I think fences are a remarkable item. Such a simple concept, yet they have so many uses. I'd like to expand these uses even further with a number of changes and additions detailed below.
Fences should connect to adjacent walls
(Update 9/29: Fences now connect to adjacent walls, but it is automatic and the player has no control over it. We'll have to wait and see if this is a burden to players, or if it works well enough.)
Right now fences only connect to other fence pieces, meaning if you have a fence butting up against a wall, there will be a small gap between the last fencepost and the wall. Although functionally the fence is still sound as it is technically solid all the way to the wall, the appearance of the gap makes the fence look incomplete. However, people sometimes place fence posts next to walls without intending for them to connect, such as for a support beam or lamp post. I therefore suggest that fences be able to connect to adjacent solid blocks using one of these three methods:
1. In a similar fashion to torches, the block that is highlighted when the fencepost is placed will determine whether or not the fence connects to an adjacent block. As shown in Figure 1 below, where the pink dotted line represents the highlighted block, placing a fence while looking at the ground will not connect it to anything, whereas placing it while looking at a block will attach it to that block.
*Foreseeable problems: fences should probably still automatically connect to other fence blocks regardless of placement, so new players may be confused as to the rules of placement-dependent connections and which blocks it applies to. Also, this method limits fences to only being able to connect to one block at a time.
2. Fences will automatically connect to any and all adjacent solid blocks only when connected to another fence piece, as illustrated in Figure 2 below. This would allow players to place single fence posts next to walls, even stack them on top of each other, without having them connect to the wall.
*Foreseeable problems: though ideal for most situations, this might limit the creativity of players as they would have little control over it. If players wanted a single post to be able to connect to one or more walls, such as in a 1x1 window, they would not be able to.
3. Fence posts would automatically connect to adjacent solid blocks when placed next to one, but not when blocks are placed next to them, or vice versa.
*Foreseeable problems: constantly removing and replacing blocks to get fences to connect or not connect properly may become tedious.
Fences should be able to link diagonally
(Update 9/29: Now that the collision models match the visible models of fences, posts placed diagonally can be slipped through. I believe diagonal linking is now even more important, since nobody wants jaggedy fences.)
Pretty self-explanatory. Fences should be able to link diagonally with other fences on the ground as if they were directly next to each other. I think fences should also be able to link diagonally upwards with fences one block above them; Figure 3 below shows how this works, as well as how they might also link to adjacent walls using one of the methods above while connected diagonally to another fence.
Fences should be placeable on half-blocks
Though the model and very name of a half-block makes it seem they only take up half a block, half-blocks actually occupy one entire block in terms of block placement. The game is not designed to think of things as halves of a block, and it is for this reason that nothing is placeable on top of half-blocks. However, I believe that with a bit of clever programming, items like torches and fences can be made to be placeable on top of half-blocks without dividing whole blocks of space into halves. Figure 4 below shows fences placed on whole and half-blocks (connections not shown), and the green dotted line shows the blocks of space that the fences occupy. As you can see, though the fence appears to be placed halfway inside the half-block's block of space, it actually occupies the block directly above it. Its model is offset, similar to how the model of tall grass is offset to make it appear to intersect multiple blocks when it only exists in one.
The orange dotted line in Figure 5 shows the collision model for each fence, which is one and a half blocks in height, and how it behaves with half-block fences.
Fences on stairs (maybe)
I'd like fences to be able to be placed on stairs as well. Put them next to a staircase and they can serve as a banister. They be placed just like they are on half-blocks (mentioned above), but stairs pose a unique problem in that the stair dips in the middle of the block right where the fencepost is supposed to go. The model could potentially be changed so that one fencepost becomes two when placed on stairs so that each post sits on a step, but they would not line up properly with any fenceposts placed above them (if for instance somebody built a roof above an outdoor staircase with supports connected to the railing). Though it's a bit awkward, the only solution I can really think of is just to slap the post in the middle of the block so that it rests on both steps, as in Figure 6 below.
