I have been searching around and haven\'t found any really good answer to my question yet..
The thing is that I have this sphere.. just a basic sphere, and I want to flip th
The flip of an object with a negative scale object.scale.x = -1 also reverse the normals since three.js r89 (see: Support reflection matrices. #12787).
(But I have to upgrade to r91 to solve my normal issue.)