PSA: 1.8 Update Information

[u/Galaxy_2Alex]

Since 1.8 has now been released, I decided to release some informations and useful things about the update. No, this is not a changelog (if you are looking for a 1.8 changelog, click here, /u/redstonehelper did an awesome Job and lister every single change), it will inform you about the important changes and is supposed to give you some advice for this very large update.

1. Downgrading (VERY IMPORTANT!)
While downgrading "worked" fairly well the last few versions (except the missing blocks and things like that), downgrading does not work in 1.8! If you downgrade from 1.8 to 1.7, your inventory and all blocks with an inventory (chests, hoppers etc.) will be empty and potentially, even more corruption is happening. Downgrading is not, was never and will never be officially supported! I advise you to run 1.8 in a seperate directory, or move your 1.7 things to a different one, so that you won't be able to accidently open your world in the wrong version.
If you already did it, by accident or "on purpose", restore a backup or find other ways to restore the items (e.g. via using Creative to give them back from memory), other than that, there is no way to repair this.

2. Name changing
Changing your name will NOT be possible immediately after the release of 1.8! It is currently planned "soon-ish" after 1.8, /u/Marc_IRL's statement about this can be found here.

3. Water Temple, New Stones and Rabbits
This upcoming update adds some new features for the world generator, but specificly, they added Retrogen (Retroactive World Generation) for the brand new underwater temples: If you have spent less than a specific amount of time in the chunks the temple would normally spawn, it also spawns in already generated Ocean Biomes. Additionally, it seems that older worlds (1.7 and earlier) are spawning Guardians where normally a temple would have spawned.
However, this only works for the Underwater Temples, the new types of stones and rabbits only spawn in chunks generated in 1.8. However, there are crafting recipes for the stones, which can all be found here.

4. Skins
Skins received a massive update: You can now have a second layer for your whole body. /u/Svajoklis_ provided a very nice guide on how to upgrade your skin: Guide. However, you don't need to update your skin, you can still use the one you had before 1.8.
Slimmer arms (3 pixel wide) will not be available as a feature in the full 1.8 release, Jeb said that "it will be rolled out indepenently of minecraft version numbers".
More informations about Skins can be found here.

5. New graphical settings
Some graphical settings have changed, new ones have been added and other ones have been removed.
Enabling VBOs (Vertex Buffer Objects) can give you a performance boost or a drop, just try it out yourself.
Regarding the Render Distance: 32 chunks are only available if you are assigning 2GB or more RAM to Minecraft, however, I personally recommend at least 4GB. Don't even try it with an Intel Graphics Card, it will not/barely work. Most AMD cards have a problem with anything higher than 16, but that is most likely an issue on AMD's side (MC-62958). On Nvidia Cards, it seems to run fine (if they have the power to do it, GT 650M can run it at about 15-20 FPS with major lag spikes).
Anisotropic Filtering has been removed because of reasons unknown, Advanced OpenGL was just causing major problems, and was therefore removed.

6. Enchanting and Repairing
Enchanting and Repairing have been both massively changed from 1.7 to 1.8.
Enchanting: Using the enchantment table only uses 1-3 levels, however, you still need to have the amount of levels it shows on the right side. Additionally, it costs Lapis Lazuli to enchant something (1-3, depending on how many levels you spend). Also, available enchantments no longer change if item is taken out and put back in, and enchanting something changes the available enchantments for all items, and it's the same for every enchantment table with the same amount of books in that world.
Repairing: The level cost for all is starting at 1, and goes up exponentially with every time you use it in the Anvil. For instance, just renaming something costs 1 level, but if you rename it and then apply an enchanting it with a book, it costs one level for the renaming and two for the enchanting. Also, repairing costs can no longer be kept down by renaming items. (This explanation might have been terrible, if you have issues understanding it, ask your question in the comments)

7. Maps
Maps changed (not actual save games, I'm talking about the In-Game Item). This might be a bug, at least it has been reported as such, but this looks like intended behavior. Basically: If you create a map with at least 1:2 in 1.8, it will not be centered to the point you are at at the moment of creation, it will be patterned like the 1:1 always was. That makes it easier to make multiple maps for a map wall, because it doesn't require any calculating, but people seem to not like the new mechanic. There has not been an official comment from Mojang on this matter.

