Defold C

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Defold Lua

Extension

firebase

Version

Bullet constraint API

Creates and controls Bullet constraints between Defold rigid bodies. A constraint belongs to the supplied world and is destroyed automatically with either body, with the world, or when the module is finalized. It is temporarily removed from the native world while either linked body is disabled and is restored when both bodies are enabled again. Dropping its Lua userdata does not destroy the native constraint; call destroy for early release.

Creator positions and all other linear values use Defold units and are converted with physics.scale. Angles are radians. Axes are one-based in Lua: axes 1-3 are linear and axes 4-6 are angular. Mutating functions cannot be called while the physics world is stepping.

CONSTRAINT_TYPE_* values identify the concrete constraint exposed by this binding. This deliberately distinguishes universal, hinge2, and spring 6-DOF constraints even though Bullet 2.77 reports their native base type as 6-DOF.

Version: alpha

FUNCTIONS
bullet3d.constraint.create_cone_twist()	Create a cone-twist constraint
bullet3d.constraint.create_generic_6dof()	Create a generic six-degree-of-freedom constraint
bullet3d.constraint.create_generic_6dof_spring()	Create a generic spring six-degree-of-freedom constraint
bullet3d.constraint.create_hinge()	Create a hinge constraint
bullet3d.constraint.create_hinge2()	Create a hinge2 constraint
bullet3d.constraint.create_point_to_point()	Create a point-to-point constraint
bullet3d.constraint.create_slider()	Create a slider constraint
bullet3d.constraint.create_universal()	Create a universal constraint
bullet3d.constraint.destroy()	Destroy a constraint
bullet3d.constraint.enable_cone_twist_motor()	Enable or disable the cone-twist motor
bullet3d.constraint.enable_spring()	Enable or disable a spring axis
bullet3d.constraint.get_6dof_angle()	Get a current 6-DOF angle
bullet3d.constraint.get_6dof_axis()	Get a current 6-DOF angular axis
bullet3d.constraint.get_6dof_motor()	Get 6-DOF motor settings
bullet3d.constraint.get_6dof_position()	Get a current 6-DOF linear position
bullet3d.constraint.get_anchors()	Get universal or hinge2 anchors
bullet3d.constraint.get_angles()	Get universal or hinge2 angles
bullet3d.constraint.get_axes()	Get universal or hinge2 axes
bullet3d.constraint.get_body_a()	Get the first linked body
bullet3d.constraint.get_body_b()	Get the second linked body
bullet3d.constraint.get_collide_connected()	Get whether connected bodies can collide
bullet3d.constraint.get_cone_twist_limits()	Get cone-twist angular spans
bullet3d.constraint.get_frame_a()	Get local frame A
bullet3d.constraint.get_frame_b()	Get local frame B
bullet3d.constraint.get_hinge_angle()	Get the current hinge angle
bullet3d.constraint.get_hinge_limits()	Get hinge angular limits
bullet3d.constraint.get_hinge_motor()	Get hinge motor settings
bullet3d.constraint.get_limit()	Get a 6-DOF axis limit
bullet3d.constraint.get_pivots()	Get point-to-point pivots
bullet3d.constraint.get_slider_limits()	Get slider limits
bullet3d.constraint.get_slider_motor()	Get slider motor settings
bullet3d.constraint.get_slider_position()	Get the current slider position
bullet3d.constraint.get_twist_angle()	Get the current cone-twist twist angle
bullet3d.constraint.get_type()	Get the constraint type
bullet3d.constraint.get_type_name()	Get the constraint type name
bullet3d.constraint.get_use_linear_reference_frame_a()	Get the slider linear reference-frame choice
bullet3d.constraint.get_world()	Get the owning world
bullet3d.constraint.is_active()	Test whether a constraint is active in its world
bullet3d.constraint.is_angular_only()	Test angular-only mode
bullet3d.constraint.is_limited()	Test whether a 6-DOF axis is limited
bullet3d.constraint.is_past_swing_limit()	Test whether a cone-twist is past its swing limit
bullet3d.constraint.is_valid()	Test whether a constraint handle is valid
bullet3d.constraint.set_6dof_motor()	Set 6-DOF motor settings
bullet3d.constraint.set_angular_only()	Set angular-only mode
bullet3d.constraint.set_cone_twist_limits()	Set cone-twist angular spans
bullet3d.constraint.set_cone_twist_motor_target()	Set the cone-twist motor target
bullet3d.constraint.set_frame_a()	Set local frame A
bullet3d.constraint.set_frame_b()	Set local frame B
bullet3d.constraint.set_hinge_axis()	Set the one-body hinge axis
bullet3d.constraint.set_hinge_limits()	Set hinge angular limits
bullet3d.constraint.set_hinge_motor()	Set hinge motor settings
bullet3d.constraint.set_hinge_motor_target()	Set a hinge motor angle target
bullet3d.constraint.set_limit()	Set a 6-DOF axis limit
bullet3d.constraint.set_pivots()	Set point-to-point pivots
bullet3d.constraint.set_slider_limits()	Set slider limits
bullet3d.constraint.set_slider_motor()	Set slider motor settings
bullet3d.constraint.set_spring_damping()	Set spring damping
bullet3d.constraint.set_spring_equilibrium_point()	Set spring equilibrium points
bullet3d.constraint.set_spring_stiffness()	Set spring stiffness

