InteractionTracker.PositionVelocityInPixelsPerSecond Property
Definition
Important
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The velocity currently applied to position.
The PositionVelocityInPixelsPerSecond property represents the current position velocity of InteractionTracker while in Inertia. There are two main use cases for this property: Retrieving the position velocity of InteractionTracker right after an interaction has occurred or reference the most current velocity of InteractionTracker in an ExpressionAnimation.
public:
property float3 PositionVelocityInPixelsPerSecond { float3 get(); };float3 PositionVelocityInPixelsPerSecond();public Vector3 PositionVelocityInPixelsPerSecond { get; }var vector3 = interactionTracker.positionVelocityInPixelsPerSecond;Public ReadOnly Property PositionVelocityInPixelsPerSecond As Vector3Property Value
The velocity currently applied to position.
Examples
// Listen for the InertiaStateEntered event, so we can grab PositionVelocityInPixelsPerSecond value.
public void InertiaStateEntered(InteractionTracker sender, InteractionTrackerInertiaStateEnteredArgs args)
{
// Grab the current velocity of InteractionTracker after interaction occurs out of the args when the event is fired.
Vector3 interactionVelocity = args.PositionVelocityInPixelsPerSecond;}
}
void CustomSpringMotion(float springCoefficient, float dampingCoefficient, float maxPosition)
{
// Create the InertiaModifier that will be a custom motion emulating a spring
InteractionTrackerInertiaMotion modifier = InteractionTrackerInertiaMotion.Create(_compositor);
modifier.Condition = _compositor.CreateExpressionAnimation("this.Target.NaturalRestingPosition.X > maxPosition");
modifier.Condition.SetScalarParameter("maxPosition", maxPosition);
// Utilize the current Velocity of InteractionTracker in the Expression defining the custom spring motion
modifier.Motion = _compositor.CreateExpressionAnimation("(-springStiffnessCoefficient * (this.Target.Position.X – maxPosition)) + (-dampingCoefficient * this.target.PositionVelocityInPixelsPerSecond.X");
modifier.Motion.SetScalarParameter("springStiffnessCoefficient", springCoefficient);
modifier.Motion.SetScalarParameter("dampingCoefficient", dampingCoefficient);
modifier.Motion.SetScalarParameter("maxPosition", maxPosition);
}
Remarks
When accessing the PositionVelocityInPixelsPerSecond property from the InertiaStateEntered event, you will be retrieving a snapshot of the calculated velocity based on the interaction. This event will only fire once after the interaction has occurred.