"""
This code is modified from:
http://theorangeduck.com/page/deep-learning-framework-character-motion-synthesis-and-editing
by Daniel Holden et al
"""
import re
import numpy as np
from bvh.Quaternions import Quaternions
channelmap = {
'Xrotation' : 'x',
'Yrotation' : 'y',
'Zrotation' : 'z'
}
channelmap_inv = {
'x': 'Xrotation',
'y': 'Yrotation',
'z': 'Zrotation',
}
ordermap = {
'x': 0,
'y': 1,
'z': 2,
}
class Animation:
def __init__(self, rotations, positions, orients, offsets, parents, names, frametime):
self.rotations = rotations
self.positions = positions
self.orients = orients
self.offsets = offsets
self.parent = parents
self.names = names
self.frametime = frametime
@property
def shape(self):
return self.rotations.shape
def load(filename, start=None, end=None, order=None, world=False, need_quater=False) -> Animation:
"""
Reads a BVH file and constructs an animation
Parameters
----------
filename: str
File to be opened
start : int
Optional Starting Frame
end : int
Optional Ending Frame
order : str
Optional Specifier for joint order.
Given as string E.G 'xyz', 'zxy'
world : bool
If set to true euler angles are applied
together in world space rather than local
space
Returns
-------
(animation, joint_names, frametime)
Tuple of loaded animation and joint names
"""
f = open(filename, "r")
i = 0
active = -1
end_site = False
names = []
orients = Quaternions.id(0)
offsets = np.array([]).reshape((0, 3))
parents = np.array([], dtype=int)
orders = []
for line in f:
if "HIERARCHY" in line: continue
if "MOTION" in line: continue
""" Modified line read to handle mixamo data """
# rmatch = re.match(r"ROOT (\w+)", line)
rmatch = re.match(r"ROOT (\w+:?\w+)", line)
if rmatch:
names.append(rmatch.group(1))
offsets = np.append(offsets, np.array([[0, 0, 0]]), axis=0)
orients.qs = np.append(orients.qs, np.array([[1, 0, 0, 0]]), axis=0)
parents = np.append(parents, active)
active = (len(parents) - 1)
continue
if "{" in line: continue
if "}" in line:
if end_site:
end_site = False
else:
active = parents[active]
continue
offmatch = re.match(r"\s*OFFSET\s+([\-\d\.e]+)\s+([\-\d\.e]+)\s+([\-\d\.e]+)", line)
if offmatch:
if not end_site:
offsets[active] = np.array([list(map(float, offmatch.groups()))])
continue
chanmatch = re.match(r"\s*CHANNELS\s+(\d+)", line)
if chanmatch:
channels = int(chanmatch.group(1))
channelis = 0 if channels == 3 else 3
channelie = 3 if channels == 3 else 6
parts = line.split()[2 + channelis:2 + channelie]
if any([p not in channelmap for p in parts]):
continue
order = "".join([channelmap[p] for p in parts])
orders.append(order)
continue
""" Modified line read to handle mixamo data """
# jmatch = re.match("\s*JOINT\s+(\w+)", line)
jmatch = re.match("\s*JOINT\s+(\w+:?\w+)", line)
if jmatch:
names.append(jmatch.group(1))
offsets = np.append(offsets, np.array([[0, 0, 0]]), axis=0)
orients.qs = np.append(orients.qs, np.array([[1, 0, 0, 0]]), axis=0)
parents = np.append(parents, active)
active = (len(parents) - 1)
continue
if "End Site" in line:
end_site = True
continue
fmatch = re.match("\s*Frames:\s+(\d+)", line)
if fmatch:
if start and end:
fnum = (end - start) - 1
else:
fnum = int(fmatch.group(1))
jnum = len(parents)
positions = offsets[np.newaxis].repeat(fnum, axis=0)
rotations = np.zeros((fnum, len(orients), 3))
continue
fmatch = re.match("\s*Frame Time:\s+([\d\.]+)", line)
if fmatch:
frametime = float(fmatch.group(1))
continue
if (start and end) and (i < start or i >= end - 1):
i += 1
continue
# dmatch = line.strip().split(' ')
dmatch = line.strip().split()
if dmatch:
data_block = np.array(list(map(float, dmatch)))
N = len(parents)
fi = i - start if start else i
if channels == 3:
positions[fi, 0:1] = data_block[0:3]
rotations[fi, :] = data_block[3:].reshape(N, 3)
elif channels == 6:
data_block = data_block.reshape(N, 6)
positions[fi, :] = data_block[:, 0:3]
rotations[fi, :] = data_block[:, 3:6]
elif channels == 9:
positions[fi, 0] = data_block[0:3]
data_block = data_block[3:].reshape(N - 1, 9)
rotations[fi, 1:] = data_block[:, 3:6]
positions[fi, 1:] += data_block[:, 0:3] * data_block[:, 6:9]
else:
raise Exception("Too many channels! %i" % channels)
i += 1
f.close()
all_rotations = []
canonical_order = 'xyz'
for i, order in enumerate(orders):
rot = rotations[:, i:i + 1]
if need_quater:
quat = Quaternions.from_euler(np.radians(rot), order=order, world=world)
all_rotations.append(quat)
continue
elif order != canonical_order:
quat = Quaternions.from_euler(np.radians(rot), order=order, world=world)
rot = np.degrees(quat.euler(order=canonical_order))
all_rotations.append(rot)
rotations = np.concatenate(all_rotations, axis=1)
return Animation(rotations, positions, orients, offsets, parents, names, frametime)
def save(filename, anim, names=None, frametime=1.0/24.0, order='zyx', positions=False, orients=True):
"""
Saves an Animation to file as BVH
Parameters
----------
filename: str
File to be saved to
anim : Animation
Animation to save
names : [str]
List of joint names
order : str
Optional Specifier for joint order.