CONSTANTS
bullet3d.constraint.CONSTRAINT_TYPE_CONE_TWIST	Cone-twist constraint type
bullet3d.constraint.CONSTRAINT_TYPE_GENERIC_6DOF	Generic 6-DOF constraint type
bullet3d.constraint.CONSTRAINT_TYPE_GENERIC_6DOF_SPRING	Generic spring 6-DOF constraint type
bullet3d.constraint.CONSTRAINT_TYPE_HINGE	Hinge constraint type
bullet3d.constraint.CONSTRAINT_TYPE_HINGE2	Hinge2 constraint type
bullet3d.constraint.CONSTRAINT_TYPE_POINT_TO_POINT	Point-to-point constraint type
bullet3d.constraint.CONSTRAINT_TYPE_SLIDER	Slider constraint type
bullet3d.constraint.CONSTRAINT_TYPE_UNIVERSAL	Universal constraint type

Functions

bullet3d.constraint.create_cone_twist()

bullet3d.constraint.create_cone_twist(body_a,body_b,params)

The params table uses the same local-frame fields as a hinge and optionally accepts angular_only and collide_connected. The world is derived from body_a.

PARAMETERS

`body_a`	`btRigidBody`	first body
`body_b`	`btRigidBody` `nil`	second body or world
`params`	`table`	local frames and options

RETURNS

constraint btTypedConstraint cone-twist constraint

bullet3d.constraint.create_generic_6dof()

bullet3d.constraint.create_generic_6dof(body_a,body_b,params)

The params table requires local frame A and, for a two-body constraint, local frame B. It optionally accepts collide_connected. The world is derived from body_a. Bullet 2.77's active 6-DOF solver ignores its legacy linear-reference-frame selector, so that field is rejected rather than silently accepted.

PARAMETERS

`body_a`	`btRigidBody`	first body
`body_b`	`btRigidBody` `nil`	second body or world
`params`	`table`	local frames and options

RETURNS

constraint btTypedConstraint generic 6-DOF constraint

bullet3d.constraint.create_generic_6dof_spring()

bullet3d.constraint.create_generic_6dof_spring(body_a,body_b,params)

Both bodies and both local frames are required. The params table optionally accepts collide_connected. The world is derived from body_a. Bullet 2.77's active spring 6-DOF solver ignores its legacy linear-reference-frame selector, so that field is rejected rather than silently accepted.

