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  "identifier" : "/documentation/RealityKit/PhysicallyBasedMaterial/anisotropyAngle-swift.property",
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# anisotropyAngle

The angle at which the anisotropic direction of the material is oriented,
influencing the reflection and appearance of surface highlights.

```
var anisotropyAngle: PhysicallyBasedMaterial.AnisotropyAngle { get set }
```

## Discussion

This property controls the scattering angle for anisotropic objects. If
[`anisotropyLevel`](/documentation/RealityKit/PhysicallyBasedMaterial/anisotropyLevel-swift.property) is `0.0`,
this property has no effect. This property takes a value between `0.0 `and `1.0` or a UV-mapped grayscale image specifying angles for
different parts of the entity.` A` value of black (`0.0)` means a
rotation of 0° and a value of white (`1.0)` indicates a rotation of
360°. To determine the
[`anisotropyAngle`](/documentation/RealityKit/PhysicallyBasedMaterial/anisotropyAngle-swift.property) value from an
angle, divide the desired angle in degrees by `360.0` or the desired
angle in radians by pi times 2.

```swift
let angleDegrees = Float(125.0)
let anisotropyAngleFromDegrees = angleDegrees / 360.0

let angleRadians = Float(2.181662) let anisotropyAngleFromRadians =
angleRadians / (Float.pi * Float(2.0))
```

The following example shows how to specify `anisotropyAngle` using
single values for the entire material:

```swift
material.anisotropyAngle = .AnisotropyAngle(floatLiteral: 0.25)
```

This example shows how to specify anisotropy using a UV-mapped image
texture for [`anisotropyLevel`](/documentation/RealityKit/PhysicallyBasedMaterial/anisotropyLevel-swift.property)
and a separate image for
[`anisotropyAngle`](/documentation/RealityKit/PhysicallyBasedMaterial/anisotropyAngle-swift.property):

```swift
if let anisoLevelResource = try? TextureResource.load(named:
"entity_aniso_level") {
    let anisoLevelMap = MaterialParameters.Texture(sheenResource)
    material.anisotropyLevel = .init(texture: anisoLevelMap)
}
if let anisoAngleResource = try? TextureResource.load(named:
"entity_aniso_angle") {
    let anisoAngleMap = MaterialParameters.Texture(anisoAngleResource)
    material.anisotropyAngle = .init(texture: anisoAngleMap)
}
```

---

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