Given as string E.G 'xyz', 'zxy'
frametime : float
Optional Animation Frame time
positions : bool
Optional specfier to save bone
positions for each frame
orients : bool
Multiply joint orients to the rotations
before saving.
"""
if names is None:
names = ["joint_" + str(i) for i in range(len(anim.parents))]
with open(filename, 'w') as f:
t = ""
f.write("%sHIERARCHY\n" % t)
f.write("%sROOT %s\n" % (t, names[0]))
f.write("%s{\n" % t)
t += '\t'
f.write("%sOFFSET %f %f %f\n" % (t, anim.offsets[0,0], anim.offsets[0,1], anim.offsets[0,2]) )
f.write("%sCHANNELS 6 Xposition Yposition Zposition %s %s %s \n" %
(t, channelmap_inv[order[0]], channelmap_inv[order[1]], channelmap_inv[order[2]]))
for i in range(anim.shape[1]):
if anim.parents[i] == 0:
t = save_joint(f, anim, names, t, i, order=order, positions=positions)
t = t[:-1]
f.write("%s}\n" % t)
f.write("MOTION\n")
f.write("Frames: %i\n" % anim.shape[0]);
f.write("Frame Time: %f\n" % frametime);
#if orients:
# rots = np.degrees((-anim.orients[np.newaxis] * anim.rotations).euler(order=order[::-1]))
#else:
# rots = np.degrees(anim.rotations.euler(order=order[::-1]))
rots = np.degrees(anim.rotations.euler(order=order[::-1]))
poss = anim.positions
for i in range(anim.shape[0]):
for j in range(anim.shape[1]):
if positions or j == 0:
f.write("%f %f %f %f %f %f " % (
poss[i,j,0], poss[i,j,1], poss[i,j,2],
rots[i,j,ordermap[order[0]]], rots[i,j,ordermap[order[1]]], rots[i,j,ordermap[order[2]]]))
else:
f.write("%f %f %f " % (
rots[i,j,ordermap[order[0]]], rots[i,j,ordermap[order[1]]], rots[i,j,ordermap[order[2]]]))
f.write("\n")
def save_joint(f, anim, names, t, i, order='zyx', positions=False):
f.write("%sJOINT %s\n" % (t, names[i]))
f.write("%s{\n" % t)
t += '\t'
f.write("%sOFFSET %f %f %f\n" % (t, anim.offsets[i,0], anim.offsets[i,1], anim.offsets[i,2]))
if positions:
f.write("%sCHANNELS 6 Xposition Yposition Zposition %s %s %s \n" % (t,
channelmap_inv[order[0]], channelmap_inv[order[1]], channelmap_inv[order[2]]))
else:
f.write("%sCHANNELS 3 %s %s %s\n" % (t,
channelmap_inv[order[0]], channelmap_inv[order[1]], channelmap_inv[order[2]]))
end_site = True
for j in range(anim.shape[1]):
if anim.parents[j] == i:
t = save_joint(f, anim, names, t, j, order=order, positions=positions)
end_site = False
if end_site:
f.write("%sEnd Site\n" % t)
f.write("%s{\n" % t)
t += '\t'
f.write("%sOFFSET %f %f %f\n" % (t, 0.0, 0.0, 0.0))
t = t[:-1]
f.write("%s}\n" % t)
t = t[:-1]
f.write("%s}\n" % t)
return t