PARAMETERS

`body_a`	`btRigidBody`	first body
`body_b`	`btRigidBody`	second body
`params`	`table`	local frames and options

RETURNS

constraint btTypedConstraint spring 6-DOF constraint

EXAMPLES

Create a spring that moves along its first linear axis:

function init(self)
    local body_a = bullet3d.get_rigid_body("/body_a#collisionobject")
    local body_b = bullet3d.get_rigid_body("/body_b#collisionobject")
    self.spring = bullet3d.constraint.create_generic_6dof_spring(body_a, body_b, {
        frame_a_position = vmath.vector3(),
        frame_a_rotation = vmath.quat(),
        frame_b_position = vmath.vector3(),
        frame_b_rotation = vmath.quat(),
    })
    bullet3d.constraint.set_limit(self.spring, 1, -1, 1)
    bullet3d.constraint.enable_spring(self.spring, 1, true)
    bullet3d.constraint.set_spring_stiffness(self.spring, 1, 20)
    bullet3d.constraint.set_spring_damping(self.spring, 1, 0.5)
    bullet3d.constraint.set_spring_equilibrium_point(self.spring, 1, 0)
end

function final(self)
    if self.spring and bullet3d.constraint.is_valid(self.spring) then
        bullet3d.constraint.destroy(self.spring)
    end
end

bullet3d.constraint.create_hinge()

bullet3d.constraint.create_hinge(body_a,body_b,params)

The params table requires frame_a_position and frame_a_rotation, plus the corresponding frame B fields for a two-body constraint. It optionally accepts use_reference_frame_a, angular_only, and collide_connected. The world is derived from body_a.

PARAMETERS

`body_a`	`btRigidBody`	first body
`body_b`	`btRigidBody` `nil`	second body or world
`params`	`table`	local frames and options

RETURNS

constraint btTypedConstraint hinge constraint

EXAMPLES

Create a motorized hinge with a 90-degree range:

function init(self)
    local body_a = bullet3d.get_rigid_body("/door#collisionobject")
    local body_b = bullet3d.get_rigid_body("/frame#collisionobject")
    self.hinge = bullet3d.constraint.create_hinge(body_a, body_b, {
        frame_a_position = vmath.vector3(-0.5, 0, 0),
        frame_a_rotation = vmath.quat(),
        frame_b_position = vmath.vector3(0.5, 0, 0),
        frame_b_rotation = vmath.quat(),
    })
    bullet3d.constraint.set_hinge_limits(self.hinge, -math.pi / 4, math.pi / 4)
    bullet3d.constraint.set_hinge_motor(self.hinge, true, 1.5, 2.5)
end

function final(self)
    if self.hinge and bullet3d.constraint.is_valid(self.hinge) then
        bullet3d.constraint.destroy(self.hinge)
    end
end

bullet3d.constraint.create_hinge2()

bullet3d.constraint.create_hinge2(body_a,body_b,params)

Both bodies are required. The params table requires a world-space anchor and non-zero, orthogonal axis1 and axis2 vectors. Its initial linear suspension travel is one Defold unit in either direction. It optionally accepts collide_connected. The world is derived from body_a.

PARAMETERS

`body_a`	`btRigidBody`	first body
`body_b`	`btRigidBody`	second body
`params`	`table`	anchor, axes, and options

RETURNS

constraint btTypedConstraint hinge2 constraint

bullet3d.constraint.create_point_to_point()

bullet3d.constraint.create_point_to_point(body_a,body_b,params)

params.pivot_a is required. params.pivot_b is required with body_b; for a one-body constraint it is an optional world-space anchor. The params table also accepts collide_connected, which defaults to false. The world is derived from body_a; both bodies must belong to that same world.

PARAMETERS

`body_a`	`btRigidBody`	first body
`body_b`	`btRigidBody` `nil`	second body or world
`params`	`table`	pivots and options

RETURNS

constraint btTypedConstraint point-to-point constraint

EXAMPLES

Join two bodies at matching local pivots and explicitly destroy the constraint when the script is finalized:

function init(self)
    local body_a = bullet3d.get_rigid_body("/body_a#collisionobject")
    local body_b = bullet3d.get_rigid_body("/body_b#collisionobject")
    self.constraint = bullet3d.constraint.create_point_to_point(body_a, body_b, {
        pivot_a = vmath.vector3(0.5, 0, 0),
        pivot_b = vmath.vector3(-0.5, 0, 0),
    })
end

function final(self)
    if self.constraint and bullet3d.constraint.is_valid(self.constraint) then
        bullet3d.constraint.destroy(self.constraint)
    end
end

bullet3d.constraint.create_slider()

bullet3d.constraint.create_slider(body_a,body_b,params)

The params table requires local frame A and, for a two-body constraint, local frame B. It optionally accepts use_linear_reference_frame_a and collide_connected. The world is derived from body_a.

