QuantizedMeshPlugin stops requesting tiles above level 10 when metadataAvailability is set

[code-soldier]

Question

I believe there is an issue in QuantizedMeshPlugin related to how metadataAvailability is handled.
Tiles above level 10 are never requested, even though the terrain supports higher LODs.
I tracked the problem down to the following logic in the source code:

// src\three\plugins\QuantizedMeshPlugin.js

// Calculates whether the given tile should have metadata availability
function getTileHasMetadata( tile, layer ) {

  const level = tile[ TILE_LEVEL ];
  const metadataAvailability = getMetadataAvailability( layer );
  const maxLevel = getMaxLevel( layer );

  return level < maxLevel &&
         metadataAvailability !== -1 &&
         ( level % metadataAvailability ) === 0;
}

In my case, layer.json looks like this:

{
  "maxzoom": 19,
  "metadataAvailability": 10
}

Because metadataAvailability is 10, tiles at level 10 are treated as having metadata.
As a result, tile[TILE_AVAILABLE] is not set for level 10 tiles, and no child tiles are created, so subdivision stops at level 10.

However, the same terrain tiles render correctly up to level 19 in Cesium

Supplemental Data

Library Version

0.4.19

Three.js Version

r180

[gkjohnson]

Please provide a repro case. The "quantMeshOverlays" demo works when relying just on availability metadata and loads down to children at depth 19.

[code-soldier]

Please provide a repro case. The "quantMeshOverlays" demo works when relying just on availability metadata and loads down to children at depth 19.

https://github.com/code-soldier/temp.git
I guess the way I create the terrain might be incorrect.

[gkjohnson]

In my case, layer.json looks like this:
"metadataAvailability": 10

Your layer.json specifices that every 10th layer contains availability data but the assets do not. Your layer.json also specifies a full set of availability ranges for a full 20 layers, which isn't necessary when specifying "metadataAvailability". Cesium may check both fields but the QuantizedMeshPlugin in this project only checks metadata if "metadataAvailability" is specified.