How to export Unity's environment reflection texture(Cubemap with custom mipmaps) to Babylon?

[Intelligence]

Unity’s environment reflection texture is .exr file with custom mipmaps. Does Babylon’s CubeTexture support custom mipmaps? Using custom mipmaps here, I mean I don’t want the mipmap to be automatically generated, I want to provide custom mipmaps.

[Evgeni_Popov]

Welcome aboard!

Duplicate of Does Babylon's CubeTexture support custom mipmaps?, let’s continue in this other thread.