def step_physics(task):
dt = globalClock.getDt()
physics.doPhysics(dt)
return task.cont
s.taskMgr.add(step_physics, 'physics simulation')
# A physical object in the simulation
node = BulletRigidBodyNode('Box')
node.setMass(1.0)
node.addShape(BulletSphereShape(1))
physics.attachRigidBody(node)
# Attaching the physical object in the scene graph and adding
# a visible model to it
np = s.render.attachNewNode(node)
np.setPos(0, 0, 0)
m = loader.loadModel("models/smiley")
m.reparentTo(np)
# Let's actually see what's happening
base.cam.setPos(0, -10, 0)
base.cam.lookAt(0, 0, 0)
# Give the object a nudge and run the program
node.apply_impulse(Vec3(0, 1, 0), Point3(0, 0, 0))
s.run()
def step_physics(task):
dt = globalClock.getDt()
physics.doPhysics(dt)
return task.cont
s.taskMgr.add(step_physics, 'physics simulation')
# A physical object in the simulation
node = BulletRigidBodyNode('Box')
node.setMass(1.0)
node.addShape(BulletSphereShape(1))
# Attaching the physical object in the scene graph and adding
# a visible model to it
np = s.render.attachNewNode(node)
np.set_pos(0, 0, 0)
np.set_hpr(45, 0, 45)
m = loader.loadModel("models/smiley")
m.reparentTo(np)
physics.attachRigidBody(node)
# Let's actually see what's happening
base.cam.setPos(0, -10, 0)
base.cam.lookAt(0, 0, 0)
# Give the object a nudge and run the program
# the impulse vector is in world space, the position at which it is
# applied is in object space.
node.apply_impulse(Vec3(0, 0, 1), Point3(1, 0, 0))
node.apply_impulse(Vec3(0, 0, -1), Point3(-1, 0, 0))
s.run()
physics = BulletWorld()
physics.setGravity(Vec3(0, 0, 0))
def step_physics(task):
dt = globalClock.getDt()
physics.doPhysics(dt)
return task.cont
s.taskMgr.add(step_physics, 'physics simulation')
# A physical object in the simulation
node = BulletRigidBodyNode('Box')
node.setMass(1.0)
node.addShape(BulletSphereShape(1))
physics.attachRigidBody(node)
# Attaching the physical object in the scene graph and adding
# a visible model to it
np = s.render.attachNewNode(node)
np.setPos(0, 0, 0)
m = loader.loadModel("models/smiley")
m.reparentTo(np)
# Let's actually see what's happening
base.cam.setPos(0, -10, 0)
base.cam.lookAt(0, 0, 0)
# Give the object a nudge and run the program
node.apply_impulse(Vec3(0,1,0), Point3(0,0,0))
s.run()
class Vehicle:
def __init__(self, app, model_name):
model_file_name = 'assets/cars/{}/{}.bam'.format(
model_name, model_name)
self.app = app
def animation_path(model, animation):
base_path = 'assets/cars/animations/{}/{}-{}.bam'
return base_path.format(model, model, animation)
self.model = Actor(
model_file_name,
{
# AIRBRAKE: 'assets/cars/animations/{}-{}.bam'.format(model_name, AIRBRAKE),
# AIRBRAKE: animation_path(model_name, AIRBRAKE),
# STABILIZER_FINS: animation_path(model_name, STABILIZER_FINS),
})
self.model.enableBlend()
self.model.setControlEffect(AIRBRAKE, 1)
self.model.setControlEffect(STABILIZER_FINS, 1)
# FIXME: This code fails due to a bug in Actor
# airbrake_joints = [joint.name
# for joint in self.model.getJoints()
# if joint.name.startswith(AIRBRAKE)
# ]
# self.model.makeSubpart(AIRBRAKE, airbrake_joints)
# stabilizer_joints = [joint.name
# for joint in self.model.getJoints()
# if joint.name.startswith(STABILIZER_FINS)
# ]
# self.model.makeSubpart(STABILIZER_FINS, stabilizer_joints)
puppet = self.app.loader.load_model(model_file_name)