Fences should be able to be placed on the sides and undersides of other blocks
(Update 9/29: Update notes say "Fences can be placed like normal blocks," which I assume fulfills this suggestion.)
No image for this one, and again pretty self-explanatory. It's great that we can put fences on top of other fences now without having to make a dirt pillar first, now please allow us to do it in reverse.
Fences of different materials
Lastly, but not leastly, I'd like fences to be craftable not just out of wood but of iron and various types of stone as well. "Stone fences?" Well, yes, they wouldn't really be fences though, more like stone balusters. All of the rules above would apply to these new fences as well, obviously. Figure 7 shows a design for an iron fence, and Figure 8 shows a few possible designs for stone fences. There would presumably also be iron fence gates, but probably not stone ones.
Well we have iron gates (iron bars) which are like iron fences, but I think there should be the stone one and I like the other two ideas as well.
I honestly did not do my research here and didn't realize iron bars worked like fences. I had hoped actual iron fences could just replace iron bars, but I suppose they work just as well, although I might ask Notch to get rid of the weird cross-linking bars in the texture. It'd also be nice to have an iron pole when one bar is placed down, similar to the fencepost, instead of the cross-shaped object we have now.
I am the bone of my sword
Steel is my body, and fire is my blood
I have created over a thousand blades
Unknown to death, Nor known to life
Have withstood pain to create many weapons
Yet, those hands will never hold anything
So as I pray, Unlimited Blade Works
Awesome idea. I agree with everything here. The railing on stairs would have to be purely for visual appeal, since you can't walk in a fence block, but I'm sure many would use the feature to their advantage.
But i don't understand your forseen problems, regarding this suggestion, since new players are always confused when playing this game for the first time, and discovering the game is only 1 cool aspect of minecraft, and i honestly don't understand why you say they can only attach to 1 block/fence at a time.
While it's true that learning the ins and outs of the game is a step every new player has to take, a goal is to make it as simple and intuitive as possible to make learning easy without limiting what can be done with it, which brings me to your second point: if fences connect to blocks they're placed on, they can only be connected to that block, since you obviously can't point the cursor at multiple blocks at once (unless, of course, it was made so the fence would connect to all blocks around it when placed on a wall).
Was checking my backlog of unviewed Twitter, and...GOOD NEWS
Well damn, thanks for the update. I hope this works out well, as it was a concern stated in my OP that fenceposts are often placed next to walls without the intent for them to connect, but we'll have to see.
I do think more materials, but also spiked fences, that cause damage on collision (maybe only with the top) would be a nice edition. Or possibly redstone-transmitting fences.
As for gates, the biggest thing is that people would like them to work properly when stacked. Personally, if not have them work with redstone by default, I'd like to be able to build a "redstone enabled" gate. Also, different gates for different fences?
Okay, i see what your saying, but i think that if fences naturally attach to each other, unless the user points straight to the ground (like when placing a torch), this problem would seize to exist, or at least be diminished AND it would contribute to new criative designs (where fence poles can be next to each other and not connect)
This is a possibility, but I'm worried that would be even more confusing. People who are used to just putting things on the ground may wonder why their "fences" are just a bunch of posts in the ground.
They should be just like doors, place one and it open normally to one side, or place 2 adjacent to each other, and they open like...well, doors. like the western bar doors.
I personally kinda like the way they are now. That's just my opinion though. Also, no, I haven't noticed the texture change to iron bars.
I do think more materials, but also spiked fences, that cause damage on collision (maybe only with the top) would be a nice edition.
Would look neat, but I don't think it would be very useful. The only monsters that can actually scale fences are spiders, and one poke would do little to actually deter them.
As for gates, the biggest thing is that people would like them to work properly when stacked. Personally, if not have them work with redstone by default, I'd like to be able to build a "redstone enabled" gate.
No real reason for them not to work with redstone. Also little reason for them not to connect and open together when stacked. Think I should add those to the OP?
Also, different gates for different fences?
Yes, but metal and wood gates are really the only ones that make sense. Any other fences would be made out of different types of stone, and moving parts of stone do not work well.