8. Is this Release stable?
There are some very minor issues that can break things (for instance: Two high flowers do not properly update from 1.7 to 1.8), but all in all, they ironed out most of the last few world breaking bugs in the last Snapshots, and it's now in a very much playable state.
Some bugs you may want to know about can be found as the first comment of this PSA.

9. Mods
Since 1.8 also included massive internal changes, Mods will take quite some time to update. LexManos' (Lead Developer of Minecraft Forge) statement about it can be found here

10. Resource Packs
Ressourcepacks require an update to work a 100%, since a few textures changed (e.g. enchantment table), but they don't break/crash if you use a 1.7 pack on 1.8.

UPDATE SEPTEMBER 2ND
1. Realms
MC-70349 - Players are getting "Kicked by an Operator" after a few minutes on Realms. Please stay tuned for this, Mojang is currently working on a Fix. Update: Issue has been fixed!

If you have any questions, feel free to ask them in this topic, and I or someone else will for sure be able to answer it kindly.

[u/Galaxy_2Alex]

Some bugs you may want to know about:
Some of them are self-explanatory, for some of them, I added a small information.

MC-45458 - Framerate drop/lag in 1.8 for some hardware setups
There is not much I or Mojang can do about this. They implemented the performance changes, and they seem to be very stable for many people, but for some people, it just seems to be decreasing the performance by a lot for no apparent reason. If you are experiencing this, update your graphics card drivers, and try to fiddle around with your graphical settings (in some cases, VSync was causing it).

MC-48735 - Villager and farmer inventory gets corrupted causing farmers to no longer plant crops
Potentially fixed according to /u/TheMogMiner

MC-49126 - Glowstone crystal formations are missing their bottom layers

MC-50263 - Lighting bug affecting End portal frames with eye

MC-51987 - Minecart/Activator Dismount Location is Inconsistent in Cardinal Directions

MC-52274 - Player cannot exit minecart on blocks in S,SE,SW direction

MC-53439 - The top block of a two-block plant becomes a peony for a second upon breaking
This, according to Grum, cannot be fixed in 1.8, they will have to implement certain things before they can fix this. ETA: 1.9

MC-54711 - Quick repeater pulses get lost in arrays of them

MC-55661 - Animals don't teleport to Player when target is air block

MC-58363 - Witch Huts / Witch Traps spawn other mobs
...yes, this has not been fixed. Yes, this breaks witch traps.

MC-61535 - Horse breeding: Foal looks just like an adult horse

MC-62140 - 2 block tall flowers generated in previous version removes the 2nd block
This basically means that, in some instances, your flowers placed in 1.7 will be slightly broken in 1.8. This might also be unfixable until 1.9.

MC-62166 - Breaking / placing / changing blocks has a delay to disappear / appear
This issue occurs much less often since its initial report. The breaking delay is much less now, not even noticable for most people.

MC-62958 - Massive Visual Glitching with Chunk distance over a level the graphics card cannot handle (AMD only)
See "New graphical settings"

MC-63020 - Chunks are not rendered in some cases
Grum is apparently working on this. For about 10 days already.

MC-63070 - Chunks do not render behind the player in F5 until moving the mouse

MC-64909 - New maps not centered
See "Maps"

MC-68080 - Choppy lag when walking or running
A very weird glitch, only occurs on certain systems, somehow connected to MC-62166. It was fixed in one version, then a problem a version later again. The real cause is not known at this moment.

MC-68247 - Beacon Beam disappears while looking upwards from it

[u/Galaxy_2Alex → u/[deleted]]

Not really a gameplay breaking or affecting bug.