At this point, if you circumvent the restriction and open a 1.16 world in 1.17, yeah, old worldgen areas got air under bedrock and can be accessed from new gen chunks.
Anyones guess how conversion will work at release. But I highly doubt they will leave it like it is now.
Potential solution 1, any chunks generated pre 1.17 will be filled with bedrock from Y 0 to -64
Potential solution 2: for any old worldgen chunk, it will generate 0 to -64 using 1.17 and add it under existing bedrock.
Potential solution 3: same as 2 except the replace pre-existing bedrock with new gen as well.
Good luck for developers making this work without sending players straight into the void in survival.
I doubt it will happen for already generated chunks in 1.16 or earlier.
What I am predicting in the finished version is you'll have a big wall of bedrock stretching down from Y 0 to Y 5 to negative 64 at the edge of the old chunks, and then all newly generated chunks from that point on will have their bedrock layer moved to negative 60 to 64.
The only non destructive way that old chunks could have their bedrock layer moved is if the game was coded very carefully to make sure terrain generated normally from Y 0 down to the new bedrock layer, and that bedrock at the old region was wiped from existence to let players access the new terrain.
If old chunks are to be expanded later on safely, if not in 1.17, but updates beyond this, then bedrock would probably still exist at Y 0 to Y 5 in the old chunks, but players would need to go to a different area to access the terrain below.
If there is any hope of introducing it to old chunks safely, whatever happens, the void mustn't be accessible in survival mode except in End dimension.
Chunk errors are serious business and can break a players world permanently.
I'm no expert but I don't think they can modify existing chunks with an update, non-destructively anyway.
If they do anything I might expect new chunks to have bedrock walls below 0 on the sides bordering old chunks.
But they haven't said anything about it so who knows?
It is certainly possible to add new features to existing chunks - in fact, this has been done since 1.8, which can generate ocean monuments in existing chunks. One way to do this I'd fill in the lower 64 layers and replace existing bedrock with stone, then run the usual world generation steps to add caves/ores/etc but limit it to below y=0, which is all very easy to do thanks to the "version" tag that has been saved with chunks since 1.9 (i.e. any chunk that does not have a version corresponding to 1.17 or later will be updated), and this really isn't even as difficult as having to update entire chunks to entirely new data formats, as was done in 1.13, with many other recent versions making major changes to data structures (this is why downgrading from e.g. 1.16 to 1.15 will reset all loaded chunks).
I even did something similar in my own double/triple height terrain mods, except it was applied during initial chunk generation - I generated terrain as usual then lifted it up by 64 or 128 layers with the space below filled in with solid stone and a layer of bedrock (normal bedrock was omitted), the main difference was that since this was during initial chunk generation I didn't need to make sure no features were generated where they shouldn't (e.g. caves cutting through your base); in this regard perhaps an easier solution for 1.17 is to generate new 1.17 chunks and merge them with old chunks by copying the old chunk, with bedrock replaced with stone, over the upper part of the 1.17 chunks, then the game doesn't need to restrict feature generation at the cost of slower world conversion (in either case the "optimize" feature can be used to convert an entire world all at once so this doesn't impact normal gameplay).
It is certainly possible to add new features to existing chunks - in fact, this has been done since 1.8, which can generate ocean monuments in existing chunks. One way to do this I'd fill in the lower 64 layers and replace existing bedrock with stone, then run the usual world generation steps to add caves/ores/etc but limit it to below y=0, which is all very easy to do thanks to the "version" tag that has been saved with chunks since 1.9 (i.e. any chunk that does not have a version corresponding to 1.17 or later will be updated), and this really isn't even as difficult as having to update entire chunks to entirely new data formats, as was done in 1.13, with many other recent versions making major changes to data structures (this is why downgrading from e.g. 1.16 to 1.15 will reset all loaded chunks).
I even did something similar in my own double/triple height terrain mods, except it was applied during initial chunk generation - I generated terrain as usual then lifted it up by 64 or 128 layers with the space below filled in with solid stone and a layer of bedrock (normal bedrock was omitted), the main difference was that since this was during initial chunk generation I didn't need to make sure no features were generated where they shouldn't (e.g. caves cutting through your base); in this regard perhaps an easier solution for 1.17 is to generate new 1.17 chunks and merge them with old chunks by copying the old chunk, with bedrock replaced with stone, over the upper part of the 1.17 chunks, then the game doesn't need to restrict feature generation at the cost of slower world conversion (in either case the "optimize" feature can be used to convert an entire world all at once so this doesn't impact normal gameplay).
This is a different issue than generating structures on top of existing chunks, which is not likely to kill a player.