PARAMETERS

`body_a`	`btRigidBody`	first body
`body_b`	`btRigidBody` `nil`	second body or world
`params`	`table`	local frames and options

RETURNS

constraint btTypedConstraint slider constraint

bullet3d.constraint.create_universal()

bullet3d.constraint.create_universal(body_a,body_b,params)

Both bodies are required. The params table requires a world-space anchor and non-zero, orthogonal axis1 and axis2 vectors. It optionally accepts collide_connected. The world is derived from body_a.

PARAMETERS

`body_a`	`btRigidBody`	first body
`body_b`	`btRigidBody`	second body
`params`	`table`	anchor, axes, and options

RETURNS

constraint btTypedConstraint universal constraint

bullet3d.constraint.destroy()

bullet3d.constraint.destroy(constraint)

Destroy a constraint

PARAMETERS

constraint btTypedConstraint constraint

bullet3d.constraint.enable_cone_twist_motor()

bullet3d.constraint.enable_cone_twist_motor(constraint,enabled)

Enable or disable the cone-twist motor

PARAMETERS

`constraint`	`btTypedConstraint`	cone-twist constraint
`enabled`	`boolean`	motor state

bullet3d.constraint.enable_spring()

bullet3d.constraint.enable_spring(constraint,axis,enabled)

Enable or disable a spring axis

PARAMETERS

`constraint`	`btTypedConstraint`	spring 6-DOF or hinge2 constraint
`axis`	`number`	one-based axis from 1 to 6
`enabled`	`boolean`	spring state

bullet3d.constraint.get_6dof_angle()

bullet3d.constraint.get_6dof_angle(constraint,axis)

Get a current 6-DOF angle

PARAMETERS

`constraint`	`btTypedConstraint`	6-DOF-derived constraint
`axis`	`number`	one-based angular-axis index from 1 to 3

RETURNS

angle number current angle in radians

bullet3d.constraint.get_6dof_axis()

bullet3d.constraint.get_6dof_axis(constraint,axis)

Get a current 6-DOF angular axis

PARAMETERS

`constraint`	`btTypedConstraint`	6-DOF-derived constraint
`axis`	`number`	one-based angular-axis index from 1 to 3

RETURNS

direction vector3 world-space unit axis

bullet3d.constraint.get_6dof_motor()

bullet3d.constraint.get_6dof_motor(constraint,axis)

Axes 1-3 are linear and axes 4-6 are angular. Bounce is zero for linear motors because Bullet only implements it for angular motors.

PARAMETERS

`constraint`	`btTypedConstraint`	6-DOF-derived constraint
`axis`	`number`	one-based axis from 1 to 6

RETURNS

`enabled`	`boolean`	motor state
`target_velocity`	`number`	target velocity
`max_impulse`	`number`	maximum motor impulse
`bounce`	`number`	angular bounce from 0 to 1

bullet3d.constraint.get_6dof_position()

bullet3d.constraint.get_6dof_position(constraint,axis)

Get a current 6-DOF linear position

PARAMETERS

`constraint`	`btTypedConstraint`	6-DOF-derived constraint
`axis`	`number`	one-based linear-axis index from 1 to 3

RETURNS

position number relative position in Defold units

bullet3d.constraint.get_anchors()

bullet3d.constraint.get_anchors(constraint)

Get universal or hinge2 anchors

PARAMETERS

constraint btTypedConstraint universal or hinge2 constraint

RETURNS

`anchor_a`	`vector3`	world-space anchor on body A
`anchor_b`	`vector3`	world-space anchor on body B

bullet3d.constraint.get_angles()

bullet3d.constraint.get_angles(constraint)

