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BvhToDM_Blender/BvhToDM.py
2020-02-12 16:53:00 +01:00

352 lines
14 KiB
Python

import bpy
import json
from mathutils import Vector
from typing import Union, List, Dict
import os
# Define the structure of the DeepMimic skeleton
child_dict = {
"root": ["spine", "right_thigh", "left_thigh"],
"spine": ["chest"],
"chest": ["head", "right_upper_arm", "left_upper_arm"],
"head": [],
"right_upper_arm": ["right_lower_arm"],
"right_lower_arm": ["right_hand"],
"right_hand": [],
"left_upper_arm": ["left_lower_arm"],
"left_lower_arm": ["left_hand"],
"left_hand": [],
"right_thigh": ["right_shin"],
"right_shin": ["right_foot"],
"right_foot": [],
"left_thigh": ["left_shin"],
"left_shin": ["left_foot"],
"left_foot": [],
}
# Joints used in the DM frame definition.
joints = [
"seconds", "hip", "hip", "chest", "neck", "right hip", "right knee", "right ankle",
"right shoulder", "right elbow", "left hip", "left knee", "left ankle", "left shoulder",
"left elbow"
]
# Order of which the DeepMimicSkeleton bones need to be added to frame data.
bone_names = [
"chest", "head", "right_thigh", "right_shin", "right_foot",
"right_upper_arm", "right_lower_arm", "left_thigh", "left_shin", "left_foot", "left_upper_arm",
"left_lower_arm"
]
# All 1D joints
joints_1d = ["right_shin", "left_shin", "right_lower_arm", "left_lower_arm"]
# Define ankles in order to do correct quaternion adjustment.
ankles = ["right_foot", "left_foot"]
class BoneConstructionData:
def __init__(self, target_name: str,
inherit_bone_length: bool,
inherit_bone_pos: bool,
use_connect: bool,
bone_direction_vec: List[float] = [0.0, 0.0, 1.0],
use_IK: bool = False,
use_DT: bool = False,
IK_chain_length: int = 0):
self.target_name = target_name
self.inherit_bone_length = inherit_bone_length
self.inherit_bone_pos = inherit_bone_pos
self.use_connect = use_connect
self.bone_direction_vec = bone_direction_vec
self.use_IK = use_IK
self.use_DT = use_DT
self.IK_chain_length = IK_chain_length
class BvhToDMSettings:
def __init__(self, bonedict: Dict[str, BoneConstructionData], target_name: str):
self.bonedict = bonedict
self.child_dict = child_dict
self.target_name = target_name
self.skel_name = "DeepMimicSkeleton"
self.translation_scale = 1.0
self.output_path = os.path.dirname(os.path.realpath(__file__))
self.output_file_name = "output.txt"
class BvhToDM:
def __init__(self, settings: BvhToDMSettings):
self.settings = settings
@staticmethod
def tail_relative(bone, rel_vec: List[float]):
bone.tail = [bone.head[x] + rel_vec[x] for x in range(3)]
def find_parent(self, bone_name) -> Union[str, None]:
for bone in self.settings.child_dict.keys():
if bone_name in self.settings.child_dict[bone]:
return bone
return None
def find_child(self, bone_name) -> Union[str, None]:
result = self.settings.child_dict[bone_name]
if len(result) == 1:
return result[0]
else:
return None
def generate_humanoid_skeleton(self):
# First fill up dictionary with edit_bone positions
# (Since it seems to be difficult to read the edit_bones of an armature while editing another one...)
target_bone_head_dict = {}
bpy.data.objects[self.settings.target_name].select_set(True)
if bpy.ops.object.mode_set.poll():
bpy.ops.object.mode_set(mode='EDIT')
for edit_bone in bpy.context.object.data.edit_bones:
target_bone_head_dict[edit_bone.name] = [x for x in edit_bone.head]
bpy.ops.object.mode_set(mode='OBJECT')
# Add the armature
bpy.ops.object.armature_add(enter_editmode=True)
obj = bpy.data.objects["Armature"]
obj.name = self.settings.skel_name
# Rename armature
armature = obj.data
armature.name = self.settings.skel_name
# Delete first auto-generated bone
bpy.ops.armature.select_all(action='SELECT')
bpy.ops.armature.delete()
# Cosntruct skeleton
for bone_name in self.settings.bonedict.keys():
construction_data = self.settings.bonedict[bone_name]
if bone_name == "root":
root = armature.edit_bones.new("root")
root.tail = (0.0, 0.0, 0.001)
else:
bone = armature.edit_bones.new(bone_name)
parent = self.find_parent(bone_name)
if parent is not None:
bone.parent = armature.edit_bones[parent]
bone.use_connect = construction_data.use_connect
if construction_data.inherit_bone_pos:
bone.head = target_bone_head_dict[construction_data.target_name]
if construction_data.inherit_bone_length:
length = bpy.data.objects[self.settings.target_name].data.bones[construction_data.target_name].length
self.tail_relative(bone, [length * x for x in construction_data.bone_direction_vec])
else:
# TODO: find out some way to guess the correct bone lengths if there are no corresponding bones in the target armature...