puppet.find("**/armature").hide()
puppet.reparentTo(self.model)
# Get the vehicle data
self.vehicle_data = VehicleData(puppet, model_name, 'cars')
# Configure the physics node
self.physics_node = BulletRigidBodyNode('vehicle')
self.physics_node.set_friction(self.vehicle_data.friction)
self.physics_node.set_linear_sleep_threshold(0)
self.physics_node.set_angular_sleep_threshold(0)
self.physics_node.setCcdMotionThreshold(1e-7)
self.physics_node.setCcdSweptSphereRadius(0.5)
self.physics_node.setMass(self.vehicle_data.mass)
shape = BulletConvexHullShape()
for geom_node in self.model.find_all_matches("**/+GeomNode"):
for geom in geom_node.node().get_geoms():
vertices = GeomVertexReader(geom.get_vertex_data(), 'vertex')
while not vertices.is_at_end():
v_geom = vertices.getData3f()
v_model = self.model.get_relative_point(geom_node, v_geom)
shape.add_point(v_model)
self.physics_node.add_shape(shape)
self.vehicle = NodePath(self.physics_node)
self.vehicle.set_collide_mask(CM_VEHICLE | CM_COLLIDE)
self.model.reparent_to(self.vehicle)
# Navigational aids
self.target_node = self.app.loader.load_model('models/zup-axis')
self.target_node.reparent_to(self.model)
self.target_node.set_scale(1)
self.target_node.set_render_mode_wireframe()
self.target_node.hide()
self.delta_node = self.app.loader.load_model('models/smiley')
self.delta_node.set_pos(1, 10, 1)
self.delta_node.reparent_to(base.cam)
self.delta_node.hide()
self.airbrake_state = 0.0
self.airbrake_factor = 0.5
self.airbrake_speed = 1 / self.vehicle_data.airbrake_duration
self.stabilizer_fins_state = 0.0
self.stabilizer_fins_speed = 1 / self.vehicle_data.stabilizer_fins_duration
self.centroid = base.loader.load_model('models/smiley')
self.centroid.reparent_to(self.vehicle)
self.centroid.hide()
# Gyro sound
sound_file = 'assets/cars/{}/{}.wav'.format(
model_name,
GYROSCOPE_SOUND,
)
sound = base.audio3d.load_sfx(sound_file)
self.model.set_python_tag(GYROSCOPE_SOUND, sound)
base.audio3d.attach_sound_to_object(sound, self.model)
sound.set_volume(0)
sound.set_play_rate(0)
sound.set_loop(True)
sound.play()
# Thruster limiting
self.thruster_state = 0.0
self.thruster_heat = 0.0
for repulsor in self.vehicle_data.repulsor_nodes:
self.add_repulsor(repulsor, model_name)
for thruster in self.vehicle_data.thruster_nodes:
self.add_thruster(thruster, model_name)
# ECU data storage from frame to frame
self.last_flight_height = None
# FIXME: Move into a default controller
self.inputs = {
# Repulsors
REPULSOR_ACTIVATION: 0.0,
ACCELERATE: 0.0,
TURN: 0.0,
STRAFE: 0.0,
HOVER: 0.0,
FULL_REPULSORS: False,
# Gyro
ACTIVE_STABILIZATION_ON_GROUND: PASSIVE,
ACTIVE_STABILIZATION_CUTOFF_ANGLE: PASSIVE,
ACTIVE_STABILIZATION_IN_AIR: PASSIVE,
TARGET_ORIENTATION: Vec3(0, 0, 0),
# Thrust
THRUST: 0.0,
# Air foils
AIRBRAKE: 0.0,
STABILIZER_FINS: 0.0,
}
self.sensors = {}
self.commands = {}
def np(self):
return self.vehicle
def place(self, spawn_point):
# FIXME: Pass a root node to __init__ instead
self.vehicle.reparent_to(self.app.environment.model)