If somebody is at bedrock it would be bad for them to then end up in the void if this feature went wrong.
I would recommend Mojang make the world conversion optional, with a prompt that warns the player that there is a chance this would happen and before the conversion starts, to automatically backup the world just in case.
I'm not doubting that it is possible, it's just risky.
If you spawned inside a wall inside a structure, but had a pickaxe equipped, you have a chance to escape, even underwater if you got Aqua Afinity or potions of water breathing, for example.
If you fall in the void, you're screwed.
When players have just spawned back into a world they don't have time to go and make potions of slow falling
I'm no expert but I don't think they can modify existing chunks with an update, non-destructively anyway.
If they do anything I might expect new chunks to have bedrock walls below 0 on the sides bordering old chunks.
But they haven't said anything about it so who knows?
Well, They could add a tag to say "this is the cave update" for each new chunk and then replace all bedrock bellow Y 10 (to make sure no bedrock builds get destroyed) with the grim stone and generate only the grim stone area for those chunks.
Well, They could add a tag to say "this is the cave update" for each new chunk and then replace all bedrock bellow Y 10 (to make sure no bedrock builds get destroyed) with the grim stone and generate only the grim stone area for those chunks.
They'd still need to modify existing chunks so that in survival play the void is impossible to access in Overworld.
However developers have been able to safely modify existing chunks before
Think Xbox 360 edition worlds being converted to Xbox One, and then bedrock edition
You could safely access the additional generated chunks on X and Z coordinates without falling into the Void
the same principle could apply with 1.17 update, but on the Y coordinate instead.
All air blocks and bedrock between Y negative 60 to Y 0 could be converted to general terrain (deepslate, stone, diorite, andesite, granite, dirt, gravel etc) but bedrock at Y -64 could still generate and prevent all access to the void.
Technically they have been able to extend existing chunks before, and in a way that doesn't destroy people's worlds.
Well, That was just transferring save data for the first "conversion" and the second one was creating a new copy of the world and was only reading chunks and saving them in a new format as a separate copy in the copy world. The save system already safely modifies chunks without corruption and programs like world edit do not corrupt worlds.
Well, That was just transferring save data for the first "conversion" and the second one was creating a new copy of the world and was only reading chunks and saving them in a new format as a separate copy in the copy world. The save system already safely modifies chunks without corruption and programs like world edit do not corrupt worlds.
They can still use a similar method to convert 1.16 worlds to 1.17 and generate the newer terrain, mineshaft and cave systems in existing chunks.
on Xbox 360 worlds it was impossible to break through the barrier at X or Z 864 blocks, so was effectively the same as bedrock layer.
When converted to Xbox One edition worlds, it generated more chunks beyond Z or X 864 and you could travel toward them without issue.
Mojang could make and use a save file conversion system to generate more terrain below Y 0 on existing chunks on player worlds from version 1.16 or older.
It is not impossible for them to do, that is the point.
With world conversion the game would be coded to recognize older chunks and be able to update them to the newer world type.
They don't have to take the lazy route and just make a bedrock wall at older chunks between Y 0 to negative Y 64.
Example: You are in a 1.16 generated chunk where bedrock is at y = 0. A few chunks over is 1.17 generated chunks where bedrock is at y = -56.
If you tunnel over from the 1.17 chunks into the 1.16 chunks will building below that bedrock be possible, or does no one know right now?
At this point, if you circumvent the restriction and open a 1.16 world in 1.17, yeah, old worldgen areas got air under bedrock and can be accessed from new gen chunks.
Anyones guess how conversion will work at release. But I highly doubt they will leave it like it is now.
Potential solution 1, any chunks generated pre 1.17 will be filled with bedrock from Y 0 to -64
Potential solution 2: for any old worldgen chunk, it will generate 0 to -64 using 1.17 and add it under existing bedrock.
Potential solution 3: same as 2 except the replace pre-existing bedrock with new gen as well.
I'm no expert but I don't think they can modify existing chunks with an update, non-destructively anyway.
If they do anything I might expect new chunks to have bedrock walls below 0 on the sides bordering old chunks.
But they haven't said anything about it so who knows?
Good luck for developers making this work without sending players straight into the void in survival.
I doubt it will happen for already generated chunks in 1.16 or earlier.
What I am predicting in the finished version is you'll have a big wall of bedrock stretching down from Y 0 to Y 5 to negative 64 at the edge of the old chunks, and then all newly generated chunks from that point on will have their bedrock layer moved to negative 60 to 64.
The only non destructive way that old chunks could have their bedrock layer moved is if the game was coded very carefully to make sure terrain generated normally from Y 0 down to the new bedrock layer, and that bedrock at the old region was wiped from existence to let players access the new terrain.