if bone_name in ["spine", "chest", "head"]:
self.tail_relative(bone, [0.0, 0.0, 0.22])
pass
def constrain_DM_skeleton(self):
if bpy.ops.object.mode_set.poll():
bpy.ops.object.mode_set(mode='POSE')
# Note that pose_bones are under: bpy.data.objects[...].pose.bones
skel = bpy.data.objects[self.settings.skel_name]
# Root
root_con = skel.pose.bones['root'].constraints.new('COPY_TRANSFORMS')
root_con.target = bpy.data.objects[self.settings.target_name]
root_con.subtarget = self.settings.bonedict['root'].target_name
# Spine
spine_con = skel.pose.bones['spine'].constraints.new('COPY_ROTATION')
spine_con.target = bpy.data.objects[self.settings.target_name]
spine_con.subtarget = self.settings.bonedict['spine'].target_name
# Fixing rotation in elbow and knee joints:
# 1) limit rotation constraint
# 2) y- and z-rotations constrain from 0 to 0 degrees. "Fixed"
# 3) Elbows: limit rotation in "Local space" from -180 to 0 degrees.
# Knees: from 0 to 180 degrees
# Knees
rightshin = skel.pose.bones['right_shin']
rightshin.ik_max_x = 3.1415
rightshin.ik_min_x = 0
rightshin.use_ik_limit_x = True
rightshin.lock_ik_y = True
rightshin.lock_ik_z = True
rightshin.rotation_mode = 'AXIS_ANGLE'
leftshin = skel.pose.bones['left_shin']
leftshin.ik_max_x = 3.1415
leftshin.ik_min_x = 0
leftshin.use_ik_limit_x = True
leftshin.lock_ik_y = True
leftshin.lock_ik_z = True
leftshin.rotation_mode = 'AXIS_ANGLE'
# Elbows
right_lower_arm = skel.pose.bones['right_lower_arm']
right_lower_arm.ik_max_x = 0
right_lower_arm.ik_min_x = -3.1415
right_lower_arm.use_ik_limit_x = True
right_lower_arm.lock_ik_y = True
right_lower_arm.lock_ik_z = True
right_lower_arm.rotation_mode = 'AXIS_ANGLE'
left_lower_arm = skel.pose.bones['left_lower_arm']
left_lower_arm.ik_max_x = 0
left_lower_arm.ik_min_x = -3.1415
left_lower_arm.use_ik_limit_x = True
left_lower_arm.lock_ik_y = True
left_lower_arm.lock_ik_z = True
left_lower_arm.rotation_mode = 'AXIS_ANGLE'
# IK settings
skel.pose.ik_solver = "ITASC"
skel.pose.ik_param.mode = "SIMULATION"
def _scale_skeleton(self):
"""Old method: do not use.
"""
# Scale so that the distance from ankle to shoulders is the same
# Set both objects to edit mode
if bpy.ops.object.mode_set.poll():
bpy.ops.object.mode_set(mode='EDIT')
shoulder_DM = "right_upper_arm"
shoulder_mocap = "ShoulderRight"
ankle_DM = "right_foot"
ankle_mocap = "AnkleRight"
DMS = bpy.data.armatures['DeepMimicSkeleton']
mocap_skel = bpy.data.armatures['rotation_prob']
# Only take into account z-component
mocap_height = mocap_skel.bones[shoulder_mocap].head_local[2] - mocap_skel.bones[ankle_mocap].head_local[2]
DM_height = DMS.bones[shoulder_DM].head_local[2] - DMS.bones[ankle_DM].head_local[2]
scale_factor = mocap_height/DM_height
# Select all bones
bpy.data.objects['DMS'].select_set(True)
bpy.ops.armature.select_all(action='SELECT')
# Scale
bpy.ops.transform.resize(value=(scale_factor, scale_factor, scale_factor))
def damped_track(self, bone: str, target_bone: str):
constraint = bpy.data.objects[self.settings.skel_name].pose.bones[bone].constraints.new('DAMPED_TRACK')
constraint.target = bpy.data.objects[self.settings.target_name]
constraint.subtarget = target_bone
constraint.head_tail = 1.0
def follow_mocap_damped_tracks(self):
for bone in self.settings.bonedict.keys():
bone_data = self.settings.bonedict[bone]
if bone_data.use_DT:
self.damped_track(bone, bone_data.target_name)
def inverse_kinematic_constraint(self, bone: str, target_bone: str, chain_count: int):
constraint = bpy.data.objects[self.settings.skel_name].pose.bones[bone].constraints.new('IK')
constraint.target = bpy.data.objects[self.settings.target_name]
constraint.subtarget = target_bone
constraint.use_tail = True
constraint.use_location = True
constraint.use_stretch = True
constraint.iterations = 500
constraint.chain_count = chain_count
def follow_mocap_IK(self):
for bone in self.settings.bonedict.keys():
bone_data = self.settings.bonedict[bone]
if bone_data.use_IK:
self.inverse_kinematic_constraint(
bone,
self.settings.bonedict[self.find_child(bone)].target_name,
bone_data.IK_chain_length
)
