yg.phys

Classes for 3-dimensional physics. With Bullet physics library under the hood.

class yg.phys.PhysEnv

Represents a physics environment. An instance of this class is mandatory to realize a physics simulation.

constructor

yg.phys.PhysEnv() -> yg.phys.PhysEnv

function yg.phys.PhysEnv.setGravity()

Sets the gravity vector of the Physics Environment.

yg.phys.PhysEnv.setGravity(x, y, z) -> void

Argument	Type	Info
`x`	number	X-component of the gravity vector [m/s^2]
`y`	number	Y-component of the gravity vector [m/s^2]
`z`	number	Z-component of the gravity vector [m/s^2]

function yg.phys.PhysEnv.newBoxShape()

Creates and stores a new Box Shape in the Physics Environment.

yg.phys.PhysEnv.newBoxShape(name, halfX, halfY, halfZ) -> boolean (true on success, false otherwise)

Argument	Type	Info
`name`	string	Name of the new Shape
`halfX`	number	Half extends in X-dimension [m]
`halfY`	number	Half extends in Y-dimension [m]
`halfZ`	number	Half extends in Z-dimension [m]

function yg.phys.PhysEnv.newSphereShape()

Creates and stores a new Sphere Shape in the Physics Environment.

yg.phys.PhysEnv.newSphereShape(name, radius) -> boolean (true on success, false otherwise)

Argument	Type	Info
`name`	string	Name of the new Shape
`radius`	number	Radius [m]

function yg.phys.PhysEnv.newCylinderShape()

Creates and stores a new Cylinder Shape in the Physics Environment.

yg.phys.PhysEnv.newCylinderShape(name, radius, height) -> boolean (true on success, false otherwise)

Argument	Type	Info
`name`	string	Name of the new Shape
`radius`	number	Radius [m]
`height`	number	Height [m]

function yg.phys.PhysEnv.newConeShape()

Creates and stores a new Cone Shape in the Physics Environment.

yg.phys.PhysEnv.newConeShape(name, radius, height) -> boolean (true on success, false otherwise)

Argument	Type	Info
`name`	string	Name of the new Shape
`radius`	number	Radius [m]
`height`	number	Height [m]

function yg.phys.PhysEnv.deleteShape()

Deletes the Shape with name name from the Physics Environment, if present.

yg.phys.PhysEnv.deleteShape(name) -> boolean (true on success, false otherwise)

Argument	Type	Info
`name`	string	Name of the Shape to delete

function yg.phys.PhysEnv.clearShapes()

Deletes all Shapes from the Physics Environment.

yg.phys.PhysEnv.clearShapes() -> number (Number of Shapes that have been deleted)

function yg.phys.PhysEnv.numShapes()

Returns the number of Shapes contained in the Physics Environment.

yg.phys.PhysEnv.numShapes() -> number

function yg.phys.PhysEnv.newRigidBody()

Creates and stores a new Rigid Body in the Physics Environment.

yg.phys.PhysEnv.newRigidBody(name, shapeName, trafo, info) -> boolean (true on success, false otherwise)

Argument	Type	Info
`name`	string	Name of the new Rigid Body
`shapeName`	string	Name of the Shape to apply
`trafo`	yg.math.Trafo	Initial pose
`info`	yg.phys.RigidBodyInfo	Rigid Body Info

function yg.phys.PhysEnv.deleteRigidBody()

Deletes the Rigid Body with name name from the Physics Environment, if present.

yg.phys.PhysEnv.deleteRigidBody(name) -> boolean (true on success, false otherwise)

Argument	Type	Info
`name`	string	Name of the Rigid Body to delete

function yg.phys.PhysEnv.clearRigidBodies()

Deletes all Rigid Bodies from the Physics Environment.

yg.phys.PhysEnv.clearRigidBodies() -> number (Number of Rigid Bodies that have been deleted)

function yg.phys.PhysEnv.numRigidBodies()

Returns the number of Rigid Bodies contained in the Physics Environment.

yg.phys.PhysEnv.numRigidBodies() -> number

function yg.phys.PhysEnv.getRigidBody()

Returns the Rigid Body with name name, if present. Returns nil otherwise.

yg.phys.PhysEnv.getRigidBody(name) -> yg.phys.RigidBody (may return nil)

Argument	Type	Info
`name`	string	Name of the Rigid Body to get

function yg.phys.PhysEnv.getRigidBodiesStartingWith()

Returns an array of Rigid Bodies with names starting with name.

yg.phys.PhysEnv.getRigidBodiesStartingWith(name) -> {yg.phys.RigidBody} (may return empty array)

Argument	Type	Info
`name`	string	Name prefix of the Rigid Bodies to get

function yg.phys.PhysEnv.tick()

Advances (ticks) the Physics Environment by a given time delta.

yg.phys.PhysEnv.tick(dt) -> void

Argument	Type	Info
`dt`	number	Time delta [seconds]

function yg.phys.PhysEnv.getCollisions()

Returns an array of Collision information that happened since last frame.

yg.phys.PhysEnv.getCollisions() -> {yg.phys.Collision} (may return empty array)

function yg.phys.PhysEnv.rayTest()

Casts a ray and tests its collision in the scene.

yg.phys.PhysEnv.rayTest(eyeX, eyeY, eyeZ, targetX, targetY, targetZ) -> yg.phys.RayTestResult

Argument	Type	Info
`eyeX`	number	X-coordinate of ray origin
`eyeY`	number	Y-coordinate of ray origin
`eyeZ`	number	Z-coordinate of ray origin
`targetX`	number	X-coordinate of target point
`targetY`	number	Y-coordinate of target point
`targetZ`	number	Z-coordinate of target point

class yg.phys.RigidBodyInfo

Represents a Rigid Body Info structure to be used for Rigid Body creation, via yg.phys.PhysEnv.newRigidBody().

