File size: 4,728 Bytes
97b6013 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 |
# Copyright 2018 The TensorFlow Authors All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ==============================================================================
"""Wrapper for creating the ant environment in gym_mujoco."""
import math
import numpy as np
import mujoco_py
from gym import utils
from gym.envs.mujoco import mujoco_env
def q_inv(a):
return [a[0], -a[1], -a[2], -a[3]]
def q_mult(a, b): # multiply two quaternion
w = a[0] * b[0] - a[1] * b[1] - a[2] * b[2] - a[3] * b[3]
i = a[0] * b[1] + a[1] * b[0] + a[2] * b[3] - a[3] * b[2]
j = a[0] * b[2] - a[1] * b[3] + a[2] * b[0] + a[3] * b[1]
k = a[0] * b[3] + a[1] * b[2] - a[2] * b[1] + a[3] * b[0]
return [w, i, j, k]
class AntEnv(mujoco_env.MujocoEnv, utils.EzPickle):
FILE = "ant.xml"
ORI_IND = 3
def __init__(self, file_path=None, expose_all_qpos=True,
expose_body_coms=None, expose_body_comvels=None):
self._expose_all_qpos = expose_all_qpos
self._expose_body_coms = expose_body_coms
self._expose_body_comvels = expose_body_comvels
self._body_com_indices = {}
self._body_comvel_indices = {}
mujoco_env.MujocoEnv.__init__(self, file_path, 5)
utils.EzPickle.__init__(self)
@property
def physics(self):
# check mujoco version is greater than version 1.50 to call correct physics
# model containing PyMjData object for getting and setting position/velocity
# check https://github.com/openai/mujoco-py/issues/80 for updates to api
if mujoco_py.get_version() >= '1.50':
return self.sim
else:
return self.model
def _step(self, a):
return self.step(a)
def step(self, a):
xposbefore = self.get_body_com("torso")[0]
self.do_simulation(a, self.frame_skip)
xposafter = self.get_body_com("torso")[0]
forward_reward = (xposafter - xposbefore) / self.dt
ctrl_cost = .5 * np.square(a).sum()
survive_reward = 1.0
reward = forward_reward - ctrl_cost + survive_reward
state = self.state_vector()
done = False
ob = self._get_obs()
return ob, reward, done, dict(
reward_forward=forward_reward,
reward_ctrl=-ctrl_cost,
reward_survive=survive_reward)
def _get_obs(self):
# No cfrc observation
if self._expose_all_qpos:
obs = np.concatenate([
self.physics.data.qpos.flat[:15], # Ensures only ant obs.
self.physics.data.qvel.flat[:14],
])
else:
obs = np.concatenate([
self.physics.data.qpos.flat[2:15],
self.physics.data.qvel.flat[:14],
])
if self._expose_body_coms is not None:
for name in self._expose_body_coms:
com = self.get_body_com(name)
if name not in self._body_com_indices:
indices = range(len(obs), len(obs) + len(com))
self._body_com_indices[name] = indices
obs = np.concatenate([obs, com])
if self._expose_body_comvels is not None:
for name in self._expose_body_comvels:
comvel = self.get_body_comvel(name)
if name not in self._body_comvel_indices:
indices = range(len(obs), len(obs) + len(comvel))
self._body_comvel_indices[name] = indices
obs = np.concatenate([obs, comvel])
return obs
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
# Set everything other than ant to original position and 0 velocity.
qpos[15:] = self.init_qpos[15:]
qvel[14:] = 0.
self.set_state(qpos, qvel)
return self._get_obs()
def viewer_setup(self):
self.viewer.cam.distance = self.model.stat.extent * 0.5
def get_ori(self):
ori = [0, 1, 0, 0]
rot = self.physics.data.qpos[self.__class__.ORI_IND:self.__class__.ORI_IND + 4] # take the quaternion
ori = q_mult(q_mult(rot, ori), q_inv(rot))[1:3] # project onto x-y plane
ori = math.atan2(ori[1], ori[0])
return ori
def set_xy(self, xy):
qpos = np.copy(self.physics.data.qpos)
qpos[0] = xy[0]
qpos[1] = xy[1]
qvel = self.physics.data.qvel
self.set_state(qpos, qvel)
def get_xy(self):
return self.physics.data.qpos[:2]
|