If old chunks are to be expanded later on safely, if not in 1.17, but updates beyond this, then bedrock would probably still exist at Y 0 to Y 5 in the old chunks, but players would need to go to a different area to access the terrain below.
If there is any hope of introducing it to old chunks safely, whatever happens, the void mustn't be accessible in survival mode except in End dimension.
Chunk errors are serious business and can break a players world permanently.
It is certainly possible to add new features to existing chunks - in fact, this has been done since 1.8, which can generate ocean monuments in existing chunks. One way to do this I'd fill in the lower 64 layers and replace existing bedrock with stone, then run the usual world generation steps to add caves/ores/etc but limit it to below y=0, which is all very easy to do thanks to the "version" tag that has been saved with chunks since 1.9 (i.e. any chunk that does not have a version corresponding to 1.17 or later will be updated), and this really isn't even as difficult as having to update entire chunks to entirely new data formats, as was done in 1.13, with many other recent versions making major changes to data structures (this is why downgrading from e.g. 1.16 to 1.15 will reset all loaded chunks).
I even did something similar in my own double/triple height terrain mods, except it was applied during initial chunk generation - I generated terrain as usual then lifted it up by 64 or 128 layers with the space below filled in with solid stone and a layer of bedrock (normal bedrock was omitted), the main difference was that since this was during initial chunk generation I didn't need to make sure no features were generated where they shouldn't (e.g. caves cutting through your base); in this regard perhaps an easier solution for 1.17 is to generate new 1.17 chunks and merge them with old chunks by copying the old chunk, with bedrock replaced with stone, over the upper part of the 1.17 chunks, then the game doesn't need to restrict feature generation at the cost of slower world conversion (in either case the "optimize" feature can be used to convert an entire world all at once so this doesn't impact normal gameplay).
TheMasterCaver's First World - possibly the most caved-out world in Minecraft history - includes world download.
TheMasterCaver's World - my own version of Minecraft largely based on my views of how the game should have evolved since 1.6.4.
Why do I still play in 1.6.4?
This is a different issue than generating structures on top of existing chunks, which is not likely to kill a player.
If somebody is at bedrock it would be bad for them to then end up in the void if this feature went wrong.
I would recommend Mojang make the world conversion optional, with a prompt that warns the player that there is a chance this would happen and before the conversion starts, to automatically backup the world just in case.
I'm not doubting that it is possible, it's just risky.
If you spawned inside a wall inside a structure, but had a pickaxe equipped, you have a chance to escape, even underwater if you got Aqua Afinity or potions of water breathing, for example.
If you fall in the void, you're screwed.
When players have just spawned back into a world they don't have time to go and make potions of slow falling
and fetch chorus fruits.
Well, They could add a tag to say "this is the cave update" for each new chunk and then replace all bedrock bellow Y 10 (to make sure no bedrock builds get destroyed) with the grim stone and generate only the grim stone area for those chunks.
They'd still need to modify existing chunks so that in survival play the void is impossible to access in Overworld.
However developers have been able to safely modify existing chunks before
Think Xbox 360 edition worlds being converted to Xbox One, and then bedrock edition
You could safely access the additional generated chunks on X and Z coordinates without falling into the Void
the same principle could apply with 1.17 update, but on the Y coordinate instead.
All air blocks and bedrock between Y negative 60 to Y 0 could be converted to general terrain (deepslate, stone, diorite, andesite, granite, dirt, gravel etc) but bedrock at Y -64 could still generate and prevent all access to the void.
Technically they have been able to extend existing chunks before, and in a way that doesn't destroy people's worlds.
Well, That was just transferring save data for the first "conversion" and the second one was creating a new copy of the world and was only reading chunks and saving them in a new format as a separate copy in the copy world. The save system already safely modifies chunks without corruption and programs like world edit do not corrupt worlds.
They can still use a similar method to convert 1.16 worlds to 1.17 and generate the newer terrain, mineshaft and cave systems in existing chunks.
on Xbox 360 worlds it was impossible to break through the barrier at X or Z 864 blocks, so was effectively the same as bedrock layer.
When converted to Xbox One edition worlds, it generated more chunks beyond Z or X 864 and you could travel toward them without issue.
Mojang could make and use a save file conversion system to generate more terrain below Y 0 on existing chunks on player worlds from version 1.16 or older.
It is not impossible for them to do, that is the point.
With world conversion the game would be coded to recognize older chunks and be able to update them to the newer world type.
They don't have to take the lazy route and just make a bedrock wall at older chunks between Y 0 to negative Y 64.