Add route to load full mesh stl of a segment/agglomerate

[fm3]

• Adds possibility to download meshes as STL (both for meshfile, ad-hoc, both for annotations and view modes, both for mappings and oversegmentations): POST <datastore_uri>/data/datasets/:organizationName/:datasetName/layers/:dataLayerName/meshes/fullMesh.stl and POST <tracingstore_uri>/tracings/volume/:tracingId/fullMesh.stl with json body:

     meshFileName: Option[String], // None means ad-hoc meshing
    lod: Option[Int],
    segmentId: Long, // if mappingName is set, this is an agglomerate id
    mappingName: Option[String],
    mappingType: Option[String], // json, agglomerate, editableMapping
    editableMappingTracingId: Option[String],
    mag: Option[Vec3Int], // required for ad-hoc meshing
    seedPosition: Option[Vec3Int], // required for ad-hoc meshing
    additionalCoordinates: Option[Seq[AdditionalCoordinate]]

• Introduces subproject webknossosNative which makes use of JNI to provide native functions (currently only one: a dracoToStlConverter)
• Some renamings to unify things: webKnossos → webknossos in some more places in the backend code and adHocMeshing → adHocMesh
• new dependency draco
• removes the subsamplingStrides feature for ad-hoc meshes. This was already unused. Compare internal discussion.

URL of deployed dev instance (used for testing):

• https://loadfullmesh.webknossos.xyz

Steps to test:

• Create volume annotation, brush some, test via curl 'http://localhost:9000/tracings/volume/71a2eaeb-3413-4c88-a99c-45547e6d9de5/fullMesh.stl?token=secretSampleUserToken' -X POST -H 'Accept-Encoding: gzip, deflate, br' -H 'content-type: application/json' --data-raw '{"mag": [1,1,1], "seedPosition": [99, 102, 81], "segmentId": 1}' > out.stl (insert your tracing id, seed position)
• Test the datastore route as well
• Test other combinations (static mappings, editable mappings, brushed on mapping, meshfile is for oversegmentation, meshfile is for target mapping, other mags, other segment ids)
• Inspect downloaded stl files for example with meshlab on ubuntu

TODOs:

• Implementation for Meshfile
  • read mesh chunk infos
  • decode draco
  • serialize as headless stl
  • add single stl header
  • c++ error handling with try/catch, create java exception?
  • get a review by someone who is more familiar with c++
  • transform geometry with position
    • (+matrix?)
  • mapping support (also editable)
    • do not map ids if meshfile is already computed for this mapping
• Implementation for ad-hoc meshes
  • Encode ad-hoc mesh float buffer as stl
  • continue with neighbors
  • glue together the chunks better (overlap/merge vertices?)
  • mapping support (not editable, that goes to the tracingstore)
• Should also be available in tracingstore
  • Ad-Hoc
    • Should use segment index for meshing if available
    • how to get dataset voxel size?
      • Cache timeout?
    • Mapping support
      • Test after changing an existing mapped segment by brushing
      • Editable Mappings
  • With File: forward to datastore
    • with mapping support
    • Editable Mappings
• Measure perf
• test JNI stuff on mac
• Cleanup
• document JNI development process

Follow-up

• Parameter range listing route
• Python client
• Pass all infos to Render Animation Job

Issues:

• fixes Unified Mesh Loading API #7529

---

• Updated changelog
• Updated migration guide if applicable
• Updated documentation if applicable
• Removed dev-only changes like prints and application.conf edits
• Considered common edge cases
• Needs datastore update after deployment

[normanrz]

Code looks great! I'll do some testing next.

[normanrz]

Not sure if it is just the rendering in my Mac or if the normals in the STL are wrong