Experimental module for SnekStudio attempting to understand and potentially replace the built-in MediaPipe module
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 

494 lines
19 KiB

class_name copyMediaPipe
extends Mod_Base
# -----------------------------------------------------------------------------
# Potentially configurable variables.
# -----------------------------------------------------------------------------
enum BlendshapeMode { NONE, MEDIA_PIPE, VRM_STANDARD }
var blendshape_mode := BlendshapeMode.VRM_STANDARD
var arm_rest_angle := 65
var interpolation_factor := 0.000000001 # Yes this value needs to be THAT small.
var rest_interpolation_factor := 0.2 # "Lerp about 80% of the way in one second."
var min_confidence_threshold := 0.85
var time_to_rest := 0.1 # Time without tracking data before returning to the rest pose.
# TODO: Change this via calibration!
var camera_transform := Transform3D(Basis(), Vector3(0.0, 0.0, 0.3))
# -----------------------------------------------------------------------------
# -----------------------------------------------------------------------------
# FIXME: Best to get this from the tracker process (if possible).
var camera_aspect_ratio := 4.0 / 3.0 # Logitech C920 default?
# TODO: Ensure that this works with the model offset from the world origin.
var ik_chains: Array[copyMediaPipe_IKChain] = []
@onready var tracking_root: Node3D = $TrackingRoot
@onready var head := {
last_data = null, # Most recent tracking data received.
last_received = INF, # How long ago it was received (in seconds).
tracker = $TrackingRoot/Head, # Node for visualizing tracking data.
rest_pose = Transform3D.IDENTITY, # Rest position of the head.
}
@onready var hands := {
left = {
last_data = null,
last_received = INF,
tracker = $TrackingRoot/LeftHand,
rest_pose = Transform3D.IDENTITY,
landmarks = [],
},
right = {
last_data = null,
last_received = INF,
tracker = $TrackingRoot/RightHand,
rest_pose = Transform3D.IDENTITY,
landmarks = [],
},
}
# -----------------------------------------------------------------------------
# -----------------------------------------------------------------------------
func _ready() -> void:
setup_hand_landmarks()
var dir = get_script().get_path().get_base_dir()
var path = dir.path_join("_tracker/Project/new_new_tracker.py")
python_process = KiriPythonWrapperInstance.new(path)
if not python_process.setup_python(false):
OS.alert("Failed to setup tracker dependencies!")
start_process()
# FIXME: Don't hardcode the video device.
set_video_device(get_video_devices()[0])
start_tracker()
func _exit_tree() -> void:
stop_tracker()
stop_process()
# Called after mod is initialized or model is changed.
func scene_init() -> void:
initialize_rest_pose()
initialize_ik_chains()
# Called before mod is removed, model is changed or application is shut down.
func scene_shutdown() -> void:
ik_chains = []
func _process(delta: float) -> void:
increase_last_received(delta)
if is_tracker_running():
receive_tracker_packets()
update_visual_trackers(delta)
update_ik_chains()
update_blendshapes()
## Sets up 21 nodes for the landmarks that make up hand/finger tracking.
func setup_hand_landmarks() -> void:
const landmark_scene := preload("Resources/debug_landmark.tscn")
for side in hands:
var hand = hands[side]
for i in 21:
var landmark := landmark_scene.instantiate()
hand.tracker.add_child(landmark)
hand.landmarks.append(landmark)
