This seems to be a bug somewhere, either in CesiumJS or in gltf-piepline (or… maybe in both…).
But could you provide more details about how you are applying the draco compression?
I tried it out with
gltf-pipeline -i Uncompresed.glb -o Compressed.glb -d
(using all the defaults for Draco, with the -d parameter), and this is the resulting GLB:
Compressed.glb (156.1 KB)
It does render in CesiumJS, but … not exactly right:
This seems to be caused by the materials of the resulting glTF containing semi-transparent colors. When manually changing the alpha mode of the output glTF from "BLEND" to "OPAQUE", then … this is the result:
Yeah… the geometry is there, but … it’s still not right. Why is everything red? I don’t know for sure, but the input glTF contains vertex colors, via the COLOR_0 attribute, so I assume that the fact that everything is rendered in red is what already has been described in Problem with Draco and unnormalized vertex colors · Issue #6561 · CesiumGS/cesium · GitHub