looking at right now.