connector = self.model.find("**/" + SPAWN_POINT_CONNECTOR)
self.vehicle.set_hpr(-connector.get_hpr(spawn_point))
self.vehicle.set_pos(-connector.get_pos(spawn_point))
self.app.environment.add_physics_node(self.physics_node)
def set_inputs(self, inputs):
self.inputs = inputs
def add_repulsor(self, node, model_name):
ground_contact = self.app.loader.load_model(
"assets/effect/repulsorhit.egg")
ground_contact.set_scale(1)
ground_contact.reparent_to(self.app.render)
node.set_python_tag('ray_end', ground_contact)
sound_file = 'assets/cars/{}/{}.wav'.format(
model_name,
REPULSOR_SOUND,
)
sound = base.audio3d.load_sfx(sound_file)
node.set_python_tag(REPULSOR_SOUND, sound)
base.audio3d.attach_sound_to_object(sound, node)
sound.set_volume(0)
sound.set_play_rate(0)
sound.set_loop(True)
sound.play()
def add_thruster(self, node, model_name):
node.set_python_tag(THRUSTER_POWER, 0.0)
node.set_python_tag(THRUSTER_OVERHEATED, False)
# Basic jet sound
sound_file = 'assets/cars/{}/{}.wav'.format(
model_name,
THRUSTER_SOUND,
)
sound = base.audio3d.load_sfx(sound_file)
node.set_python_tag(THRUSTER_SOUND, sound)
base.audio3d.attach_sound_to_object(sound, node)
sound.set_volume(0)
sound.set_play_rate(0)
sound.set_loop(True)
sound.play()
# Overheating sound
sound_file = 'assets/cars/{}/{}.wav'.format(
model_name,
THRUSTER_OVERHEAT_SOUND,
)
sound = base.audio3d.load_sfx(sound_file)
node.set_python_tag(THRUSTER_OVERHEAT_SOUND, sound)
base.audio3d.attach_sound_to_object(sound, node)
def game_loop(self):
self.gather_sensors()
self.ecu()
self.apply_air_drag()
self.apply_repulsors()
self.apply_gyroscope()
self.apply_thrusters()
self.apply_airbrake()
self.apply_stabilizer_fins()
def gather_sensors(self):
# Gather data repulsor ray collisions with ground
repulsor_data = []
for node in self.vehicle_data.repulsor_nodes:
data = RepulsorData()
repulsor_data.append(data)
max_distance = node.get_python_tag(ACTIVATION_DISTANCE)
data.position = node.get_pos(self.vehicle)
data.direction = self.app.render.get_relative_vector(
node,
Vec3(0, 0, -max_distance),
)
# FIXME: `self.app.environment.physics_world` is ugly.
feeler = self.app.environment.physics_world.ray_test_closest(
base.render.get_relative_point(self.vehicle, data.position),
base.render.get_relative_point(self.vehicle,
data.position + data.direction),
CM_TERRAIN,
)
if feeler.has_hit():
data.active = True
data.fraction = feeler.get_hit_fraction()
data.contact = self.vehicle.get_relative_point(
self.app.render,
feeler.get_hit_pos(),
)
else:
data.active = False
data.fraction = 1.0
# Find the local ground's normal vector
local_up = False
contacts = [
data.contact for data in repulsor_data
if data.active and self.inputs[REPULSOR_ACTIVATION]
]
if len(contacts) > 2:
local_up = True
target_mode = self.inputs[ACTIVE_STABILIZATION_ON_GROUND]
# We can calculate a local up as the smallest base vector of the
# point cloud of contacts.
centroid = reduce(lambda a, b: a + b, contacts) / len(contacts)
covariance = [
[c.x, c.y, c.z]
for c in [contact - centroid for contact in contacts]
][0:3] # We need exactly 3, no PCA yet. :(
eigenvalues, eigenvectors = numpy.linalg.eig(
numpy.array(covariance))
