Daniel King
Comments
I placed a bunch of sheep around me, trying to place them a little south east of where I was standing at the origin. I left it on while I was gone from home for 6 hours and got the picture NWtrend as my result.
I think this bug is clearly confirmed and in 1.6.2.
Just to quantify this, in each quadrant I had the given number of sheep
Northwest: 12
Northeast: 3
Southeast: 0
Southwest: 4
That is based on the sheep which were rendered in the overhead picture. There were some not pictured.
If you play for any extended period of time I think this is very, very noticeable.
@ANBO Motohiko
No, that is a problem with core path-drawing methods, explained in MC-21109, which honestly is the same problem as MC-12427 and MC-4661 (which have the same cause in the code), but explained in more detail for more situations. In that bug, an entity is trying to path from inside a fence. In this bug the random destinations animals choose to move in tend to be weighted northwest of it. Both bugs are annoying and should be fixed however.
I have had animals swim off , to (from kilometers away), and past my island home following a northwest path. By and large it seems all the animals in my world migrate northwest unless I enclose them. Actually, if you look at large animal enclosures you can see a slight northwest bias. I hope this gets fixed as it is an annoyance when you have lived in an area a long time. Good work.
@Kumasasa
You are somewhat right. Actually, the exact source for this (and MC-4661) is explained in a separate bug report I made (MC-21109) which encompasses quite a few different issue all caused from the same flaw that pathfinding is heavily grid-based while movement is not. It is not one little bug but rather a conceptual flaw in the coding that sometimes mobs can pathfind when they cannot move somewhere and cannot pathfind when they can move somewhere. Obviously, whether a mob thinks it can move and whether it can move should always agree. The reason no mobs (including large ones) can pathfind out of northwest corners is because their pathfinding algorithm begins pathfinding from the block which contains their minimum x and z bounding box coordinates. Then, beginning from inside the fence block, they pathfind in a totally grid-based way and conclude their only possible paths lead through the fence they are stuck against.