Minecraft – Chunk Loading glitches

Here is the relevant piece of code from the Minecraft source:

EntityPlayer entityplayer = worldObj.getClosestPlayerToEntity(this, 16D);
        if(entityplayer != null && canEntityBeSeen(entityplayer))

This means that the range of sight is 16 blocks; however, there's also something funny. For one, if there is a closer player than you, but they can't be seen (for example, if the closer player is behind a wall), then the mob won't notice you.

Additionally, the ghast uses a separate method including:

worldObj.getClosestPlayerToEntity(this, 100D);

So it will see you 100 blocks away.

It is static -- no closer than 24 meters from the user, no farther than 144 meters.

To be crystal clear:

. 8×4 meters area eligible for spawning
X Your position

....................................
....................................
....................................
....................................
....................................
....................................
.................. .................
..............         .............
.............           ............
............      X      ...........
.............           ............
..............         .............
.................. .................
....................................
....................................
....................................
....................................
....................................

I got the above, sans X, with

x = [["." if (i**2+j**2)>24**2 else " " for j in range(-72,72,4)]
                                        for i in range(-72,72,8)]
print "\n".join("".join(line) for line in x)