ray/rllib/examples/env/ant_rand_goal.py

75 lines
2.4 KiB
Python

from gym.envs.mujoco.mujoco_env import MujocoEnv
from gym.utils import EzPickle
import numpy as np
from ray.rllib.env.apis.task_settable_env import TaskSettableEnv
class AntRandGoalEnv(EzPickle, MujocoEnv, TaskSettableEnv):
"""Ant Environment that randomizes goals as tasks
Goals are randomly sampled 2D positions
"""
def __init__(self):
self.set_task(self.sample_tasks(1)[0])
MujocoEnv.__init__(self, "ant.xml", 5)
EzPickle.__init__(self)
def sample_tasks(self, n_tasks):
# Samples a goal position (2x1 position ector)
a = np.random.random(n_tasks) * 2 * np.pi
r = 3 * np.random.random(n_tasks)**0.5
return np.stack((r * np.cos(a), r * np.sin(a)), axis=-1)
def set_task(self, task):
"""
Args:
task: task of the meta-learning environment
"""
self.goal_pos = task
def get_task(self):
"""
Returns:
task: task of the meta-learning environment
"""
return self.goal_pos
def step(self, a):
self.do_simulation(a, self.frame_skip)
xposafter = self.get_body_com("torso")
goal_reward = -np.sum(np.abs(
xposafter[:2] - self.goal_pos)) # make it happy, not suicidal
ctrl_cost = .1 * np.square(a).sum()
contact_cost = 0.5 * 1e-3 * np.sum(
np.square(np.clip(self.sim.data.cfrc_ext, -1, 1)))
# survive_reward = 1.0
survive_reward = 0.0
reward = goal_reward - ctrl_cost - contact_cost + survive_reward
# notdone = np.isfinite(state).all() and 1.0 >= state[2] >= 0.
# done = not notdone
done = False
ob = self._get_obs()
return ob, reward, done, dict(
reward_forward=goal_reward,
reward_ctrl=-ctrl_cost,
reward_contact=-contact_cost,
reward_survive=survive_reward)
def _get_obs(self):
return np.concatenate([
self.sim.data.qpos.flat,
self.sim.data.qvel.flat,
np.clip(self.sim.data.cfrc_ext, -1, 1).flat,
])
def reset_model(self):
qpos = self.init_qpos + self.np_random.uniform(
size=self.model.nq, low=-.1, high=.1)
qvel = self.init_qvel + self.np_random.randn(self.model.nv) * .1
self.set_state(qpos, qvel)
return self._get_obs()
def viewer_setup(self):
self.viewer.cam.distance = self.model.stat.extent * 0.5