# TODO: find out why these adjustments are necessary.
# Probably has to do with:
# 1) In which direction the bone's rest position is defined.
# 2) The difference in worldframes. (Different axes between Blender and DeepMimic.)
@staticmethod
def quat_bvh_to_DM(quat):
# transform x -> -z and z -> -x, except for ankles and root!
return [quat[0], -quat[3], -quat[2], -quat[1]]
@staticmethod
def quat_bvh_to_DM_ankles(quat):
# transform x -> -z and z -> x
return [quat[0], quat[3], -quat[2], quat[1]]
@staticmethod
def quat_bvh_to_DM_root(quat):
return [quat[0], quat[3], quat[2], -quat[1]]
@staticmethod
def pos_blender_DM(pos, scale):
# y -> z, z -> -y?
return [-scale*pos[1], scale*pos[2], -scale*pos[0]]
def generate_frame(self, translation_scale):
arm = bpy.data.objects[self.settings.skel_name]
result = []
result.append(1.0 / bpy.context.scene.render.fps)
pos = self.pos_blender_DM(arm.pose.bones['root'].head, translation_scale)
result.extend(pos)
root_quat = self.quat_bvh_to_DM_root(arm.pose.bones['root'].rotation_quaternion)
result.extend(root_quat)
for bone_name in bone_names:
if bone_name in joints_1d:
# invert knee angles (no clue why)
if bone_name in joints_1d[:2]:
angle = -arm.pose.bones[bone_name].rotation_axis_angle[0]
else:
angle = arm.pose.bones[bone_name].rotation_axis_angle[0]
result.append(angle)
else:
# TODO: these rotations are absolute rotations! But we need local rotations... In the local bone frame...
if bone_name in ankles:
quat_DM = self.quat_bvh_to_DM_ankles(arm.pose.bones[bone_name].rotation_quaternion)
else:
quat_DM = self.quat_bvh_to_DM(arm.pose.bones[bone_name].rotation_quaternion)
result.extend([x for x in quat_DM])
return result
def generate_frames(self, translation_scale):
if bpy.ops.object.mode_set.poll():
bpy.ops.object.mode_set(mode='EDIT')
# Select all bones
bpy.data.objects[self.settings.skel_name].select_set(True)
bpy.ops.armature.select_all(action='SELECT')
if bpy.ops.object.mode_set.poll():
bpy.ops.object.mode_set(mode='POSE')
frames = []
loopText = "none"
for frame in range(bpy.context.scene.frame_start, bpy.context.scene.frame_end + 1):
# for frame in range(bpy.context.scene.frame_end + 1):
bpy.context.scene.frame_set(frame)
# Apply visual transform to pose
bpy.ops.pose.visual_transform_apply()
# bpy.context.view_layer.update()
frames.append(self.generate_frame(translation_scale))
# Output in dictionary format for easy json dump
outputDict = {
"Loop": loopText, # "none" or "wrap"
"Frames": frames
}
return json.dumps(outputDict, indent=4)
def run(self):
self.generate_humanoid_skeleton()
self.constrain_DM_skeleton()
self.follow_mocap_damped_tracks()
self.follow_mocap_IK()
# Save all quaternions in DeepMimic format, frame per frame!
generated_text = self.generate_frames(self.settings.translation_scale)
# print(generated_text)
with open(self.settings.output_path + "/" + self.settings.output_file_name, "w") as output:
output.write(generated_text)