[tab] data/jasmine_data/ViZDoomPPO/train_ppo_parallel.py (python)
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# FORK OF LEANDRO KIELIGER'S DOOM PPO TUTORIAL: https://lkieliger.medium.com/deep-reinforcement-learning-in-practice-by-playing-doom-part-1-getting-started-618c99075c77                                                                                                       

# SCRIPT TO TRAIN A PPO AGENT ON THE ViZDOOM DEATHMATCH ENVIRONMENT. 

import numpy as np
import vizdoom
from common import envs
from common.models import CustomCNN
from stable_baselines3.common.vec_env import VecTransposeImage, SubprocVecEnv
import random
import string
from vizdoom.vizdoom import GameVariable
from collections import deque
import torch
import multiprocessing

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
# device=torch.device("mps")
print(f"Using device: {device}")

# Rewards
# 1 per kill
reward_factor_frag = 1.0
reward_factor_damage = 0.01

# Player can move at ~16.66 units per tick
reward_factor_distance = 5e-4
penalty_factor_distance = -2.5e-3
reward_threshold_distance = 3.0

# Pistol clips have 10 bullets
reward_factor_ammo_increment = 0.02
reward_factor_ammo_decrement = -0.01

# Player starts at 100 health
reward_factor_health_increment = 0.02
reward_factor_health_decrement = -0.01
reward_factor_armor_increment = 0.01


# List of game variables storing ammunition information. Used for keeping track of ammunition-related rewards.
AMMO_VARIABLES = [
    GameVariable.AMMO0,
    GameVariable.AMMO1,
    GameVariable.AMMO2,
    GameVariable.AMMO3,
    GameVariable.AMMO4,
    GameVariable.AMMO5,
    GameVariable.AMMO6,
    GameVariable.AMMO7,
    GameVariable.AMMO8,
    GameVariable.AMMO9,
]

# List of game variables storing weapon information. Used for keeping track of ammunition-related rewards.
WEAPON_VARIABLES = [
    GameVariable.WEAPON0,
    GameVariable.WEAPON1,
    GameVariable.WEAPON2,
    GameVariable.WEAPON3,
    GameVariable.WEAPON4,
    GameVariable.WEAPON5,
    GameVariable.WEAPON6,
    GameVariable.WEAPON7,
    GameVariable.WEAPON8,
    GameVariable.WEAPON9,
]


class DoomWithBotsShaped(envs.DoomWithBots):
    """An environment wrapper for a Doom deathmatch game with bots.

    Rewards are shaped according to the multipliers defined in the notebook.
    """

    def __init__(self, game, frame_processor, frame_skip, n_bots, shaping):
        super().__init__(game, frame_processor, frame_skip, n_bots)

        # Give a random two-letter name to the agent for identifying instances in parallel learning.
        self.name = "".join(random.choices(string.ascii_uppercase + string.digits, k=2))
        self.shaping = shaping

        # Internal states
        self.last_health = 100
        self.last_x, self.last_y = self._get_player_pos()
        self.ammo_state = self._get_ammo_state()
        self.weapon_state = self._get_weapon_state()
        self.total_rew = self.last_damage_dealt = self.deaths = self.last_frags = (
            self.last_armor
        ) = 0

        # Store individual reward contributions for logging purposes
        self.rewards_stats = {
            "frag": 0,
            "damage": 0,
            "ammo": 0,
            "health": 0,
            "armor": 0,
            "distance": 0,
        }

    def step(self, action, array=False):
        # Perform the action as usual
        state, reward, done, info = super().step(action)

        self._log_reward_stat("frag", reward)

        # Adjust the reward based on the shaping table
        if self.shaping:
            shaped_reward = reward + self.shape_rewards()
        else:
            shaped_reward = reward

        self.total_rew += shaped_reward

        return state, shaped_reward, done, info

    def reset(self):
        self._print_state()

        state = super().reset()

        self.last_health = 100
        self.last_x, self.last_y = self._get_player_pos()
        self.last_armor = self.last_frags = self.total_rew = self.deaths = 0

        # Damage count  is not cleared when starting a new episode: https://github.com/mwydmuch/ViZDoom/issues/399
        # self.last_damage_dealt = 0

