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Mujoco_WASM/mjx/mujoco/mjx/_src/support_test.py
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Baruch Tabanpour c6b1293e58 Add contact force support function. #1555
PiperOrigin-RevId: 632591177
Change-Id: I15aa00686d9f885330506d2d63443c700cc029f6
2024-05-10 13:41:45 -07:00

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7.3 KiB
Python

# Copyright 2023 DeepMind Technologies Limited
#
# 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.
# ==============================================================================
"""Tests for support."""
from absl.testing import absltest
from absl.testing import parameterized
import jax
from jax import numpy as jp
import mujoco
from mujoco import mjx
from mujoco.mjx._src import support
from mujoco.mjx._src import test_util
import numpy as np
class SupportTest(parameterized.TestCase):
def test_mul_m(self):
m = test_util.load_test_file('pendula.xml')
# first test sparse
m.opt.jacobian = mujoco.mjtJacobian.mjJAC_SPARSE
d = mujoco.MjData(m)
# give the system a little kick to ensure we have non-identity rotations
d.qvel = np.random.random(m.nv)
mujoco.mj_step(m, d, 10) # let dynamics get state significantly non-zero
mujoco.mj_forward(m, d)
mx = mjx.put_model(m)
dx = mjx.put_data(m, d)
vec = np.random.random(m.nv)
mjx_vec = jax.jit(mjx.mul_m)(mx, dx, jp.array(vec))
mj_vec = np.zeros(m.nv)
mujoco.mj_mulM(m, d, mj_vec, vec)
np.testing.assert_allclose(mjx_vec, mj_vec, atol=5e-5, rtol=5e-5)
# also check dense
m.opt.jacobian = mujoco.mjtJacobian.mjJAC_DENSE
mujoco.mj_forward(m, d)
mx = mjx.put_model(m)
dx = mjx.put_data(m, d)
mjx_vec = jax.jit(mjx.mul_m)(mx, dx, jp.array(vec))
np.testing.assert_allclose(mjx_vec, mj_vec, atol=5e-5, rtol=5e-5)
def test_full_m(self):
m = test_util.load_test_file('pendula.xml')
# for the model to be sparse to exercise MJX full_M
m.opt.jacobian = mujoco.mjtJacobian.mjJAC_SPARSE
d = mujoco.MjData(m)
# give the system a little kick to ensure we have non-identity rotations
d.qvel = np.random.random(m.nv)
mujoco.mj_step(m, d, 10) # let dynamics get state significantly non-zero
mx = mjx.put_model(m)
dx = mjx.put_data(m, d)
mjx_full_m = jax.jit(support.full_m)(mx, dx)
mj_full_m = np.zeros((m.nv, m.nv), dtype=np.float64)
mujoco.mj_fullM(m, mj_full_m, d.qM)
np.testing.assert_allclose(mjx_full_m, mj_full_m, atol=5e-5, rtol=5e-5)
@parameterized.parameters('constraints.xml', 'pendula.xml')
def test_jac(self, fname):
np.random.seed(0)
m = test_util.load_test_file(fname)
d = mujoco.MjData(m)
mujoco.mj_step(m, d)
mx = mjx.put_model(m)
dx = mjx.put_data(m, d)
point = np.random.randn(3)
body = np.random.choice(m.nbody)
jacp, jacr = jax.jit(support.jac)(mx, dx, point, body)
jacp_expected, jacr_expected = np.zeros((3, m.nv)), np.zeros((3, m.nv))
mujoco.mj_jac(m, d, jacp_expected, jacr_expected, point, body)
np.testing.assert_almost_equal(jacp, jacp_expected.T, 6)
np.testing.assert_almost_equal(jacr, jacr_expected.T, 6)
def test_xfrc_accumulate(self):
"""Tests that xfrc_accumulate ouput matches mj_xfrcAccumulate."""