# -----------------------------------------------------------------------------
# Initialization functions that are called when a new model is loaded.
# -----------------------------------------------------------------------------
## Initialized the stored rest positions for the head and hands.
## Also applies a rotation to the arms so they're not T-posing.
func initialize_rest_pose() -> void:
var skel := get_skeleton()
if not skel: return
var head_idx := skel.find_bone("Head")
var head_rest := skel.get_bone_global_rest(head_idx)
# Move the tracking root such that it is at the height of the head.
tracking_root.transform = camera_transform * head_rest
head.rest_pose = tracking_root.transform.inverse() * head_rest
for side in hands:
var shoulder_idx := skel.find_bone(side.capitalize() + "Shoulder")
var hand_idx := skel.find_bone(side.capitalize() + "Hand")
var shoulder_rest := skel.get_bone_global_rest(shoulder_idx)
var hand_rest := skel.get_bone_global_rest(hand_idx)
# First, get relative transform of hand to shoulder.
var hand_to_shoulder := shoulder_rest.inverse() * hand_rest
# Next, rotate this relative transform by arm_rest_angle.
hand_to_shoulder = hand_to_shoulder.rotated(Vector3.LEFT, deg_to_rad(arm_rest_angle))
# Finally, put the relative transform back into skeleton-relative coordinates.
var new_hand_transform := shoulder_rest * hand_to_shoulder
hands[side].rest_pose = tracking_root.transform.inverse() * new_hand_transform
## Sets up the inverse kinematics chains to move the model depending on the location of the visual trackers.
func initialize_ik_chains() -> void:
ik_chains = []
var chain_spine := copyMediaPipe_IKChain.new()
chain_spine.skeleton = get_skeleton()
chain_spine.base_bone = "Hips"
chain_spine.tip_bone = "Head"
chain_spine.rotation_low = 0.0 * TAU
chain_spine.rotation_high = 1.0 * TAU
chain_spine.do_yaw = true
chain_spine.main_axis_of_rotation = Vector3.RIGHT
chain_spine.secondary_axis_of_rotation = Vector3.UP
chain_spine.pole_direction_target = Vector3.ZERO # No pole target.
chain_spine.tracker_object = head.tracker
chain_spine.yaw_scale = 0.25 # chest_yaw_scale (Unsure what this does.)
ik_chains.append(chain_spine)
var x_pole_dist = 10.0
var y_pole_dist = 5.0
var z_pole_dist = 10.0
var arm_rotation_axis = Vector3.UP
for side in hands:
var hand = hands[side]
var chain_hand := copyMediaPipe_IKChain.new()
chain_hand.skeleton = get_skeleton()
chain_hand.base_bone = side.capitalize() + "UpperArm"
chain_hand.tip_bone = side.capitalize() + "Hand"
chain_hand.rotation_low = 0.025 * TAU
chain_hand.rotation_high = 0.990 * TAU
chain_hand.do_yaw = false
chain_hand.do_bone_roll = true
chain_hand.secondary_axis_of_rotation = Vector3.UP
if side == "left":
chain_hand.main_axis_of_rotation = -arm_rotation_axis
chain_hand.pole_direction_target = Vector3(x_pole_dist, -y_pole_dist, -z_pole_dist)
chain_hand.tracker_object = hand.tracker
else:
chain_hand.main_axis_of_rotation = arm_rotation_axis
chain_hand.pole_direction_target = Vector3(-x_pole_dist, -y_pole_dist, -z_pole_dist)
chain_hand.tracker_object = hand.tracker
ik_chains.append(chain_hand)
# -----------------------------------------------------------------------------
# Functions to start/stop the PYTHON TRACKER PROCESS and communicate with it.
# -----------------------------------------------------------------------------
var python_process: KiriPythonWrapperInstance
func start_process() -> void:
python_process.start_process(false)
func stop_process() -> void:
python_process.stop_process()
func is_process_running() -> bool:
return python_process.get_status() == KiriPythonWrapperInstance.KiriPythonWrapperStatus.STATUS_RUNNING
# [{ name: String, backend: String, path: String, index: int }]
func get_video_devices() -> Array:
assert(is_process_running())
var devices = python_process.call_rpc_sync("enumerate_camera_devices", [])
return devices if devices is Array else []
func set_video_device(device) -> void:
assert(is_process_running())
var index: int = device.index if device else -1
python_process.call_rpc_sync("set_video_device_number", [ index ])
# -----------------------------------------------------------------------------
# Functions to start/stop the TRACKER and receive packets coming from it.
# -----------------------------------------------------------------------------
var base_port := 7098
var udp_server: PacketPeerUDP
var udp_server_port: int
func start_tracker() -> void:
assert(!is_tracker_running())
udp_server = PacketPeerUDP.new()
# Find a port number that's open to use.
udp_server_port = base_port
while udp_server.bind(udp_server_port, "127.0.0.1") != OK:
udp_server_port += 1
python_process.call_rpc_sync("set_udp_port_number", [ udp_server_port ])
python_process.call_rpc_sync("start_tracker", [])
func stop_tracker() -> void:
if !is_tracker_running(): return # Do nothing if tracker isn't running.
