When I use a pack with models (or not), models show faces facing away from the player.
When this happens it creates a whole lot of texture fighting on planes such as vines and grass, and you can see the other side of glass
What's weird is it stopped this one time, but next time I logged in it did it again :/
Steps to Reproduce:
1. Make a new empty custom flat world
2. Copy a schematic from an older version into the world
3. And possibly this?: http://www.planetminecraft.com/texture_pack/conquest-3d-model-pack-addon/
Turns out when I deleted all my files the problem was fixed :/