So I\'m using a custom model made in blender for ThreeJS. I exported it to a .obj file and used the Three-js conversion utility to make a json file. I have it set to ro
three.js assumes that front-faces have counter-clockwise winding order. Stated another way, the front-face in three.js is determined by the winding order of the face -- not the face normal.
It is likely that front-faces in your model have clockwise winding order.
A work-around that does not require you to change your model is to set:
mesh.material.side = THREE.DoubleSide;
three.js r.85