python_process.call_rpc_sync("stop_tracker", [])
udp_server.close()
udp_server = null
func is_tracker_running() -> bool:
return udp_server != null
func receive_tracker_packets() -> void:
assert(is_tracker_running())
while true:
var bytes := udp_server.get_packet()
if bytes.size() == 0: break
var data = JSON.parse_string(bytes.get_string_from_utf8())
if data is Dictionary: process_tracker_data(data)
# FIXME: Find out why we appear to always be processing 2 packets a frame.
# -----------------------------------------------------------------------------
# Functions to PROCESS and CONVERT the incoming TRACKER DATA.
# -----------------------------------------------------------------------------
func increase_last_received(delta: float) -> void:
head.last_received += delta
hands.left.last_received += delta
hands.right.last_received += delta
func process_tracker_data(data: Dictionary) -> void:
if "error" in data: on_tracker_error(data.error); return
if "status" in data: on_tracker_status(data.status); return
# Convert the arrays inside data to known data types like Vector3 and Transform3D.
data["face"]["transform"] = to_transform(data["face"]["transform"])
for side in data["hands"]:
var hand = data["hands"][side]
# Convert untyped array of arrays to typed Array[Vector3].
var image_landmarks = hand["image_landmarks"].map(to_vector)
var world_landmarks = hand["world_landmarks"].map(to_vector)
hand["image_landmarks"] = Array(image_landmarks, TYPE_VECTOR3, "", null)
hand["world_landmarks"] = Array(world_landmarks, TYPE_VECTOR3, "", null)
# Face matrix is in centimeters, convert to meters.
data["face"]["transform"].origin /= 100
# NOTE: Face confidence currently either 0.0 or 1.0.
if data["face"]["confidence"] > min_confidence_threshold:
head.last_data = data["face"]
head.last_received = 0.0
for side in hands:
var hand = hands[side]
var hand_data = data["hands"][side]
if hand_data["confidence"] > min_confidence_threshold:
var image_landmarks: Array[Vector3] = hand_data["image_landmarks"]
var world_landmarks: Array[Vector3] = hand_data["world_landmarks"]
# Mirror position on the X axis, since image landmarks are in view space.
for i in image_landmarks.size(): image_landmarks[i].x = (1 - image_landmarks[i].x)
# Unsure why, but world landmarks might be in a different coordinate system than expected?
var rotation_fix := Basis(Vector3.RIGHT, TAU / 2)
for i in world_landmarks.size(): world_landmarks[i] = rotation_fix * world_landmarks[i]
hand.last_data = hand_data
hand.last_received = 0.0
func on_tracker_status(status: String) -> void:
set_status(status)
func on_tracker_error(error: String) -> void:
print_log("Error: " + error)
func to_vector(array) -> Vector3:
return Vector3(array[0], array[1], array[2])
func to_transform(matrix) -> Transform3D:
return Transform3D(
Basis(Vector3(matrix[0][0], matrix[1][0], matrix[2][0]),
Vector3(matrix[0][1], matrix[1][1], matrix[2][1]),
Vector3(matrix[0][2], matrix[1][2], matrix[2][2])),
Vector3(matrix[0][3], matrix[1][3], matrix[2][3]))
