I noticed that when I displayed [Avocado.gltf](https://github.com/KhronosGroup/glTF-Sample-Models/tree/master/2.0/Avocado) in Ashes, it was glossy. I don't think the display result of PBR material is correct. [Ashes v0.2.6 + Avocado.gltf result:](https://cx20.github.io/gltf-test/examples/ashes3d/index.html?model=Avocado&scale=30.0)  [Three.js r112 + Avocado.gltf result:](https://cx20.github.io/gltf-test/examples/threejs/index.html?model=Avocado&scale=30.0) 