# FIXME: These few lines look baaaad...
indexed_eigenvalues = enumerate(eigenvalues)
def get_magnitude(indexed_element):
index, value = indexed_element
return abs(value)
sorted_indexed_eigenvalues = sorted(
indexed_eigenvalues,
key=get_magnitude,
)
# The smallest eigenvalue leads to the ground plane's normal
up_vec_idx, _ = sorted_indexed_eigenvalues[0]
up_vec = VBase3(*eigenvectors[:, up_vec_idx])
# Point into the upper half-space
if up_vec.z < 0:
up_vec *= -1
# Calculate the forward of the centroid
centroid_forward = Vec3(0, 1,
0) - up_vec * (Vec3(0, 1, 0).dot(up_vec))
# FIXME: Huh?
forward_planar = centroid_forward - up_vec * (
centroid_forward.dot(up_vec))
# Now let's orient and place the centroid
self.centroid.set_pos(self.vehicle, (0, 0, 0))
self.centroid.heads_up(forward_planar, up_vec)
self.centroid.set_pos(self.vehicle, centroid)
# Flight height for repulsor attenuation
flight_height = -self.centroid.get_z(self.vehicle)
if self.last_flight_height is not None:
climb_speed = (flight_height -
self.last_flight_height) / globalClock.dt
else:
climb_speed = 0
self.last_flight_height = flight_height
else:
local_up = False
self.last_flight_height = None
flight_height = 0.0
climb_speed = 0.0
# Air drag
movement = self.physics_node.get_linear_velocity()
drag_coefficient = self.vehicle_data.drag_coefficient
drag_area = self.vehicle_data.drag_area + \
self.vehicle_data.airbrake_area * self.airbrake_state + \
self.vehicle_data.stabilizer_fins_area * self.stabilizer_fins_state
air_density = self.app.environment.env_data.air_density
air_speed = -self.vehicle.get_relative_vector(
base.render,
movement,
)
# drag_force = 1/2*drag_coefficient*mass_density*area*flow_speed**2
result = Vec3(air_speed)
result = (result**3) / result.length()
result.componentwise_mult(drag_area)
result.componentwise_mult(self.vehicle_data.drag_coefficient)
drag_force = result * 1 / 2 * air_density
self.sensors = {
CURRENT_ORIENTATION: self.vehicle.get_hpr(self.app.render),
CURRENT_MOVEMENT: movement,
CURRENT_ROTATION: self.physics_node.get_angular_velocity(),
LOCAL_DRAG_FORCE: drag_force,
REPULSOR_DATA: repulsor_data,
LOCAL_UP: local_up,
FLIGHT_HEIGHT: flight_height,
CLIMB_SPEED: climb_speed,
}
def ecu(self):
repulsor_target_angles = self.ecu_repulsor_reorientation()
repulsor_activation, delta_height, projected_delta_height, \
power_frac_needed = self.ecu_repulsor_activation()
gyro_rotation = self.ecu_gyro_stabilization()
thruster_activation = [
self.inputs[THRUST] for _ in self.vehicle_data.thruster_nodes
]
airbrake = self.inputs[AIRBRAKE]
stabilizer_fins = self.inputs[STABILIZER_FINS]