# -----------------------------------------------------------------------------
# Functions for updating VISUAL TRACKERS and THE MODEL itself.
# -----------------------------------------------------------------------------
func update_visual_trackers(delta: float) -> void:
if head.last_received >= time_to_rest:
# Reset to rest pose transform.
head.tracker.transform = fi_slerp(head.tracker.transform,
head.rest_pose, rest_interpolation_factor, delta)
else:
head.tracker.transform = fi_slerp(head.tracker.transform,
head.last_data["transform"], interpolation_factor, delta)
# TODO: Don't automatically trust the handedness of the input data.
for side in hands:
var hand = hands[side]
if hand.last_received >= time_to_rest:
# Reset to rest pose transform.
hand.tracker.transform = fi_slerp(hand.tracker.transform,
hand.rest_pose, rest_interpolation_factor, delta)
else:
var image_landmarks: Array[Vector3] = hand.last_data["image_landmarks"]
var world_landmarks: Array[Vector3] = hand.last_data["world_landmarks"]
var hand_rotation := get_hand_rotation(side, world_landmarks)
var hand_origin := get_hand_viewspace_origin(image_landmarks, world_landmarks, 2.0) \
* Vector3(7.0, 7.0, 3.5) # FIXME: Fudge factor to match better with world space.
var target_transform := Transform3D(hand_rotation, hand_origin)
hand.tracker.transform = fi_slerp(hand.tracker.transform,
target_transform, interpolation_factor, delta)
# Translate landmarks so the origin is at the wrist.
var wrist_position := world_landmarks[0]
# World landmarks are in world space, so we have to "subtract" the hand rotation.
for i in world_landmarks.size():
var pos := world_landmarks[i] - wrist_position
hand.landmarks[i].position = hand_rotation.inverse() * pos
func update_ik_chains() -> void:
for chain in ik_chains:
chain.do_ik_chain()
func update_blendshapes() -> void:
const Blendshapes := preload("res://Mods/MediaPipe/MediaPipeController_BlendShapes.gd")
var model := get_model()
if (not model) or (not head.last_data): return
var data: Dictionary = head.last_data.blendshapes
var shape_dict: Dictionary
match blendshape_mode:
BlendshapeMode.MEDIA_PIPE: shape_dict = data
BlendshapeMode.VRM_STANDARD: shape_dict = \
Blendshapes.convert_mediapipe_shapes_to_vrm_standard(data)
# TODO: Blendshapes.apply_smoothing(...)
Blendshapes.fixup_eyes(shape_dict)
Blendshapes.apply_animations(model, shape_dict)
# -----------------------------------------------------------------------------
# Utility functions, currently only relating to update_visual_trackers.
# -----------------------------------------------------------------------------
# Indices of hand landmarks.
const WRIST := 0
const THUMB_CMC := 1
const THUMB_MCP := 2
const THUMB_IP := 3
const THUMB_TIP := 4
const INDEX_FINGER_MCP := 5
const INDEX_FINGER_PIP := 6
const INDEX_FINGER_DIP := 7
const INDEX_FINGER_TIP := 8
const MIDDLE_FINGER_MCP := 9
const MIDDLE_FINGER_PIP := 10
const MIDDLE_FINGER_DIP := 11
const MIDDLE_FINGER_TIP := 12
const RING_FINGER_MCP := 13
const RING_FINGER_PIP := 14
const RING_FINGER_DIP := 15
const RING_FINGER_TIP := 16
const PINKY_MCP := 17
const PINKY_PIP := 18
const PINKY_DIP := 19
const PINKY_TIP := 20
## Calculate the hand rotation from the hand tracking's world landmarks.
func get_hand_rotation(side: String, landmarks: Array[Vector3]) -> Basis:
var knuckles_center := (landmarks[INDEX_FINGER_MCP] + landmarks[RING_FINGER_TIP]) / 2
var wrist_to_knuckles := landmarks[WRIST].direction_to(knuckles_center)
var towards_thumb := landmarks[RING_FINGER_TIP].direction_to(landmarks[INDEX_FINGER_MCP])
var palm_forward: Vector3
if side == "left": palm_forward = towards_thumb.cross(wrist_to_knuckles)
if side == "right": palm_forward = wrist_to_knuckles.cross(towards_thumb)
return Basis.looking_at(palm_forward, wrist_to_knuckles)
