def _make_model(n_poles):
"""Generates an xml string defining a cart with `n_poles` bodies."""
xml_string = common.read_model('cartpole.xml')
if n_poles == 1:
return xml_string
mjcf = etree.fromstring(xml_string)
parent = mjcf.find('./worldbody/body/body') # Find first pole.
# Make chain of poles.
for pole_index in range(2, n_poles + 1):
child = etree.Element('body',
name='pole_{}'.format(pole_index),
pos='0 0 1',
childclass='pole')
etree.SubElement(child, 'joint', name='hinge_{}'.format(pole_index))
etree.SubElement(child, 'geom', name='pole_{}'.format(pole_index))
parent.append(child)
parent = child
# Move plane down.
floor = mjcf.find('./worldbody/geom')
floor.set('pos', '0 0 {}'.format(1 - n_poles - .05))
# Move cameras back.
cameras = mjcf.findall('./worldbody/camera')
cameras[0].set('pos', '0 {} 1'.format(-1 - 2 * n_poles))
cameras[1].set('pos', '0 {} 2'.format(-2 * n_poles))
return etree.tostring(mjcf, pretty_print=True)
def make_model(n_boxes):
"""Returns a tuple containing the model XML string and a dict of assets."""
xml_string = common.read_model('stacker.xml')
parser = etree.XMLParser(remove_blank_text=True)
mjcf = etree.XML(xml_string, parser)
# Remove unused boxes
for b in range(n_boxes, 4):
box = xml_tools.find_element(mjcf, 'body', 'box' + str(b))
box.getparent().remove(box)
return etree.tostring(mjcf, pretty_print=True), common.ASSETS
def _make_model(n_bodies):
"""Generates an xml string defining a swimmer with `n_bodies` bodies."""
if n_bodies < 3:
raise ValueError(
'At least 3 bodies required. Received {}'.format(n_bodies))
mjcf = etree.fromstring(common.read_model('swimmer.xml'))
head_body = mjcf.find('./worldbody/body')
actuator = etree.SubElement(mjcf, 'actuator')
sensor = etree.SubElement(mjcf, 'sensor')
parent = head_body
for body_index in range(n_bodies - 1):
site_name = 'site_{}'.format(body_index)
child = _make_body(body_index=body_index)
child.append(etree.Element('site', name=site_name))
joint_name = 'joint_{}'.format(body_index)
joint_limit = 360.0 / n_bodies
joint_range = '{} {}'.format(-joint_limit, joint_limit)
child.append(
etree.Element('joint', {
'name': joint_name,
'range': joint_range
}))
motor_name = 'motor_{}'.format(body_index)
actuator.append(
etree.Element('motor', name=motor_name, joint=joint_name))
velocimeter_name = 'velocimeter_{}'.format(body_index)
sensor.append(
etree.Element('velocimeter', name=velocimeter_name,
site=site_name))
gyro_name = 'gyro_{}'.format(body_index)
sensor.append(etree.Element('gyro', name=gyro_name, site=site_name))
parent.append(child)
parent = child
# Move tracking cameras further away from the swimmer according to its length.
cameras = mjcf.findall('./worldbody/body/camera')
scale = n_bodies / 6.0
for cam in cameras:
if cam.get('mode') == 'trackcom':
old_pos = cam.get('pos').split(' ')
new_pos = ' '.join([str(float(dim) * scale) for dim in old_pos])
cam.set('pos', new_pos)
return etree.tostring(mjcf, pretty_print=True)
def make_model(use_peg, insert):
"""Returns a tuple containing the model XML string and a dict of assets."""
xml_string = common.read_model('manipulator.xml')
parser = etree.XMLParser(remove_blank_text=True)
mjcf = etree.XML(xml_string, parser)
# Select the desired prop.
if use_peg:
required_props = ['peg', 'target_peg']
if insert:
required_props += ['slot']
else:
required_props = ['ball', 'target_ball']
if insert:
required_props += ['cup']
# Remove unused props
for unused_prop in _ALL_PROPS.difference(required_props):
prop = xml_tools.find_element(mjcf, 'body', unused_prop)
prop.getparent().remove(prop)
return etree.tostring(mjcf, pretty_print=True), common.ASSETS
def get_model_and_assets():
"""Returns a tuple containing the model XML string and a dict of assets."""
return common.read_model('reacher.xml'), common.ASSETS