Support PotreeConverter 2.0 format

[lc-guy]

Context

For about 6 months now (since the release of PotreeConverter 2.0), the output format for the generated octree has changed: instead of having one file for each node, there's 3 files in total, with 2 of them being binary files holding the actual data while the last is a JSON metadata object. iTowns currently only supports the old format. I wanted to know if it would be possible to implement the new format, or to at least have some pointers as to which parts of the iTowns codebase I need to change in order to implement support for this new format.

Possible Cause/Fix/Solution

The 2.0 loader code for Potree. Code creating the metadata file. Additional details in a related repo: https://github.com/pnext/three-loader/issues/79#issuecomment-708309637

[zarov]

Do you have a sample converted to Potree 2.0 to work with? If so I can give you hints on what part of iTowns to change.

From what I understand so far, this part needs to be added to the fetch request in iTowns. For that you'll need to overload PointCloudNode#load to have the Range part added to the networkOptions object. I think most of the current process for managing point clouds should work out of the box, but I may be wrong. You also need to modify PotreeBinParser to support partial reading of a file.

[gchoqueux]

There is a another way to load Potree 2.0 in iTowns, it's use directly Potree. see this example

[PerspectivesLab]

is there any news of native support of potree 2.0 in itowns ? is it in the roadmap ? thx

[jailln]

@LoicUTC and @PhilippeMarc-IGN roadmap question to adress :)