self.commands = {
# Steering commands
REPULSOR_TARGET_ORIENTATIONS: repulsor_target_angles,
REPULSOR_ACTIVATION: repulsor_activation,
GYRO_ROTATION: gyro_rotation,
THRUSTER_ACTIVATION: thruster_activation,
AIRBRAKE: airbrake,
STABILIZER_FINS: stabilizer_fins,
# ECU data output; Interesting numbers we found along the way.
HEIGHT_OVER_TARGET: delta_height,
HEIGHT_OVER_TARGET_PROJECTED: projected_delta_height,
REPULSOR_POWER_FRACTION_NEEDED: power_frac_needed,
}
def ecu_repulsor_reorientation(self):
# Calculate effective repulsor motion blend values
accelerate = self.inputs[ACCELERATE]
turn = self.inputs[TURN]
strafe = self.inputs[STRAFE]
hover = self.inputs[HOVER]
length = sum([abs(accelerate), abs(turn), abs(strafe), hover])
if length > 1:
accelerate /= length
turn /= length
strafe /= length
hover /= length
# Split the turn signal into animation blend factors
if turn > 0.0:
turn_left = 0.0
turn_right = turn
else:
turn_left = -turn
turn_right = 0.0
# Blend the repulsor angle
repulsor_target_angles = []
for node in self.vehicle_data.repulsor_nodes:
acc_angle = -(node.get_python_tag(ACCELERATE)) * accelerate
turn_left_angle = node.get_python_tag(TURN_LEFT) * turn_left
turn_right_angle = node.get_python_tag(TURN_RIGHT) * turn_right
strafe_angle = node.get_python_tag(STRAFE) * strafe
hover_angle = node.get_python_tag(HOVER) * hover
angle = acc_angle + turn_left_angle + turn_right_angle + \
strafe_angle + hover_angle
repulsor_target_angles.append(angle)
return repulsor_target_angles
def ecu_repulsor_activation(self):
# Do we know how high we are flying?
if self.sensors[LOCAL_UP]:
tau = self.inputs[TARGET_FLIGHT_HEIGHT_TAU]
# What would we be at in tau seconds if we weren't using repulsors?
flight_height = self.sensors[FLIGHT_HEIGHT]
target_flight_height = self.inputs[TARGET_FLIGHT_HEIGHT]
delta_height = flight_height - target_flight_height
gravity_z = self.centroid.get_relative_vector(
self.app.render,
self.app.environment.physics_world.get_gravity(),
).get_z()
# Since gravity is an acceleration
gravity_h = 1 / 2 * gravity_z * tau**2
climb_rate = self.sensors[CLIMB_SPEED] * tau
projected_delta_height = delta_height + gravity_h + climb_rate
# Are we sinking?
if projected_delta_height <= 0:
# Our projected height will be under our target height, so we
# will need to apply the repulsors to make up the difference.
# How much climb can each repulsor provide at 100% power right
# now?
max_powers = [
node.get_python_tag(FORCE)
for node in self.vehicle_data.repulsor_nodes
]
transferrable_powers = [
max_power * cos(0.5 * pi * data.fraction)
for max_power, data in zip(
max_powers,
self.sensors[REPULSOR_DATA],
)
]
angle_ratios = [
cos(node.get_quat(self.vehicle).get_angle_rad())
for node in self.vehicle_data.repulsor_nodes
]
angled_powers = [
power * ratio
for power, ratio in zip(transferrable_powers, angle_ratios)
]
# We don't want to activate the repulsors unevenly, so we'll
# have to go by the weakest link.
total_angled_power = min(angled_powers) * len(angled_powers)
# How high can we climb under 100% repulsor power?
max_climb = 1 / 2 * total_angled_power * tau**2 / self.vehicle_data.mass
# The fraction of power needed to achieve the desired climb
power_frac_needed = -projected_delta_height / max_climb
# ...and store it.
repulsor_activation = [
power_frac_needed for _ in self.vehicle_data.repulsor_nodes
]
else:
# We're not sinking.
repulsor_activation = [
0.0 for _ in self.vehicle_data.repulsor_nodes
]
power_frac_needed = 0.0
else: # We do not have ground contact.