np.random.seed(0)
m = test_util.load_test_file('pendula.xml')
d = mujoco.MjData(m)
mujoco.mj_step(m, d)
mx = mjx.put_model(m)
dx = mjx.put_data(m, d)
self.assertFalse((dx.xipos == 0.0).all())
xfrc = np.random.rand(*dx.xfrc_applied.shape)
d.xfrc_applied[:] = xfrc
dx = dx.replace(xfrc_applied=jp.array(xfrc))
qfrc = jax.jit(support.xfrc_accumulate)(mx, dx)
qfrc_expected = np.zeros(m.nv)
for i in range(1, m.nbody):
mujoco.mj_applyFT(
m,
d,
d.xfrc_applied[i, :3],
d.xfrc_applied[i, 3:],
d.xipos[i],
i,
qfrc_expected,
)
np.testing.assert_almost_equal(qfrc, qfrc_expected, 6)
def test_custom(self):
xml = """
<mujoco model="right_shadow_hand">
<custom>
<numeric data="15" name="max_contact_points"/>
<numeric data="42" name="max_geom_pairs"/>
</custom>
</mujoco>
"""
m = mujoco.MjModel.from_xml_string(xml)
def _get_numeric(m, name):
id_ = support.name2id(m, mujoco.mjtObj.mjOBJ_NUMERIC, name)
return int(m.numeric_data[id_]) if id_ >= 0 else -1
self.assertEqual(_get_numeric(m, 'something'), -1)
self.assertEqual(_get_numeric(m, 'max_contact_points'), 15)
self.assertEqual(_get_numeric(m, 'max_geom_pairs'), 42)
mx = mjx.put_model(m)
self.assertEqual(_get_numeric(mx, 'something'), -1)
self.assertEqual(_get_numeric(mx, 'max_contact_points'), 15)
self.assertEqual(_get_numeric(mx, 'max_geom_pairs'), 42)
def test_names_and_ids(self):
m = test_util.load_test_file('pendula.xml')
mx = mjx.put_model(m)
nums = {
mujoco.mjtObj.mjOBJ_JOINT: m.njnt,
mujoco.mjtObj.mjOBJ_GEOM: m.ngeom,
mujoco.mjtObj.mjOBJ_BODY: m.nbody,
}
for obj in nums:
names = [mujoco.mj_id2name(m, obj.value, i) for i in range(nums[obj])]
for i, n in enumerate(names):
self.assertEqual(support.id2name(mx, obj, i), n)
i = i if n is not None else -1
self.assertEqual(support.name2id(mx, obj, n), i)
_CONTACTS = """
<mujoco>
<worldbody>
<body pos="0 0 0.55" euler="1 0 0">
<joint axis="1 0 0" type="free"/>
<geom fromto="-0.4 0 0 0.4 0 0" size="0.05" type="capsule" condim="6"/>
</body>
<body pos="0 0 0.5" euler="0 1 0">
<joint axis="1 0 0" type="free"/>
<geom fromto="-0.4 0 0 0.4 0 0" size="0.05" type="capsule" condim="3"/>
</body>
<body pos="0 0 0.445" euler="0 90 0">
<joint axis="1 0 0" type="free"/>
<geom fromto="-0.4 0 0 0.4 0 0" size="0.05" type="capsule" condim="1"/>
</body>
</worldbody>
</mujoco>
"""
def test_contact_force(self):
m = mujoco.MjModel.from_xml_string(self._CONTACTS)
d = mujoco.MjData(m)
mujoco.mj_step(m, d)
assert (
np.unique(d.contact.geom).shape[0] == 3
), 'This test assumes all capsule are in contact.'
mx = mjx.put_model(m)
dx = mjx.put_data(m, d)
mujoco.mj_step(m, d)
dx = mjx.step(mx, dx)
# map MJX contacts to MJ ones
def _find(g):
val = (g == dx.contact.geom).sum(axis=1)
return np.where(val == 2)[0][0]
contact_id_map = {i: _find(d.contact.geom[i]) for i in range(d.ncon)}
for i in range(d.ncon):
result = np.zeros(6, dtype=float)
mujoco.mj_contactForce(m, d, i, result)
j = contact_id_map[i]
force = jax.jit(support.contact_force, static_argnums=(2,))(mx, dx, j)
np.testing.assert_allclose(result, force, rtol=1e-5, atol=2)
# test world conversion
force = jax.jit(
support.contact_force,
static_argnums=(
2,
3,
),
)(mx, dx, j, True)
# back to contact frame
force = force.at[:3].set(dx.contact.frame[j] @ force[:3])
force = force.at[3:].set(dx.contact.frame[j] @ force[3:])
np.testing.assert_allclose(result, force, rtol=1e-5, atol=2)
if __name__ == '__main__':
absltest.main()