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
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............ X ...........
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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)