Example

-- Create RigidBodyInfo instance and set some properties
rbInfo = yg.phys.RigidBodyInfo()
rbInfo.mass = 2.5
rbInfo.friction = 0.5
rbInfo.restitution = 0.5

constructor

yg.phys.RigidBodyInfo() -> yg.phys.RigidBodyInfo

Properties

Property	Type	Default	Info
`mass`	number	1.0	Mass [kg]
`linearDamping`	number	0.0	Linear Damping factor in [0,1]
`angularDamping`	number	0.0	Angular Damping factor in [0,1]
`friction`	number	0.5	Friction in [0,1]
`rollingFriction`	number	0.0	Rolling Friction in [0,1]
`spinningFriction`	number	0.0	Spinning Friction in [0,1]
`restitution`	number	0.0	Restitution in [0,1]
`linearSleepingThreshold`	number	0.8	Linear Sleeping Threshold in [0,1]
`angularSleepingThreshold`	number	1.0	Angular Sleeping Threshold in [0,1]
`kinematic`	boolean	`false`	If `true`, the Rigid Body will be kinematic
`disableDeactivation`	boolean	`false`	if `true`, the Rigid Body will have disabled deactivation

class yg.phys.RigidBody

Represents a Rigid Body.

function yg.phys.RigidBody.getTrafo()

Returns the current pose (Trafo) of the Rigid Body.

yg.phys.RigidBody.getTrafo() -> yg.math.Trafo

function yg.phys.RigidBody.setTrafo()

Sets the Rigid Body to a new pose (Trafo).

yg.phys.RigidBody.setTrafo(trafo) -> void

Argument	Type	Info
`trafo`	yg.math.Trafo	Trafo to set

function yg.phys.RigidBody.setRestitution()

Sets the Restitution of the Rigid Body.

yg.phys.RigidBody.setRestitution(restitution) -> void

Argument	Type	Info
`restitution`	number	Restitution to set in [0,1]

function yg.phys.RigidBody.setFriction()

Sets the Friction of the Rigid Body.

yg.phys.RigidBody.setFriction(friction) -> void

Argument	Type	Info
`friction`	number	Friction to set in [0,1]

function yg.phys.RigidBody.setSleepingThresholds()

Sets the Sleeping Thresholds of the Rigid Body.

yg.phys.RigidBody.setSleepingThresholds(linear, angular) -> void

Argument	Type	Info
`linear`	number	Linear sleeping threshold to set in [0,1]
`angular`	number	Angular sleeping threshold to set in [0,1]

function yg.phys.RigidBody.setLinearFactors()

Sets the Linear Factors of the Rigid Body.

yg.phys.RigidBody.setLinearFactors(x, y, z) -> void

Argument	Type	Info
`x`	number	X-component linear factor to set in [0,1]
`y`	number	Y-component linear factor to set in [0,1]
`z`	number	Z-component linear factor to set in [0,1]

function yg.phys.RigidBody.setAngularFactor()

Sets the Angular Factors of the Rigid Body from a single value which is applied to all axes.

yg.phys.RigidBody.setAngularFactor(angFac) -> void

Argument	Type	Info
`angFac`	number	Angular factor to set in [0,1]

function yg.phys.RigidBody.setAngularFactors()

Sets the Angular Factors of the Rigid Body from individual values for x-,y-,z-components.

yg.phys.RigidBody.setAngularFactors(x, y, z) -> void

Argument	Type	Info
`x`	number	X-component angular factor to set in [0,1]
`y`	number	Y-component angular factor to set in [0,1]
`z`	number	Z-component angular factor to set in [0,1]

function yg.phys.RigidBody.applyCentralForce()

Applies a central force to the Rigid Body. The force F is applied to the Rigid Body for the time delta t of the next simulation step only.

Example: Applying a force F=5N for t=1s changes the velocity of a Rigid Body with mass m=1kg like so (damping etc. ignored):

dV = F  * t  / m
dV = 5N * 1s / 1kg
dV = 5m/s

yg.phys.RigidBody.applyCentralForce(x, y, z) -> void

Argument	Type	Info
`x`	number	X-component central force to apply [N]
`y`	number	Y-component central force to apply [N]
`z`	number	Z-component central force to apply [N]

function yg.phys.RigidBody.applyCentralImpulse()

Applies a central impulse to the Rigid Body. The impulse is immediately applied to the Rigid Body as if a force F was applied for a time t. Unit: [N*s] (newton-second).

Example: Applying an impulse J=5Ns changes the velocity of a Rigid Body with mass m=1kg like so (damping etc. ignored):

dV = J   / m
dV = 5Ns / 1kg
dV = 5m/s

yg.phys.RigidBody.applyCentralImpulse(x, y, z) -> void

Argument	Type	Info
`x`	number	X-component central impulse to apply [N*s]
`y`	number	Y-component central impulse to apply [N*s]
`z`	number	Z-component central impulse to apply [N*s]

Properties

Property	Type	Info
`name`	string	Name of the Rigid Body

class yg.phys.Collision

Represents a Collision between two Rigid Bodies.

class yg.phys.RayTestResult

Represents the result of a ray test.