repulsor_activation = [
0.0 for _ in self.vehicle_data.repulsor_nodes
]
delta_height = 0.0
projected_delta_height = 0.0
power_frac_needed = 0.0
# The driver gives 100% repulsor power, no matter how high we are, or
# whether we even have ground contact.
if self.inputs[FULL_REPULSORS]:
repulsor_activation = [
self.inputs[REPULSOR_ACTIVATION]
for _ in self.vehicle_data.repulsor_nodes
]
return repulsor_activation, delta_height, projected_delta_height,\
power_frac_needed
def ecu_gyro_stabilization(self):
# Active stabilization and angular dampening
# FIXME: Get from self.inputs
tau = 0.2 # Seconds until target orientation is reached
if self.sensors[LOCAL_UP]:
target_mode = self.inputs[ACTIVE_STABILIZATION_ON_GROUND]
else:
target_mode = self.inputs[ACTIVE_STABILIZATION_IN_AIR]
if target_mode == TO_HORIZON:
# Stabilize to the current heading, but in a horizontal
# orientation
self.target_node.set_hpr(
self.app.render,
self.vehicle.get_h(),
0,
0,
)
elif target_mode == TO_GROUND:
# Stabilize towards the local up
self.target_node.set_hpr(self.centroid, (0, 0, 0))
if target_mode != PASSIVE:
xyz_driver_modification = self.inputs[TARGET_ORIENTATION]
hpr_driver_modification = VBase3(
xyz_driver_modification.z,
xyz_driver_modification.x,
xyz_driver_modification.y,
)
self.target_node.set_hpr(
self.target_node,
hpr_driver_modification,
)
# Now comes the math.
orientation = self.vehicle.get_quat(self.app.render)
target_orientation = self.target_node.get_quat(self.app.render)
delta_orientation = target_orientation * invert(orientation)
self.delta_node.set_quat(invert(delta_orientation))
delta_angle = delta_orientation.get_angle_rad()
if abs(delta_angle) < (pi / 360 * 0.1) or isnan(delta_angle):
delta_angle = 0
axis_of_torque = VBase3(0, 0, 0)
else:
axis_of_torque = delta_orientation.get_axis()
axis_of_torque.normalize()
axis_of_torque = self.app.render.get_relative_vector(
self.vehicle,
axis_of_torque,
)
if delta_angle > pi:
delta_angle -= 2 * pi
# If the mass was standing still, this would be the velocity that
# has to be reached to achieve the targeted orientation in tau
# seconds.
target_angular_velocity = axis_of_torque * delta_angle / tau
else: # `elif target_mode == PASSIVE:`, since we might want an OFF mode
# Passive stabilization, so this is the pure commanded impulse
target_angular_velocity = self.app.render.get_relative_vector(
self.vehicle,
self.inputs[TARGET_ORIENTATION] * tau / pi,
)
# But we also have to cancel out the current velocity for that.
angular_velocity = self.physics_node.get_angular_velocity()
countering_velocity = -angular_velocity
# An impulse of 1 causes an angular velocity of 2.5 rad on a unit mass,
# so we have to adjust accordingly.
target_impulse = target_angular_velocity / 2.5 * self.vehicle_data.mass
countering_impulse = countering_velocity / 2.5 * self.vehicle_data.mass
# Now just sum those up, and we have the impulse that needs to be
# applied to steer towards target.
impulse = target_impulse + countering_impulse
return impulse
def apply_air_drag(self):
drag_force = self.sensors[LOCAL_DRAG_FORCE]
global_drag_force = base.render.get_relative_vector(
self.vehicle,
drag_force,
)
if not isnan(global_drag_force.x):
self.physics_node.apply_central_impulse(
global_drag_force * globalClock.dt, )
def apply_repulsors(self):
dt = globalClock.dt
repulsor_data = zip(self.vehicle_data.repulsor_nodes,
self.sensors[REPULSOR_DATA],
self.commands[REPULSOR_ACTIVATION],
self.commands[REPULSOR_TARGET_ORIENTATIONS])
for node, data, activation, angle in repulsor_data:
active = data.active
frac = data.fraction
# Repulse in current orientation
if active and activation:
if activation > 1.0:
activation = 1.0
if activation < 0.0:
activation = 0.0
# Repulsor power at zero distance
base_strength = node.get_python_tag(FORCE)
# Effective fraction of repulsors force
transfer_frac = cos(0.5 * pi * frac)
# Effective repulsor force
strength = base_strength * activation * transfer_frac
# Resulting impulse
impulse_dir = Vec3(0, 0, 1)
impulse_dir_world = self.app.render.get_relative_vector(
node,
impulse_dir,
)
impulse = impulse_dir_world * strength
# Apply
repulsor_pos = node.get_pos(self.vehicle)
