[MC-12456] Fences won't attach to layered snow blocks

Fences attach to a full snow block as they do with other blocks, but if you create a full snow block using the layered snow, when the block is full, the fence will not attach. Not sure if the fence will attach after a block update, or if it will just stay "detatched".

(PS. Sorry for my bad english, I'm Italian 😛)
(Look at the image for a better explanation)

Possible explanation: I think that when a "group" of snow layers becames a "full" snow block (When the block is tall as a normal snow block) the neighbor blocks are not updated, so, if the fence is not updated, it will not attach. Not sure about this, just a theory.

Linked issues

relates to 1

MC-8797 8-level flat snow does not act like a snow block Resolved

Attachments

Comments 15

Chris Dusto 2013-03-20T17:58:16Z

Snow layers are not blocks, they are children of the block they are sitting on top of.

I'd consider this invalid, as there is no reason why the fence would attach. Possibly this is a feature request? There is a forum for that, but I don't have the link on me.

KeeZeeK 2013-03-20T18:03:31Z

I think that the layered snow block should act like a normal snow block. When I say "layered", I mean a full snow block created with 8 snow layers. So, if the layered snow block should act like a normal snow block, why the fence won't attach?

This is not a feature request, this is just something strange: the block won't do what it have to do.

bugi74 2013-03-20T18:19:24Z

Related to MC-2938 and its relateds...

However, it indeed might be better if fences do not connect snow (normal or layered full). I mean, snow is supposed to rain sometime, why would the fence suddenly decide to change and connect to that snow block.

(Then again, if the snow was semi-permanent (like in some cold places), one could build fences in that way. Unfortunately, Minecraft can not differentiate with the cases, and must choose either one. Edit: oops, it can probably detect the difference between normal snow block and one consisting of layers...)

Chris Dusto 2013-03-20T18:55:30Z

@Markku
Only related if the problem persists after preforming a block update on the snowstack and trying again. I'd stray away from a relationship.

@KeeZeeK
If you are saying that it 'should' act that way (as in it would be a good idea for it to), it is a feature request. If you are saying that it 'should' act that way (as in it is the intended behaviour), you are incorrect. The snow layers are part of the block underneath them, and do not form a new block. This is intended, as 8 visual layers are 7 layers of actual behaviour, while a snow block would act as 8 layers of actual behaviour.

EDIT: Go stand on top of the 'block' and dig downwards with a shovel. Does the block get destroyed as a single object, or as 8 layers of snow?

bugi74 2013-03-20T19:03:57Z

Chris:
1. The "attachment" of fence to neighbor block is made at rendering time; it does not require updates. Thus, if it is deemed that the fence should connect to such block, the issue is indeed related. (This didn't consider at all whether the full layers of snow is a block or not, though.)

2. Someone saying "should" is pretty much equal to "expected", and the instructions already tell to use that "expected". Only Mojang can say whether something is or is not "intended behavior" (though sometimes moderators do wield this power...). Even if the snow layers were not an own block, Mojang could intend the fences to connect to it (at least if they connect to normal snow block); at least in such case it would not make sense to players if there was a difference. Technical background details are rarely a good reason to claim something that makes no sense to be intended (although it does happen, sometimes for good reasons..)

3. "The snow layers are part of the block underneath them, and do not form a new block."
Where did you get that idea from? As far as I can tell, by reading the source code, the snowlayers are their own block (by type id 78), storing the snow height in its metadata (in 3 LSBs). I recommend looking at ItemSnow.func_77648_a() (the only larger method in that class).

5 more comments

kumasasa 2013-03-20T20:56:07Z

8 layer snow blocks behave different as a regular snow block, see Dinnerbones comment in MC-8797

bugi74 2013-03-20T21:24:33Z

Naturally, I'll take that as a challenge to fix the multiple issues mentioned in that MC-8797 (looks somewhat doable, and if it gets kinkier, I'll possibly see combining the fix for attaching torches to stairs' backsides), and then this issue (but just as an example, not as a fix, since I'm not so sure this one should be intended).

Anon Ymus 2013-03-24T02:28:01Z

Confirmed in 1.5.1. It has nothing to do with updates, just that the snow tile of any layer is still considered one layer thick for many things.

bugi74 2013-03-24T11:50:38Z

Actually, it does return proper "size", but there are couple other methods that, in their current form, can not check the particular block in the world and always work as if there was a single possible shape/state/orientation for that block type. This fundamental "issue" is the reason behind problems with backsides of stairs, these growing snow layers, half-blocks, etc.

For example, even if the snow layer block would be "full", the method "isOpaqueCube" (or something like that, typing out of memory) returns always false. A lot of other functionality depends on that particular value (light, attaching other items, etc.).

As can be seen in my fixes for the stairs, the solution is to add another method which takes a world/blockaccess object and the block coordinates, so that the particular block can be handled properly. However, depending on the case, this may add some more workload. For this snow layer block case, it should not be too much (as the values are not checked all the time).

Preliminary look on the case makes me think fixing this indeed requires same/similar approach as in the stairs-issue. Unfortunately, due to other things I've had on my hands, I haven't had time to work on this more, and I estimate I won't have enough time for a week more.

Also, I had it slightly wrong with the "not require updates". Seems rendering is implemented so that the visuals do not change until the chunk (16x16x16) has received some update which triggers re-rendering, or player leaves and returns the rendered area, or any other reason that requires re-rendering.

KeeZeeK 2013-03-29T13:27:37Z

Well, this is related to that bug, but what I meant with "it should act like that" was "the layered snow should act as the normal snow". just this 😉

bugi74 2013-04-03T19:48:32Z

I understood that. I mentioned the relation because the reason for both issues is based on the same thing(s) of the current code (or more accurately, lack of the same thing(s)).

(And unfortunately, I seem to keep getting more other urgent things on my hands...)

Itouch2 2014-04-21T12:54:55Z

Confirmed for 1.7.5, 1.7.9, 14w11

Daniel Smith 2014-07-30T18:09:29Z

Just my opinion, but I like having the option to have non-connecting snowblocks that otherwise look identical to regular snowblocks. Perhaps this should be kept as a feature for mapmakers rather than labeled as a bug. Because anyplace you could use 8 snow layers as a solid block, a regular solid block will do just as well.

bugi74 2014-07-31T16:37:17Z

Daniel Smith, such option would be nice, but it should be available consistently for all blocks, not just snow. Keeping around (apparent) inconsistencies like this only make things worse in the long run. Instead, Mojang should add a feature that allows the fences to be connected or disconnected to neighbor blocks as wanted, or at least a limited version where player could choose that a fence only connects to other fences vs. to all blocks that look suitable to connect to. The latter solution would not need extra memory, but either new block type or one meta-bit..

Daniel Smith 2014-08-01T00:43:13Z

Re: Markku

Consistency is overrated in the world of Minecraft though new features and functionality are not. The Mojang way of doing things has always been to implement new and unique behaviors for each addition to the game to maintain variety. This situation certainly seems to qualify - a way to build using snow that doesn't connect with fencing. So, while I understand the elegance of your solution, I suggest your comment be rephrased as a feature request and posted in the appropriate place rather than continue it here. I think there would be strong support for the ability to connect/disconnect fencing to neighboring blocks. A simple right-click per fence post with the default being connected should be easy to implement.

I think the simplest solution for the problem in this thread would be to eliminate the 8-layered snow block all together. Instead, when a 7-layered snow block is left-clicked with a snow layer, the 7-layer block should be replaced with a full snow block. This would eliminate the problem in the first place since fencing already connects correctly to normal snow blocks.