5.3 KiB
title
| title |
|---|
| Riverraid |
Riverraid
:width: 120px
:name: Riverraid
This environment is part of the Atari environments. Please read that page first for general information.
Description
You control a jet that flies over a river: you can move it sideways and fire missiles to destroy enemy objects. Each time an enemy object is destroyed you score points (i.e. rewards).You lose a jet when you run out of fuel: fly over a fuel depot when you begin to run low.You lose a jet even when it collides with the river bank or one of the enemy objects (except fuel depots).The game begins with a squadron of three jets in reserve and you're given an additional jet (up to 9) for each 10,000 points you score.
For a more detailed documentation, see the AtariAge page
Actions
Riverraid has the action space Discrete(18) with the table below lists the meaning of each action's meanings.
As Riverraid uses the full set of actions then specifying full_action_space=True will not modify the action space of the environment if passed to gymnasium.make.
| 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 |
Observations
Atari environment have two possible observation types, the observation space is listed below. See variants section for the type of observation used by each environment id.
obs_type="rgb" -> observation_space=Box(0, 255, (210, 160, 3), np.uint8)obs_type="ram" -> observation_space=Box(0, 255, (128,), np.uint8)
Additionally, obs_type="grayscale" cause the environment return a grayscale version of the rgb array for observations with the observation space being Box(0, 255, (210, 160), np.uint8)
Rewards
Score points are your only reward. You get score points each time you destroy an enemy object:
| Enemy Object | Score Points |
|---|---|
| Tanker | 30 |
| Helicopter | 60 |
| Fuel Depot | 80 |
| Jet | 100 |
| Bridge | 500 |
For a more detailed documentation, see the AtariAge page.
Variants
Riverraid has the following variants of the environment id which have the following differences in observation, the number of frame-skips and the repeat action probability.
| Env-id | obs_type= | frameskip= | repeat_action_probability= |
|---|---|---|---|
| Riverraid-v0 | "rgb" |
(2, 5) |
0.25 |
| Riverraid-ram-v0 | "ram" |
(2, 5) |
0.25 |
| Riverraid-ramDeterministic-v0 | "ram" |
4 |
0.25 |
| Riverraid-ramNoFrameskip-v0 | "ram" |
1 |
0.25 |
| RiverraidDeterministic-v0 | "rgb" |
4 |
0.25 |
| RiverraidNoFrameskip-v0 | "rgb" |
1 |
0.25 |
| Riverraid-v4 | "rgb" |
(2, 5) |
0.0 |
| Riverraid-ram-v4 | "ram" |
(2, 5) |
0.0 |
| Riverraid-ramDeterministic-v4 | "ram" |
4 |
0.0 |
| Riverraid-ramNoFrameskip-v4 | "ram" |
1 |
0.0 |
| RiverraidDeterministic-v4 | "rgb" |
4 |
0.0 |
| RiverraidNoFrameskip-v4 | "rgb" |
1 |
0.0 |
| ALE/Riverraid-v5 | "rgb" |
4 |
0.25 |
| ALE/Riverraid-ram-v5 | "ram" |
4 |
0.25 |
Difficulty and modes
It is possible to specify various flavors of the environment via the keyword arguments difficulty and mode.
A flavor is a combination of a game mode and a difficulty setting. The table below lists the possible difficulty and mode values
along with the default values.
| Available Modes | Default Mode | Available Difficulties | Default Difficulty |
|---|---|---|---|
[0] |
0 |
[0, 1] |
0 |
Version History
A thorough discussion of the intricate differences between the versions and configurations can be found in the general article on Atari environments.
- v5: Stickiness was added back and stochastic frameskipping was removed. The environments are now in the "ALE" namespace.
- v4: Stickiness of actions was removed
- v0: Initial versions release