Get universal or hinge2 angles

PARAMETERS

constraint btTypedConstraint universal or hinge2 constraint

RETURNS

`angle_1`	`number`	first angle in radians
`angle_2`	`number`	second angle in radians

bullet3d.constraint.get_axes()

bullet3d.constraint.get_axes(constraint)

Get universal or hinge2 axes

PARAMETERS

constraint btTypedConstraint universal or hinge2 constraint

RETURNS

`axis_1`	`vector3`	first world-space unit axis
`axis_2`	`vector3`	second world-space unit axis

bullet3d.constraint.get_body_a()

bullet3d.constraint.get_body_a(constraint)

Get the first linked body

PARAMETERS

constraint btTypedConstraint constraint

RETURNS

body btRigidBody first body

bullet3d.constraint.get_body_b()

bullet3d.constraint.get_body_b(constraint)

Get the second linked body

PARAMETERS

constraint btTypedConstraint constraint

RETURNS

body btRigidBody
nil second body, or nil for a world constraint

bullet3d.constraint.get_collide_connected()

bullet3d.constraint.get_collide_connected(constraint)

Get whether connected bodies can collide

PARAMETERS

constraint btTypedConstraint constraint

RETURNS

collide boolean whether connected bodies can collide

bullet3d.constraint.get_cone_twist_limits()

bullet3d.constraint.get_cone_twist_limits(constraint)

Get cone-twist angular spans

PARAMETERS

constraint btTypedConstraint cone-twist constraint

RETURNS

`swing_span_1`	`number`	first swing span in radians
`swing_span_2`	`number`	second swing span in radians
`twist_span`	`number`	twist span in radians

bullet3d.constraint.get_frame_a()

bullet3d.constraint.get_frame_a(constraint)

Returns position and rotation. For one-body generic 6-DOF and slider constraints this is the user-body frame, despite Bullet storing it as its native frame B.

PARAMETERS

constraint btTypedConstraint framed constraint

RETURNS

`position`	`vector3`	local position
`rotation`	`quaternion`	local rotation

bullet3d.constraint.get_frame_b()

bullet3d.constraint.get_frame_b(constraint)

Get local frame B

PARAMETERS

constraint btTypedConstraint framed constraint

RETURNS

`position`	`vector3`	local position or world frame position
`rotation`	`quaternion`	local rotation or world frame rotation

bullet3d.constraint.get_hinge_angle()

bullet3d.constraint.get_hinge_angle(constraint)

Get the current hinge angle

PARAMETERS

constraint btTypedConstraint hinge constraint

RETURNS

angle number angle in radians

bullet3d.constraint.get_hinge_limits()

bullet3d.constraint.get_hinge_limits(constraint)

Get hinge angular limits

PARAMETERS

constraint btTypedConstraint hinge constraint

RETURNS

`lower`	`number`	lower angle in radians
`upper`	`number`	upper angle in radians

bullet3d.constraint.get_hinge_motor()

bullet3d.constraint.get_hinge_motor(constraint)

Get hinge motor settings

PARAMETERS

constraint btTypedConstraint hinge constraint

RETURNS

`enabled`	`boolean`	motor state
`target_velocity`	`number`	angular target velocity
`max_impulse`	`number`	maximum angular motor impulse

bullet3d.constraint.get_limit()

bullet3d.constraint.get_limit(constraint,axis)

Axes 1-3 return linear limits in Defold units. Axes 4-6 return angular limits in radians.

PARAMETERS

`constraint`	`btTypedConstraint`	6-DOF-derived constraint
`axis`	`number`	one-based axis from 1 to 6

RETURNS

`lower`	`number`	lower limit
`upper`	`number`	upper limit

bullet3d.constraint.get_pivots()

bullet3d.constraint.get_pivots(constraint)

Get point-to-point pivots

PARAMETERS

constraint btTypedConstraint point-to-point constraint

RETURNS

`pivot_a`	`vector3`	local body-A pivot
`pivot_b`	`vector3`	local body-B pivot or world anchor

bullet3d.constraint.get_slider_limits()

bullet3d.constraint.get_slider_limits(constraint)