# FIXME! The position at which an impulse is applied seems to be
# centered around node it is applied to, but offset in the world
# orientation. So, right distance, wrong angle. This is likely a
# bug in Panda3D's Bullet wrapper. Or an idiosyncracy of Bullet.
self.physics_node.apply_impulse(
impulse * dt,
self.app.render.get_relative_vector(
self.vehicle,
repulsor_pos,
),
)
# Contact visualization node
max_distance = node.get_python_tag(ACTIVATION_DISTANCE)
contact_distance = -impulse_dir_world * max_distance * frac
contact_node = node.get_python_tag('ray_end')
contact_node.set_pos(
node.get_pos(self.app.render) + contact_distance, )
#contact_node.set_hpr(node, 0, -90, 0) # Look towards repulsor
#contact_node.set_hpr(0, -90, 0) # Look up
contact_node.set_hpr(0, -90,
contact_node.getR() +
4) # Look up and rotate
contact_node.set_scale(1 - frac)
contact_node.show()
# Sound
sound = node.get_python_tag(REPULSOR_SOUND)
sound.set_volume(activation * 20)
sound.set_play_rate((1 + activation / 2) * 2)
else:
node.get_python_tag('ray_end').hide()
sound = node.get_python_tag(REPULSOR_SOUND)
sound.set_volume(0.0)
sound.set_play_rate(0.0)
# Reorient
old_hpr = node.get_python_tag(REPULSOR_OLD_ORIENTATION)
want_hpr = VBase3(angle.z, angle.x, angle.y)
delta_hpr = want_hpr - old_hpr
max_angle = node.get_python_tag(REPULSOR_TURNING_ANGLE) * dt
if delta_hpr.length() > max_angle:
delta_hpr = delta_hpr / delta_hpr.length() * max_angle
new_hpr = old_hpr + delta_hpr
node.set_hpr(new_hpr)
node.set_python_tag(REPULSOR_OLD_ORIENTATION, new_hpr)
def apply_gyroscope(self):
impulse = self.commands[GYRO_ROTATION]
# Clamp the impulse to what the "motor" can produce.
max_impulse = self.vehicle_data.max_gyro_torque
if impulse.length() > max_impulse:
clamped_impulse = impulse / impulse.length() * max_impulse
else:
clamped_impulse = impulse
self.physics_node.apply_torque_impulse(clamped_impulse)
impulse_ratio = clamped_impulse.length() / max_impulse
sound = self.model.get_python_tag(GYROSCOPE_SOUND)
sound.set_volume(0.5 * impulse_ratio)
sound.set_play_rate(0.9 + 0.1 * impulse_ratio)
def apply_thrusters(self):
dt = globalClock.dt
thruster_data = zip(
self.vehicle_data.thruster_nodes,
self.commands[THRUSTER_ACTIVATION],
)
for node, thrust in thruster_data:
if self.thruster_heat >= 1.0:
thrust = 0.0
current_power = node.get_python_tag(THRUSTER_POWER)
