RealityFoundation · IOS API REFERENCE

SpatialForceFalloff

struct · iOS 18.0+ · SDK 27.1

struct SpatialForceFalloff

A type that modulates the force strength based on the distance of rigid bodies. Forces applied to rigid bodies near the effect's origin have the largest strength and gradually decay to zero when approaching the boundary of ``ForceEffectBounds``. ``SpatialForceFalloff/rate`` controls how fast the force strength decays. Under the hood the rate is an exponent of the normalized distance over the spatial bounds. For example when the rate is 0, the falloff coefficient (i.e. distance raised to the power of 0) is constantly 1, and that implies no decay or falloff the force strength. ```swift let noFalloff = SpatialForceFalloff(bounds: .sphere(radius: 10), rate: 0) ``` As another example, you can set ``rate`` to `1` to decay the force strength linearly. ```swift let linearFalloff = SpatialForceFalloff(bounds: .sphere(radius: 10), rate: 1) ```

Members (7)

get · iOS 18.0+

distanceOffset

TypeScript

get distanceOffset(): number

Swift declaration

var distanceOffset: Double

A distance from the origin where the falloff begins. Use an offset value that is less than ``bounds``.

set · iOS 18.0+

distanceOffset

TypeScript

set distanceOffset(value: number)

Swift declaration

var distanceOffset: Double

A distance from the origin where the falloff begins. Use an offset value that is less than ``bounds``.

get · iOS 18.0+

rate

TypeScript

get rate(): number

Swift declaration

var rate: Double

The spatial falloff / attenuation rate. An exponent that determines how the effect's strength diminishes with distance. Use a non-negative rate. * When the rate is **0**, no falloff occurs. * When the rate is **greater than 0 and less than 1.0**, falloff occurs slower and is sublinear. * When the rate is **1.0**, falloff is linear. * When the rate is **greater than 1**, falloff occurs faster and is nonlinear.

set · iOS 18.0+

rate

TypeScript

set rate(value: number)

Swift declaration

var rate: Double

init · iOS 18.0+

init

TypeScript

static init(bounds: ForceEffectBounds, rate?: number, distanceOffset?: number): SpatialForceFalloff

Swift declaration

init(bounds: ForceEffectBounds, rate: Double = 1.0, distanceOffset: Double = 0)

Creates a spatial force falloff. - Parameters: - bounds: The spatial bounds used to compute the strength falloff. - rate: The rate at which the effect's strength diminishes. - distanceOffset: The offset from the origin where fall begins. * When the rate is **0**, no falloff occurs. (Rigid bodies outside the bounds are culled.) * When the rate is **greater than 0 and less than 1.0**, falloff occurs slower and is sublinear. * When the rate is **1.0**, falloff is linear. * When the rate is **greater than 1**, falloff occurs faster and is nonlinear.

get · iOS 18.0+

bounds

TypeScript

get bounds(): ForceEffectBounds

Swift declaration

var bounds: ForceEffectBounds

The spatial bounds that define the area over which the force effect's strength decreases.

set · iOS 18.0+

bounds

TypeScript

set bounds(value: ForceEffectBounds)

Swift declaration

var bounds: ForceEffectBounds

The spatial bounds that define the area over which the force effect's strength decreases.

Skipped declarations

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