Get slider limits

PARAMETERS

constraint btTypedConstraint slider constraint

RETURNS

`lower_linear`	`number`	lower linear limit in Defold units
`upper_linear`	`number`	upper linear limit in Defold units
`lower_angular`	`number`	lower angular limit in radians
`upper_angular`	`number`	upper angular limit in radians

bullet3d.constraint.get_slider_motor()

bullet3d.constraint.get_slider_motor(constraint,motor)

Get slider motor settings

PARAMETERS

`constraint`	`btTypedConstraint`	slider constraint
`motor`	`string`	`linear` or `angular`

RETURNS

`enabled`	`boolean`	motor state
`target_velocity`	`number`	target velocity
`max_force`	`number`	maximum motor force

bullet3d.constraint.is_valid()

bullet3d.constraint.is_valid(constraint)

Test whether a constraint handle is valid

PARAMETERS

constraint btTypedConstraint constraint handle

RETURNS

valid boolean true while the native constraint exists

bullet3d.constraint.set_6dof_motor()

bullet3d.constraint.set_6dof_motor(constraint,axis,enabled,target_velocity,max_impulse,bounce)

Set 6-DOF motor settings

PARAMETERS

`constraint`	`btTypedConstraint`	6-DOF-derived constraint
`axis`	`number`	one-based axis from 1 to 6
`enabled`	`boolean`	motor state
`target_velocity`	`number`	target velocity
`max_impulse`	`number`	non-negative maximum motor impulse
`bounce`	`number` `nil`	optional angular bounce from 0 to 1

bullet3d.constraint.set_angular_only()

bullet3d.constraint.set_angular_only(constraint,angular_only)

Set angular-only mode

PARAMETERS

`constraint`	`btTypedConstraint`	hinge or cone-twist constraint
`angular_only`	`boolean`	angular-only state

bullet3d.constraint.set_cone_twist_limits()

bullet3d.constraint.set_cone_twist_limits(constraint,swing_span_1,swing_span_2,twist_span,softness,bias,relaxation)

Set cone-twist angular spans

PARAMETERS

`constraint`	`btTypedConstraint`	cone-twist constraint
`swing_span_1`	`number`	non-negative first swing span
`swing_span_2`	`number`	non-negative second swing span
`twist_span`	`number`	non-negative twist span
`softness`	`number` `nil`	optional softness from 0 to 1
`bias`	`number` `nil`	optional bias from 0 to 1
`relaxation`	`number` `nil`	optional relaxation from 0 to 1

bullet3d.constraint.set_cone_twist_motor_target()

bullet3d.constraint.set_cone_twist_motor_target(constraint,target,constraint_space)

Set the cone-twist motor target

PARAMETERS

`constraint`	`btTypedConstraint`	cone-twist constraint
`target`	`quaternion`	target orientation
`constraint_space`	`boolean` `nil`	target is already in constraint space

bullet3d.constraint.set_frame_a()

bullet3d.constraint.set_frame_a(constraint,position,rotation)

Set local frame A

PARAMETERS

`constraint`	`btTypedConstraint`	mutable framed constraint
`position`	`vector3`	local position
`rotation`	`quaternion`	local rotation

bullet3d.constraint.set_frame_b()

bullet3d.constraint.set_frame_b(constraint,position,rotation)

Set local frame B

PARAMETERS

`constraint`	`btTypedConstraint`	mutable framed constraint
`position`	`vector3`	local position or world frame position
`rotation`	`quaternion`	local rotation or world frame rotation

bullet3d.constraint.set_hinge_axis()

bullet3d.constraint.set_hinge_axis(constraint,axis)

This function only supports hinges attached to the world. For a two-body hinge, change both local frames with set_frame_a and set_frame_b.

