Files
Gymnasium/gym/envs/mujoco/hopper.py
2016-04-27 08:00:58 -07:00

42 lines
1.5 KiB
Python

import numpy as np
from gym import utils
from gym.envs.mujoco import mujoco_env
class HopperEnv(mujoco_env.MujocoEnv, utils.EzPickle):
def __init__(self):
mujoco_env.MujocoEnv.__init__(self, 'hopper.xml', 4)
utils.EzPickle.__init__(self)
self.finalize()
def _step(self, a):
posbefore = self.model.data.qpos[0,0]
self.do_simulation(a, self.frame_skip)
posafter,height,ang = self.model.data.qpos[0:3,0]
alive_bonus = 1.0
reward = (posafter - posbefore) / self.dt
reward += alive_bonus
reward -= 1e-3 * np.square(a).sum()
s = self._state
done = not (np.isfinite(s).all() and (np.abs(s[2:]) < 100).all() and
(height > .7) and (abs(ang) < .2))
ob = self._get_obs()
return ob, reward, done, {}
def _get_obs(self):
return np.concatenate([
self.model.data.qpos.flat[1:],
np.clip(self.model.data.qvel.flat,-10,10)
])
def _reset(self):
self.model.data.qpos = self.init_qpos + np.random.rand(self.model.nq,1)*.01-.005
self.model.data.qvel = self.init_qvel + np.random.rand(self.model.nv,1)*.01-.005
self.reset_viewer_if_necessary()
return self._get_obs()
def viewer_setup(self):
self.viewer.cam.trackbodyid = 2
self.viewer.cam.distance = self.model.stat.extent * 0.75
self.viewer.cam.lookat[2] += .8
self.viewer.cam.elevation = -20