Hi !
This PG achieve that how to create reflectionTexture with SkyMaterial(Babylon.js Playground), how can I create environmentTexture with SkyMaterila?
I try to set probe.cubeTexture to scene.environmentTexture, it seems that didn’t work
https://playground.babylonjs.com/#4R1H1U#30
You are simply missing to put the probe texture in the scene custom RTT https://playground.babylonjs.com/#4R1H1U#31
If I use a RT in a scene, should I must push it into scene.CustomRT?
It depends unfortunately 
If you want to render it every frame and it is not used as a reflectionTexture or a refractionTexture explicitely in Standard or PBR material yes, this is the simplest way to achieve it.
I guess environment texture should be accounted for as well in our setup, this would make sense in the probe case.
This will be in the next nightly
Oh, thank you for you help! I think I understand this point 