i dont konw why，i just rotate the camera，but different tansparency appeared，if i move quickly，the transparency is not smooth.By the way， the roof‘s transparency looks different from wall,is that normal?
https://www.babylonjs-playground.com/#MPIDNW#3
It’s an interaction with the ground created by createDefaultEnvironment.
As all elements are transparent, they are rendered in a depth sort order. Depending on your camera view, the ground is considered farther or nearer than some elements in the scene, so will be displayed before/after those elements, changing the apparence.
If you disable creating the ground, you will see there are no problems:
oh! It works.
Thank you! 