Define a tileset with implicit_tiling that matches the geodetic tiling

[pjanetzek]

Hello I'm trying the implicit_tiling and wonder what is the best way to define a tileset that matches the geodetic tiling with two root nodes. Was this considered or do you have any recommendation how to achieve this with the current spec?

Thanks!

[lilleyse]

@pjanetzek it would look something like this - two root tiles, each with implicit tiling.

{
  "asset": {
    "version": "1.1"
  },
  "geometricError": 631380.3810809468,
  "root": {
    "boundingVolume": {
      "region": [
        -3.141592653589793,
        -1.5707963267948966,
        3.141592653589793,
        1.5707963267948966,
        -113.30585479736328,
        306.65130615234375
      ]
    },
    "children": [
      {
        "boundingVolume": {
          "region": [
            -3.141592653589793,
            -1.5707963267948966,
            0,
            1.5707963267948966,
            -91.98120880126953,
            306.65130615234375
          ]
        },
        "content": {
          "uri": "0/{level}/{x}/{y}.glb"
        },
        "geometricError": 157845.0952702367,
        "implicitTiling": {
          "availableLevels": 16,
          "subdivisionScheme": "QUADTREE",
          "subtreeLevels": 7,
          "subtrees": {
            "uri": "0/{level}/{x}/{y}.subtree"
          }
        }
      },
      {
        "boundingVolume": {
          "region": [
            0,
            -1.5707963267948966,
            3.141592653589793,
            1.5707963267948966,
            -113.30585479736328,
            84.61588287353516
          ]
        },
        "content": {
          "uri": "1/{level}/{x}/{y}.glb"
        },
        "geometricError": 157845.0952702367,
        "implicitTiling": {
          "availableLevels": 5,
          "subdivisionScheme": "QUADTREE",
          "subtreeLevels": 7,
          "subtrees": {
            "uri": "1/{level}/{x}/{y}.subtree"
          }
        }
      }
    ],
    "geometricError": 315690.1905404734,
    "refine": "REPLACE"
  }
}

[pjanetzek]

Thanks a lot! This works indeed :)

[lilleyse]

Great!

[pjanetzek]

Thinking about this more I think it would be very handy to support the TMS tiling with two roots directly so that one could use existing tile servers without having to translate the URL somewhere.
E.g. one use case would be to use available quantized-mesh terrain data with an own cesium GltfConverter.

[lilleyse]

Yes, I could see there being higher level tiling schemes like TMS global-geodetic that implicitly translate to the example above.