Clarify hidden / missing faces management

[segmentationfault777]

Hi! Could you confirm my understanding :

• if some faces are missing in the source ply file, mvs won't try to "re-mesh" them. those missing faces will still be missing in the final obj and appear as "holes"
• MAX_HOLE_NUM_FACES and MAX_HOLE_PATCH_SIZE : a hole is a set of faces without texture because no image in the scene could be applied to them. if a hole meets the conditions of those parameters, mvs creates a texture patch for its faces
• keep_unseen_faces = true : in the final obj, some faces may have no texture, for example when no patch could be applied to them. this parameter will make mvs keep those faces and apply a kind of "random" color to them. if set to false, mvs will remove the faces from the final obj

thanks!