LineJoint (Nape Physics Library)

type: class
extends: Constraint

LineJoint constraining anchor of one body, to a line segment of the other.

The equation for this constraint could be written like:

       0  = [dir.cross(delta)]  = 0
jointMin <= [dor.dot  (delta)] <= jointMax

where:

dir   = body1.localVectorToWorld(direction).unit();
delta = body2.localPointToWorld(anchor2).sub(body1.localPointToWorld(anchor1));

This is a 2 dimensional constraint, and is (when at the limits) solved as a block constraint for better stability. This is however not the most stable of joint when chained and put under stress and is a rather rare case where using a non-stiff joint can actually be more stable than using a stiff one.

When jointMin = jointMax , it would be better to use a PivotJoint nstead with suitable placed anchors.

The line segment is defined implicitly via the anchor1, direction, jointMin and jointMax properties with end points defined in local coordinate system of body1 like:

start = anchor1.add(direction.unit().mul(jointMin))
end   = anchor1.add(direction.unit().mul(jointMax))

The reason for this more general description of a line segment is that one or both of jointMin, jointMax are permitted to be infinite and a line segment defined with a start and end point is not sufficient to describe such lines.

Constructor

Construct a new LineJoint.

Instance Properties hide inherited show inherited

Whether this constraint is active or not.

Anchor point on first Body, defining position on line.

Anchor point on second Body.

First Body in constraint, defining the line segment.

Second Body in constraint.

Whether constraint will break once maxError is reached.

Whether constraint will break once maxForce is reached.

Set of CbTypes for this constraints for callbacks.

Compound this Constraints belong to.

Damping ratio of elastic properties of constraint.

Set to disable debug drawing/

Direction of line on first Body.

Frequency of elastic properties of constraint.

Whether interactions between related Bodys will be ignored.

Whether this constraint is sleeping or not.

Upper bound for constraint.

Lower bound for constraint.

The maximum amount of error this constraint is allowed to use.

The maximum amount of force this constraint is allowed to use.

Whether constraint will be removed when it breaks.

Space this constraint is inside of.

Whether constraint is stiff, or elastic.

Dynamic object for user to store additional data.

Instance Methods hide inherited show inherited

Compute impulse that was applied to the given Body.

Produce copy of constraint.

Return the constraint-space impulse applied in previous step.

Apply given function to all Bodys linked to the constraint.

nape.constraint.LineJoint

Constructor

Instance Properties hide inherited show inherited

var active : Bool = true

var anchor1 : nape.geom.Vec2

var anchor2 : nape.geom.Vec2

var body1 : Null<nape.phys.Body>

var body2 : Null<nape.phys.Body>

var breakUnderError : Bool = false

var breakUnderForce : Bool = false

readonly var cbTypes : nape.callbacks.CbTypeList = [CbType.ANY_CONSTRAINT]

var compound : Null<nape.phys.Compound> = null

var damping : Float = 1

var debugDraw : Bool = true

var direction : nape.geom.Vec2

var frequency : Float = 10

var ignore : Bool = false

readonly var isSleeping : Bool

var jointMax : Float

var jointMin : Float

var maxError : Float = infinity

var maxForce : Float = infinity

var removeOnBreak : Bool = true

var space : Null<nape.space.Space> = null

var stiff : Bool = true

readonly var userData : Dynamic<Dynamic> = {}

Instance Methods hide inherited show inherited

function bodyImpulse(body:nape.phys.Body):nape.geom.Vec3

copy():Constraint

function impulse():nape.geom.MatMN

function visitBodies(lambda:nape.phys.Body -> Void):Void