pika-zoo

The original Pikachu Volleyball (対戦ぴかちゅ～　ﾋﾞｰﾁﾊﾞﾚｰ編) was developed by

• 1997 (C) SACHI SOFT / SAWAYAKAN Programmers
• 1997 (C) Satoshi Takenouchi

All of the code for pika-zoo was written based on gorisanson/pikachu-volleyball

Differences from the original code

• Random numbers are generated by the environment's numpy generator (self.np_random), not by the global function rand.js of the original code.
• Some code logic has been improved for faster iteration.
  • #5

You can play the game at the site below.

• https://gorisanson.github.io/pikachu-volleyball/en/
• P2P Online : https://gorisanson.github.io/pikachu-volleyball-p2p-online/en/

rl-video-step-0.mp4

Import	from pikazoo import pikazoo_v0
Actions	Discrete
Parallel API	Yes
Manual Control	No
Agents	agents= ['player_1', 'player_2']
Agents	2
Action Shape	(1,)
Action Values	Discrete(18)
Observation Shape	(35,)
Observation Values	[-124,432]

Action Space

Value	Meaning	Value	Meaning	Value	Meaning
0	NOOP	1	FIRE	2	UP
3	RIGHT	4	LEFT	5	DOWN
6	UPRIGHT	7	UPLEFT	8	DOWNRIGHT
9	DOWNLEFT	10	UPFIRE	11	RIGHTFIRE
12	LEFTFIRE	13	DOWNFIRE	14	UPRIGHTFIRE
15	UPLEFTFIRE	16	DOWNRIGHTFIRE	17	DOWNLEFTFIRE

Observation Space

Index	Description	min	max
0	X position of player	32	400
1	Y position of player	108	244
2	Y Velocity of player	-15	16
3	Diving direction of player	-1	1
4	Player's remaining duration of lying down	-2	3
5	Player's frame number	0	4
6	Player's delay_before_next_frame	0	4
7	Whether player's power hit key was down previously	0	1
8	State of player (normal)	0	1
9	State of player (jumping)	0	1
10	State of player (jumping and power hitting)	0	1
11	State of player (diving)	0	1
12	State of player (lying down after diving)	0	1
13	X position of opponent player	32	400
14	Y position of opponent player	108	244
15	Y Velocity of opponent player	-15	16
16	Diving direction of opponent player	-1	1
17	Opponent player's remaining duration of lying down	-2	3
18	Opponent player's frame number	0	4
19	Opponent player's delay_before_next_frame	0	4
20	Whether opponent player's power hit key was down previously	0	1
21	State of opponent player (normal)	0	1
22	State of opponent player (jumping)	0	1
23	State of opponent player (jumping and power hitting)	0	1
24	State of opponent player (diving)	0	1
25	State of opponent player (lying down after diving)	0	1
26	X position of ball	20	432
27	Y position of ball	0	252
28	Previous X position of ball	0	432
29	Previous Y position of ball	0	252
30	Previous previous X position of ball	0	432
31	Previous previous Y position of ball	0	252
32	X Velocity of ball	-20	20
33	Y Velocity of ball	-124	124
34	If the ball is in POWER HIT status	0	1

• Since I do not know the exact minimum and maximum values of the ball's y velocity, I used the minimum and maximum values I observed.
• Previous X position of ball and Previous previous X position of ball have a low value of 0 because they are initialized to 0 at the start of the round.

Range of x position

• player1 : [32, 184]
• player2 : [248, 400]

Arguments

pikazoo_v0.env(
    winning_score=15,
    is_player1_computer=False,
    is_player2_computer=False,
)

• winning_score : The number of points needed to win a game.
• is_player1_computer : If this argument is True, player1 (left) will behave as the original game's rull-based AI, and its inputs will be ignored.
• is_player2_computer : If this argument is True, player2 (right) will behave as the original game's rull-based AI, and its inputs will be ignored.

Wrappers

SimplifyAction

Represent actions in relative directions instead of absolute directions, exclude actions that are not meaningful in gameplay, and reduce the number of valid actions from 18 to 13.

Value	Meaning	Value	Meaning	Value	Meaning
0	NOOP	1	FIRE	2	UP
3	FRONT	4	BACK	5	UPFRONT
6	UPBACK	7	UPFIRE	8	FRONTFIRE
9	BACKFIRE	10	DOWNFIRE	11	UPFRONTFIRE
12	DOWNFRONTFIRE

Relative Direction	Absolute Direction
FRONT	player_1 : RIGHT player_2 : LEFT
BACK	player_1 : LEFT player_2 : RIGHT

RewardByBallPosition

[20, x_line) [x_line, 432]
          x_line
        ┌───┼───┬→
        │ 0 │ 2 │ [0, y_line]
        ├───┼───┼─ y_line 
        │ 1 │ 3 │ (y_line, 252]
        ├───┴───┘
        ↓

• Argument
  • additional_reward : When the ball is in zone n, player_1 gets the value at index n, and player_2 gets the reward at index n+4.
  • x_line : The line separating the x-coordinates
  • y_line : The line separating the y-coordinates