PARAMETERS

`constraint`	`btTypedConstraint`	one-body hinge constraint
`axis`	`vector3`	non-zero axis in body-A space

bullet3d.constraint.set_hinge_limits()

bullet3d.constraint.set_hinge_limits(constraint,lower,upper,bias,relaxation)

Set hinge angular limits

PARAMETERS

`constraint`	`btTypedConstraint`	hinge constraint
`lower`	`number`	lower angle in radians
`upper`	`number`	upper angle in radians
`bias`	`number` `nil`	optional limit bias from 0 to 1
`relaxation`	`number` `nil`	optional relaxation from 0 to 1

bullet3d.constraint.set_hinge_motor()

bullet3d.constraint.set_hinge_motor(constraint,enabled,target_velocity,max_impulse)

Set hinge motor settings

PARAMETERS

`constraint`	`btTypedConstraint`	hinge constraint
`enabled`	`boolean`	motor state
`target_velocity`	`number`	angular target velocity
`max_impulse`	`number`	non-negative maximum angular motor impulse

bullet3d.constraint.set_hinge_motor_target()

bullet3d.constraint.set_hinge_motor_target(constraint,target_angle,time_step)

Set a hinge motor angle target

PARAMETERS

`constraint`	`btTypedConstraint`	hinge constraint
`target_angle`	`number`	target angle in radians
`time_step`	`number`	positive step duration in seconds

bullet3d.constraint.set_limit()

bullet3d.constraint.set_limit(constraint,axis,lower,upper)

Set a 6-DOF axis limit

PARAMETERS

`constraint`	`btTypedConstraint`	6-DOF-derived constraint
`axis`	`number`	one-based axis from 1 to 6
`lower`	`number`	lower limit
`upper`	`number`	upper limit

bullet3d.constraint.set_pivots()

bullet3d.constraint.set_pivots(constraint,pivot_a,pivot_b)

Set point-to-point pivots

PARAMETERS

`constraint`	`btTypedConstraint`	point-to-point constraint
`pivot_a`	`vector3`	local body-A pivot
`pivot_b`	`vector3`	local body-B pivot or world anchor

bullet3d.constraint.set_slider_limits()

bullet3d.constraint.set_slider_limits(constraint,lower_linear,upper_linear,lower_angular,upper_angular)

Set slider limits

PARAMETERS

`constraint`	`btTypedConstraint`	slider constraint
`lower_linear`	`number`	lower linear limit in Defold units
`upper_linear`	`number`	upper linear limit in Defold units
`lower_angular`	`number`	lower angular limit in radians
`upper_angular`	`number`	upper angular limit in radians

bullet3d.constraint.set_slider_motor()

bullet3d.constraint.set_slider_motor(constraint,motor,enabled,target_velocity,max_force)

Set slider motor settings

PARAMETERS

`constraint`	`btTypedConstraint`	slider constraint
`motor`	`string`	`linear` or `angular`
`enabled`	`boolean`	motor state
`target_velocity`	`number`	target velocity
`max_force`	`number`	non-negative maximum motor force

bullet3d.constraint.set_spring_damping()

bullet3d.constraint.set_spring_damping(constraint,axis,damping)

Set spring damping

PARAMETERS

`constraint`	`btTypedConstraint`	spring 6-DOF or hinge2 constraint
`axis`	`number`	one-based axis from 1 to 6
`damping`	`number`	damping from 0 to 1

bullet3d.constraint.set_spring_equilibrium_point()

bullet3d.constraint.set_spring_equilibrium_point(constraint,axis,value)

With no axis, captures all current transforms. With an axis and no value, captures that axis. Linear values use Defold units and angular values use radians.

PARAMETERS

`constraint`	`btTypedConstraint`	spring 6-DOF or hinge2 constraint
`axis`	`number` `nil`	optional one-based axis from 1 to 6
`value`	`number` `nil`	optional explicit equilibrium value

bullet3d.constraint.set_spring_stiffness()

bullet3d.constraint.set_spring_stiffness(constraint,axis,stiffness)

Stiffness is Bullet's solver tuning coefficient, not a force or torque value, and is therefore independent of physics.scale for every axis.

PARAMETERS

`constraint`	`btTypedConstraint`	spring 6-DOF or hinge2 constraint
`axis`	`number`	one-based axis from 1 to 6
`stiffness`	`number`	non-negative stiffness

Bullet constraint API

Functions

Constants