def __init__(self, bvh_filename):
with open(bvh_filename) as f:
mocap = Bvh(f.read())
MOCAP_TO_OSIM_HEIGHT = 0.94 / 17.6356
MOCAP_TO_OSIM_TRANSLATION = 1.27441 # the relative position of the left toes in the first frame of mocap data
self.nframes = mocap.nframes
self.frame_time = mocap.frame_time
self.joints = {}
self.joints['hip_l'] = np.array([
self.align_mocap_to_osim(eul_mocap, [0, 0, 21])
for eul_mocap in mocap.frames_joint_channels(
'LeftUpLeg', ['Xrotation', 'Yrotation', 'Zrotation'])
])
self.joints['hip_r'] = np.array([
self.align_mocap_to_osim(eul_mocap, [0, 0, -21])
for eul_mocap in mocap.frames_joint_channels(
'RightUpLeg', ['Xrotation', 'Yrotation', 'Zrotation'])
])
self.joints['knee_l'] = np.array([
self.align_mocap_to_osim(eul_mocap, [0, 0, 21])
for eul_mocap in mocap.frames_joint_channels(
'LeftLeg', ['Xrotation', 'Yrotation', 'Zrotation'])
])[:, :1]
self.joints['knee_r'] = np.array([
self.align_mocap_to_osim(eul_mocap, [0, 0, -21])
for eul_mocap in mocap.frames_joint_channels(
'RightLeg', ['Xrotation', 'Yrotation', 'Zrotation'])
])[:, :1]
self.joints['ankle_l'] = np.array([
self.align_mocap_to_osim(eul_mocap, [0, 0, 21])
for eul_mocap in mocap.frames_joint_channels(
'LeftFoot', ['Xrotation', 'Yrotation', 'Zrotation'])
])[:, :1]
self.joints['ground_pelvis'] = np.array([
mocap.frames_joint_channels('Pelvis', [
'Xrotation', 'Yrotation', 'Zrotation', 'Xposition',
'Yposition', 'Zposition'
])
]).squeeze()
# now make a few tweaks to the reference motion to zero out some joints
self.joints[
'ground_pelvis'][:, 3:] = self.joints['ground_pelvis'][:, 3:].dot(
matrix_from_euler(0, -90, 0)) * MOCAP_TO_OSIM_HEIGHT
self.joints['ground_pelvis'][:, 3] += MOCAP_TO_OSIM_TRANSLATION
self.joints['ground_pelvis'][:, :3] = self.joints[
'hip_l'][:, 1:] = self.joints['hip_r'][:, 1:] = 0
def test_frames_multi_channels(self):
with open('tests/test_mocapbank.bvh') as f:
mocap = Bvh(f.read())
rotations = mocap.frames_joint_channels('Head', ['Xrotation', 'Yrotation', 'Zrotation'])
self.assertEqual(len(rotations), mocap.nframes)
