**** infomation about how to see maps ****
about marker which be showed on maps
here, the Circumference of 3-sphere is dfined as 2π.
when measuring from front of the player,
if the distance between the player and a object is in range of 0~π/2,
marker of the object has shape and color like below:
similarly, if a distance is in the range of π/2~π, like below:
similarly, if a distance is in the range of π~3π/2, like below:
similarly, if a distance is in the range of 3π/2~2π, like below:
single/dual map mode
in single map mode, all kinds of marker is showed on the one map.
in dual map mode, two X-shape marker is showed on one map.
and two cross-shape marker is showed on another map.
front map/bird's-eye map
map with blue line and red line is front map.
object upper than the player is showed on upper side of map.
similarly, lower one is on lower side.
right one is on right, left one is on left.
map with yellow line and red line is bird's-eye map.
object in front of the player is showed on upper side of map.
similarly, back one is on lower side.
and right one is on right, left one is on left.