        # Reset reward stats
        for k in self.rewards_stats.keys():
            self.rewards_stats[k] = 0

        return state

    def seed(self, seed=None):
        if seed is not None:
            random.seed(seed)
            np.random.seed(seed)
        return [seed]

    def shape_rewards(self):
        reward_contributions = [
            self._compute_damage_reward(),
            self._compute_ammo_reward(),
            self._compute_health_reward(),
            self._compute_armor_reward(),
            self._compute_distance_reward(*self._get_player_pos()),
        ]

        return sum(reward_contributions)

    def _respawn_if_dead(self):
        if not self.game.is_episode_finished():
            # Check if player is dead
            if self.game.is_player_dead():
                self.deaths += 1
                self._reset_player()

    def _compute_distance_reward(self, x, y):
        """Computes a reward/penalty based on the distance travelled since last update."""
        dx = self.last_x - x
        dy = self.last_y - y

        distance = np.sqrt(dx**2 + dy**2)

        if distance - reward_threshold_distance > 0:
            reward = reward_factor_distance
        else:
            reward = -reward_factor_distance

        self.last_x = x
        self.last_y = y
        self._log_reward_stat("distance", reward)

        return reward

    def _compute_damage_reward(self):
        """Computes a reward based on total damage inflicted to enemies since last update."""
        damage_dealt = self.game.get_game_variable(GameVariable.DAMAGECOUNT)
        reward = reward_factor_damage * (damage_dealt - self.last_damage_dealt)

        self.last_damage_dealt = damage_dealt
        self._log_reward_stat("damage", reward)

        return reward

    def _compute_health_reward(self):
        """Computes a reward/penalty based on total health change since last update."""
        # When the player is dead, the health game variable can be -999900
        health = max(self.game.get_game_variable(GameVariable.HEALTH), 0)

        health_reward = reward_factor_health_increment * max(
            0, health - self.last_health
        )
        health_penalty = reward_factor_health_decrement * min(
            0, health - self.last_health
        )
        reward = health_reward - health_penalty

        self.last_health = health
        self._log_reward_stat("health", reward)

        return reward

    def _compute_armor_reward(self):
        """Computes a reward/penalty based on total armor change since last update."""
        armor = self.game.get_game_variable(GameVariable.ARMOR)
        reward = reward_factor_armor_increment * max(0, armor - self.last_armor)

        self.last_armor = armor
        self._log_reward_stat("armor", reward)

        return reward

    def _compute_ammo_reward(self):
        """Computes a reward/penalty based on total ammunition change since last update."""
        self.weapon_state = self._get_weapon_state()

        new_ammo_state = self._get_ammo_state()
        ammo_diffs = (new_ammo_state - self.ammo_state) * self.weapon_state
        ammo_reward = reward_factor_ammo_increment * max(0, np.sum(ammo_diffs))
        ammo_penalty = reward_factor_ammo_decrement * min(0, np.sum(ammo_diffs))
        reward = ammo_reward - ammo_penalty

        self.ammo_state = new_ammo_state
        self._log_reward_stat("ammo", reward)

        return reward

    def _get_player_pos(self):
        """Returns the player X- and Y- coordinates."""
        return self.game.get_game_variable(
            GameVariable.POSITION_X
        ), self.game.get_game_variable(GameVariable.POSITION_Y)

    def _get_ammo_state(self):
        """Returns the total available ammunition per weapon slot."""
        ammo_state = np.zeros(10)

        for i in range(10):
            ammo_state[i] = self.game.get_game_variable(AMMO_VARIABLES[i])

        return ammo_state

    def _get_weapon_state(self):
        """Returns which weapon slots can be used. Available weapons are encoded as ones."""
        weapon_state = np.zeros(10)

        for i in range(10):
            weapon_state[i] = self.game.get_game_variable(WEAPON_VARIABLES[i])

        return weapon_state

    def _log_reward_stat(self, kind: str, reward: float):
        self.rewards_stats[kind] += reward

    def _reset_player(self):
        self.last_health = 100
        self.last_armor = 0
        self.game.respawn_player()
        self.last_x, self.last_y = self._get_player_pos()
        self.ammo_state = self._get_ammo_state()

    def _print_state(self):
        super()._print_state()


REWARD_THRESHOLDS = [5, 10, 15, 20, 25, 25]

