ConstraintDescription

Remarks

One description for six joints rather than six types, because they overwhelmingly share parameters — two bodies, two anchor points, an axis, a pair of limits, a spring and a motor — and the alternative is six near-identical records plus the dispatch to tell them apart. What each field means for each kind is on the field.

Anchors are in world space. Jolt will take either, and world space is the one an author can reason about: the hinge is where the hinge visibly is, and Jolt converts to body-local at creation using the poses the bodies have at that moment. The consequence is that a constraint must be created after both bodies are where they belong.

Fields and properties (13)

• public ConstraintKind Kind

  Which joint.

• public BodyHandle First

  One of the two bodies.

• public BodyHandle Second

  The other. May be None to pin to the world.

• public Vector3 FirstAnchor

  Where the joint is on the first body, in world space.

• public Vector3 SecondAnchor

  Where the joint is on the second body, in world space.

• public Vector3 Axis

  The axis the joint turns about (hinge, cone) or slides along (slider), in world space.

• public float LimitMinimum

  The lower limit: an angle in radians for a hinge, a distance in metres for a slider or a distance joint. Ignored by the kinds that have no limits.

• public float LimitMaximum

  The upper limit, in the same units as LimitMinimum.

• public float HalfConeAngle

  The half-angle of a cone constraint, in radians.

• public ConstraintSpring Spring

  How the limits are sprung.

• public ConstraintMotor Motor

  Whether the motor is driving, and towards what kind of target.

• public float MotorTarget

  What the motor is driving towards: a velocity in metres or radians a second, or a position in metres or radians, depending on Motor.

• public float MotorMaximum

  The most force or torque the motor may use. Zero means unlimited.

Methods (6)

• public static ConstraintDescription Fixed(BodyHandle first, BodyHandle second, Vector3 anchor)

  Welds two bodies together where they stand.

• public static ConstraintDescription Point(BodyHandle first, BodyHandle second, Vector3 anchor)

  A ball joint.

• public static ConstraintDescription Hinge(BodyHandle first, BodyHandle second, Vector3 anchor, Vector3 axis)

  A hinge, free to turn all the way round.

• public static ConstraintDescription Slider(BodyHandle first, BodyHandle second, Vector3 anchor, Vector3 axis)

  A slider, free along its whole axis.

• public static ConstraintDescription Distance(BodyHandle first, BodyHandle second, Vector3 firstAnchor, Vector3 secondAnchor, float minimum, float maximum)

  A rope: two points held no further apart than a maximum.

• public static ConstraintDescription Cone(BodyHandle first, BodyHandle second, Vector3 anchor, Vector3 twistAxis, float halfConeAngle)

  A cone: the second body's twist axis held within a half-angle of the first's.

Used by (4)

• PhysicsConstraintTestsVixen.Physics.Tests
• PhysicsSceneTestsVixen.Physics.Tests
• PhysicsWorldVixen.Physics
• Vixen_Physics_Constraints_ConstraintDescriptionSerializerVixen.Physics