# Adjust thrust to be within bounds of thruster's ability to adjust
# thrust.
ramp_time = node.get_python_tag(THRUSTER_RAMP_TIME)
ramp_step = (1 / ramp_time) * globalClock.dt
thrust = adjust_within_limit(thrust, current_power, ramp_step)
node.set_python_tag(THRUSTER_POWER, thrust)
max_force = node.get_python_tag(FORCE)
real_force = max_force * thrust
# FIXME: See repulsors above for the shortcoming that this suffers
thruster_pos = base.render.get_relative_vector(
self.vehicle,
node.get_pos(self.vehicle),
)
thrust_direction = self.app.render.get_relative_vector(
node, Vec3(0, 0, 1))
self.physics_node.apply_impulse(
thrust_direction * real_force * dt,
thruster_pos,
)
heating = node.get_python_tag(THRUSTER_HEATING)
cooling = node.get_python_tag(THRUSTER_COOLING)
effective_heating = -cooling + (heating - cooling) * thrust
self.thruster_heat += effective_heating * dt
if self.thruster_heat < 0.0:
self.thruster_heat = 0.0
# Sound
sound = node.get_python_tag(THRUSTER_SOUND)
sound.set_volume(thrust * 5)
sound.set_play_rate((1 + thrust / 20) / 3)
was_overheated = node.get_python_tag(THRUSTER_OVERHEATED)
is_overheated = self.thruster_heat > 1.0
if is_overheated and not was_overheated:
sound = node.get_python_tag(THRUSTER_OVERHEAT_SOUND)
sound.set_volume(5)
sound.play()
node.set_python_tag(THRUSTER_OVERHEATED, True)
if not is_overheated:
node.set_python_tag(THRUSTER_OVERHEATED, False)
def apply_airbrake(self):
# Animation and state update only, since the effect is in air drag
dt = globalClock.dt
target = self.commands[AIRBRAKE]
max_movement = self.airbrake_speed * dt
# Clamp change to available speed
delta = target - self.airbrake_state
if abs(delta) > max_movement:
self.airbrake_state += copysign(max_movement, delta)
else:
self.airbrake_state = target
if self.airbrake_state > 1.0:
self.airbrake_state = 1.0
if self.airbrake_state < 0.0:
self.airbrake_state = 0.0
#self.model.pose(AIRBRAKE, self.airbrake_state, partName=AIRBRAKE)
self.model.pose(AIRBRAKE, self.airbrake_state)
def apply_stabilizer_fins(self):
# Animation and state update only, since the effect is in air drag
dt = globalClock.dt
target = self.commands[STABILIZER_FINS]
max_movement = self.stabilizer_fins_speed * dt
# Clamp change to available speed
delta = target - self.stabilizer_fins_state
if abs(delta) > max_movement:
self.stabilizer_fins_state += copysign(max_movement, delta)
else:
self.stabilizer_fins_state = target
if self.stabilizer_fins_state > 1.0:
self.stabilizer_fins_state = 1.0
if self.stabilizer_fins_state < 0.0:
self.stabilizer_fins_state = 0.0
self.model.pose(
STABILIZER_FINS,
self.stabilizer_fins_state,
#partName=STABILIZER_FINS,
)
# FIXME: Implement stabilizing effect
def shock(self, x=0, y=0, z=0):
self.physics_node.apply_impulse(
Vec3(0, 0, 0),
Vec3(random(), random(), random()) * 10,
)
self.physics_node.apply_torque_impulse(Vec3(x, y, z))
dt = globalClock.getDt()
physics.doPhysics(dt)
return task.cont
s.taskMgr.add(step_physics, 'physics simulation')
# A physical object in the simulation
node = BulletRigidBodyNode('Box')
node.setMass(1.0)
node.addShape(BulletSphereShape(1))
# Attaching the physical object in the scene graph and adding
# a visible model to it
np = s.render.attachNewNode(node)
np.set_pos(0, 0, 0)
np.set_hpr(45, 0, 45)
m = loader.loadModel("models/smiley")
m.reparentTo(np)
physics.attachRigidBody(node)
# Let's actually see what's happening
base.cam.setPos(0, -10, 0)
base.cam.lookAt(0, 0, 0)
# Give the object a nudge and run the program
# the impulse vector is in world space, the position at which it is
# applied is in object space.
node.apply_impulse(Vec3(0, 0, 1), Point3(1, 0, 0))
node.apply_impulse(Vec3(0, 0, -1), Point3(-1, 0, 0))
s.run()
