Some glTF files are displayed in white

[cx20]

I tried to display the glTF sample below with ClayGL. https://ft-lab.github.io/gltf.html

However, some glTF seems to be displayed in white. (For example, apple.glb, grass.glb, rocks_trees_ao.glb)

ClayGL + rocks_trees_ao.glb result:

Three.js + rocks_trees_ao.glb result:

Because it displays correctly in other libraries, I think that it is a problem of ClayGL.