## Attempt to figure out the hand origin in viewspace.
## `hand_to_head_scale` is a fudge value so that we can attempt
## to force the hand and head into the same scale range, roughly.
func get_hand_viewspace_origin(
image_landmarks: Array[Vector3],
_world_landmarks: Array[Vector3], # unused
hand_to_head_scale: float,
) -> Vector3:
# Values found through experimentation.
var known_distances := [
[ WRIST , THUMB_CMC , 0.053861 ],
[ THUMB_CMC , THUMB_MCP , 0.057096 ],
[ THUMB_MCP , THUMB_IP , 0.048795 ],
[ THUMB_IP , THUMB_TIP , 0.039851 ],
[ WRIST , INDEX_FINGER_MCP , 0.152538 ],
[ WRIST , RING_FINGER_TIP , 0.138711 ],
[ INDEX_FINGER_MCP , MIDDLE_FINGER_MCP , 0.029368 ],
[ MIDDLE_FINGER_MCP , MIDDLE_FINGER_TIP , 0.027699 ],
[ MIDDLE_FINGER_TIP , RING_FINGER_TIP , 0.032673 ],
]
# FIXME: Hardcoded fudge-factor
for d in known_distances: d[2] *= 0.25
# Iterate through known distances and add up the weighted average.
var fake_z_avg := 0.0
var total_avg_weight := 0.0
for d in known_distances:
var pt0 := image_landmarks[d[0]]
var pt1 := image_landmarks[d[1]]
# Figure out a weighted average based on how much the vector
# is facing the camera Z axis. Stuff facing into the camera
# has less accurate results, so weight it lower.
var normvec := (pt0 - pt1).normalized()
var weight := clampf(1.0 - 2.0 * abs(normvec[2]), 0.0, 1.0)
# Add to the average.
fake_z_avg += guess_depth_from_known_distance(
pt0, pt1, d[2] / hand_to_head_scale) * weight
total_avg_weight += weight
if abs(total_avg_weight) < 0.000001:
print("HEY THE THING HAPPENED", total_avg_weight)
# FIXME: Fudge value because I'm tired of this thing throwing
# exceptions all the time. Do an actual fix later.
total_avg_weight = 0.01
# Finish the average.
fake_z_avg = fake_z_avg / total_avg_weight
return ndc_to_viewspace(image_landmarks[0], -fake_z_avg)
## Figure out a depth value based on the distance between known
## normalized (clip-space) coordinates of landmarks, compared to what
## we would expect the average distance between those points to be.
func guess_depth_from_known_distance(left: Vector3, right: Vector3, distance: float) -> float:
var dist_clip := left - right
dist_clip.x *= camera_aspect_ratio # FIXME: Fudge factor
return 1.0 / (dist_clip.length() / distance)
func ndc_to_viewspace(v: Vector3, z_offset: float) -> Vector3:
# This (px, py) is pretty important and Google's
# documentation didn't give much useful info about it.
var px := 0.5
var py := 0.5
# These default to 1.0, 1.0 according to Google's docs.
# I guess that's probably fine for default camera stuff.
var fx := 1.0
var fy := camera_aspect_ratio
# Inverse equation from the section on NDC space here
# https://google.github.io/mediapipe/solutions/objectron.html#coordinate-systems
# https://web.archive.org/web/20220727063132/https://google.github.io/mediapipe/solutions/objectron.html#coordinate-systems
# which describes going from camera coordinates to NDC space. It's kinda
# ambiguous on terms, but this seems to work to get view space coordinates.
# With this, coordinates seem to be evenly scaled (between x/y and z) and in view space.
var z_scale := 1.0
var z := 1.0 / (-v[2] + (1.0 / z_offset) * z_scale)
var x := (v[0] - px) * z / fx
var y := (v[1] - py) * z / fy
return Vector3(x, y, z)
## Smoothly interpolates transforms in a framerate-independent way.
## For example, using a factor of 0.2, will move roughly 80% of the remaining distance in a second.
func fi_slerp(value: Transform3D, target: Transform3D, factor: float, delta: float) -> Transform3D:
return value.interpolate_with(target, 1 - factor ** delta)