[Vanilla Bug] The great cow escape!

[Delerium76 3]

For some reason my cows keep escaping their pens.  I'm guessing it might be due to the varying size mechanic, not sure.  For the time being, I blocked them in with wooden walls, although it's ugly and feeding them is a pain, it prevents the escape.

[Kittychanley 1,002]

This is a vanilla bug. Mobs glitch through fences. It doesn't matter if it's a TFC cow or a vanilla cow, they will both do it.

 

https://bugs.mojang.com/browse/MC-10

[Delerium76 3]

odd, I never encountered them actually escaping the pen until TFC. I've seen that glitch described in that post, but for me they just "glitched" like a phantom, but stay inside.  Also, it was 2 cows with a 3x3 space to roam, so they aren't exactly being pushed like that post described.

[Kittychanley 1,002]

The mob doesn't have to have been pushed. What happens is that the animal is occupying the same block coordinates (X, Y, Z) as the fence block. The animal doesn't take suffocation damage, because the block is transparent, and they are able to move closer to the center of the block because of the fence's small hitbox. When the chunk unloads, and then reloads, Minecraft sees that there is a mob, and a block occupying the exact same space, so it tries to correct it by moving the animal to the nearby block. However, the game has no idea which nearby air block is "inside" the fence, and which one is "outside" the fence. It just picks one at random. Sometimes this means the animal is teleported back into the pen, and other times it means the animal is teleported outside of the pen.

[Terex 108]

To me, this problem feels less severe in 1.7.10 than in 1.6.4. However, I don't know if Mojang are working on it or not.

[Bunsan 323]

The only thing that may have changed is mob AI to try and reduce the time they spend bumping up to fences.

[micmastodon 41]

I haven't seen this bug in vanilla in quite some time. Even with hundreds of animals on multiple servers I don't think I've seen a single animal glitch through a fence in vanilla  1.7. I would venture to say that if it's happening in TFC, that there's probably something going on in TFC that's bringing it back.

 

Clearly the "bug" is with vanilla MC, but it would seem Mojang have found a work-around, maybe with the AI, to keep it from happening or to make it vanishingly rare. Could there be something in the TFC code that negates the work-around?

[Kittychanley 1,002]

This bug is not "vanishingly rare" in vanilla. In vanilla 1.8, keep a couple of bunnies and chickens in a fenced in area. Within a few times of loading and unloading the area, at least one or two of the animals will have escaped.

[CHeuberger 9]

I haven't seen this bug in vanilla in quite some time. Even with hundreds of animals on multiple servers I don't think I've seen a single animal glitch through a fence in vanilla  1.7. I would venture to say that if it's happening in TFC, that there's probably something going on in TFC that's bringing it back. Clearly the "bug" is with vanilla MC, but it would seem Mojang have found a work-around, maybe with the AI, to keep it from happening or to make it vanishingly rare. Could there be something in the TFC code that negates the work-around?

I definitively had/have this happening with 1.7.2, still before I started playing TFC. I got lots of pigs an cows and from time to time, that is, when I return from a longer trip, one or two of them "escapes". I have a second fence around everything to catch these...Haven't updated to a higher version since getting out of boats is a pain after 1.7.2.

[micmastodon 41]

I stand corrected! I guess I'm just lucky because I honestly can't remember this happening at all in the past year in vanilla. I thought it had mostly become a non-issue.

[Udary 20]

My rule is, don't use fences as animal enclosures. Use walls: if you want to see through it, use glass; if you want to see into it, sink it in the ground.

 

I ALWAYS get chickens stuck in the corners of fenced areas, so unfortunately my chickens live in a small wooden box. Sorry, chickens.

[CHeuberger 9]

I just dig a 2 deep 5x5 (increased if needed) hole.A bit strange but it can be build very early in the game, no tool needed (maybe a stone shovel for speed).When I got material and time I put a fence around it so no other animals/monsters can get in, and a stair to get out myself.Before 0.79 I'd build a stall with a combination of walls and double fences:

This also worked fine

[RhaeStarShine 2]

What has always worked for me is to put the fence on top of a solid block. The animals see the fence on top of that as a block so they have never tried to jump onto it, so they don't bump into fences, the fence or second high block is transparent so they don't suffocate. And it looks pretty good in my opinion. 

 

[damnedsky 0]

This is getting annoying... I listened to your advice guys and made a full glass enclosure. Here is a picture with my case: 

Spoiler

The pigs bounding box is much greater than the pig itself and they space themselves around so they don't touch. It might not seem from the image but this is a PACKED enclosure. There are pigs being pushed into the glass as you can see in the left wall and far right. Fortunately for me I only had 3 pregnant female pigs...

[Teagan75 14]

You have to give your animals more space.....this is a vanilla bug that shows up more in TFC because this mod makes you explore great distances for resources