# Curriculum based learning
class DoomWithBotsCurriculum(DoomWithBotsShaped):
    def __init__(
        self,
        game,
        frame_processor,
        frame_skip,
        n_bots,
        shaping,
        initial_level=0,
        max_level=5,
        rolling_mean_length=10,
    ):
        super().__init__(game, frame_processor, frame_skip, n_bots, shaping)

        # Initialize ACS script difficulty level
        game.send_game_command("pukename change_difficulty 0")

        # Internal state
        self.level = initial_level
        self.max_level = max_level
        self.rolling_mean_length = rolling_mean_length
        self.last_rewards = deque(maxlen=rolling_mean_length)

    def step(self, action, array=False):
        # Perform action step as usual
        state, reward, done, infos = super().step(action, array)

        # After an episode, check whether difficulty should be increased.
        if done:
            self.last_rewards.append(self.total_rew)
            run_mean = np.mean(self.last_rewards)
            print(
                "Avg. last 10 runs of {}: {:.2f}. Current difficulty level: {}".format(
                    self.name, run_mean, self.level
                )
            )
            if (
                run_mean > REWARD_THRESHOLDS[self.level]
                and len(self.last_rewards) >= self.rolling_mean_length
            ):
                self._change_difficulty()

        return state, reward, done, infos

    def reset(self):
        state = super().reset()
        self.game.send_game_command(f"pukename change_difficulty {self.level}")

        return state

    def _change_difficulty(self):
        """Adjusts the difficulty by setting the difficulty level in the ACS script."""
        if self.level < self.max_level:
            self.level += 1
            print(f"Changing difficulty for {self.name} to {self.level}")
            self.game.send_game_command(f"pukename change_difficulty {self.level}")
            self.last_rewards = deque(maxlen=self.rolling_mean_length)
        else:
            print(f"{self.name} already at max level!")


def game_instance(scenario):
    """Creates a Doom game instance."""
    game = vizdoom.DoomGame()
    game.load_config(f"scenarios/{scenario}.cfg")
    game.add_game_args(envs.DOOM_ENV_WITH_BOTS_ARGS)
    game.set_window_visible(False)
    game.init()

    return game


def env_with_bots_shaped(scenario, **kwargs) -> envs.DoomEnv:
    """Wraps a Doom game instance in an environment with shaped rewards."""
    game = game_instance(scenario)
    return DoomWithBotsShaped(game, **kwargs)


def vec_env_with_bots_shaped(n_envs=1, **kwargs) -> VecTransposeImage:
    """Wraps Doom game instances in a vectorized environment with shaped rewards using true parallelism."""
    return VecTransposeImage(
        SubprocVecEnv([lambda: env_with_bots_shaped(**kwargs) for _ in range(n_envs)])
    )


def env_with_bots_curriculum(scenario, **kwargs) -> envs.DoomEnv:
    """Wraps a Doom game instance in an environment with shaped rewards and curriculum."""
    game = game_instance(scenario)
    return DoomWithBotsCurriculum(game, **kwargs)


def vec_env_with_bots_curriculum(n_envs=1, **kwargs) -> VecTransposeImage:
    """Wraps a Doom game instance in a vectorized environment with shaped rewards and curriculum."""
    return VecTransposeImage(
        SubprocVecEnv([lambda: env_with_bots_curriculum(**kwargs) for _ in range(n_envs)])
    )


if __name__ == "__main__":
    scenario = "deathmatch_simple"

    # Agent parameters.
    agent_args = {
        "n_steps": 4096,
        "learning_rate": 1e-4,
        "batch_size": 64,
        "policy_kwargs": {"features_extractor_class": CustomCNN},
        "device": device,
    }

    # Environment parameters.
    env_args = {
        "scenario": scenario,
        "frame_skip": 4,
        "frame_processor": envs.default_frame_processor,
        "n_bots": 6,
        "shaping": True,
        "initial_level": 1,
        "max_level": 5,
    }

    # In the evaluation environment we measure frags only.
    eval_env_args = dict(env_args)
    eval_env_args["shaping"] = False

    n_envs = multiprocessing.cpu_count() - 1
    # Create environments with bots and shaping.
    env = vec_env_with_bots_curriculum(
        n_envs, **env_args
    )  # You can increase the number of parallel environments
    eval_env = vec_env_with_bots_curriculum(n_envs, **eval_env_args)

    agent = envs.solve_env(
        env,
        eval_env,
        scenario,
        agent_args,
        resume=False,
    )
    envs.save_model(agent, "agent_test")