It's hard to explain, but in the screenshots in the attachments, the shading turns black for certain sides of the model depending on the blocks next to it. So, if the block has another block on the right of it, all sides of the model facing right will be black. Along with the screenshots, I will also attach the resource pack so you can test it out yourself. Edit: I have smooth lighting off and graphics set to fast.
Is this still a concern in the current Snapshot 14w25b or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.
Note: 3d packs have to be reworked, since the model format has changed in 14w25, see MC-56987
Apparently this was fixed, likey around the time of cullface's addition (14w25a). All you need to do is set the cullface property to the side you want it to be lighted via (eg, if you have an inset face on the north side, set all parts of the inset face to cullface to the north)
It still doesn't work on smooth lightning, so I suggest changing the issue to state only on smooth lighting
It has been fixed on 1.8.x (don't know about earlier versions). 3D models worked with smooth lighting, all you had to do was set proper face culling. Now the problem with smooth lighting and 3d textures is back.
It hasas been fixed on 1.8, but it's back with the change to models (or it's something else that caused it) in snapshot 15w31c.
It's just a simple model to show the issue, sent in 2 resourcepack because in snapshot 15w31c and above "cullface" has been slightly changed and they aren't compatible.
Yes this problem only occurs with smooth lighting on (the bug is "Custom 3d Model Lighting Bug on smooth lighting" for some reason). Minecraft thinks that every face that is facing for example "up" should have smooth lighting like the face that is on the very top of the block (the one touching other block). But I just noticed that it may have never been fixed in 1.8.x. In 1.8 the smooth lighting doesn't seem to work on custom models with cullfaces. That made it work like with "smooth lighting off" and kind of fixed the issue.
The incompatible thing is probably caused by "pack.mcmeta" because I used the same as in 1.8.
Confirmed. Added another screenshot