<!--
{
  "availability" : [
    "iOS: 9.0.0 -",
    "iPadOS: 9.0.0 -",
    "macCatalyst: 13.1.0 -",
    "macOS: 10.11.0 -",
    "tvOS: 9.0.0 -",
    "visionOS: 1.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "ModelIO",
  "identifier" : "/documentation/ModelIO/MDLPhysicallyPlausibleLight",
  "metadataVersion" : "0.1.0",
  "role" : "Class",
  "symbol" : {
    "kind" : "Class",
    "modules" : [
      "Model I/O"
    ],
    "preciseIdentifier" : "c:objc(cs)MDLPhysicallyPlausibleLight"
  },
  "title" : "MDLPhysicallyPlausibleLight"
}
-->

# MDLPhysicallyPlausibleLight

A light source for use in shading models based on real-world physics.

```
class MDLPhysicallyPlausibleLight
```

## Topics

### Managing Light Color and Intensity

[`color`](/documentation/ModelIO/MDLPhysicallyPlausibleLight/color)

The color of the light source.

[`lumens`](/documentation/ModelIO/MDLPhysicallyPlausibleLight/lumens)

The total visible intensity of the light source, in lumens.

[`-  setColorByTemperature:`](/documentation/ModelIO/MDLPhysicallyPlausibleLight/setColorByTemperature(_:))

Sets the light’s color based on a black-body temperature.

### Managing Light Geometry

[`innerConeAngle`](/documentation/ModelIO/MDLPhysicallyPlausibleLight/innerConeAngle)

The radial angle, in degrees, of the area fully illuminated by the light.

[`outerConeAngle`](/documentation/ModelIO/MDLPhysicallyPlausibleLight/outerConeAngle)

The radial angle, in degrees, at which the illumination from a spotlight becomes zero.

### Managing Attenuation

[`attenuationStartDistance`](/documentation/ModelIO/MDLPhysicallyPlausibleLight/attenuationStartDistance)

The distance from the light source, in units of local coordinate space, at which its illumination begins to diminish.

[`attenuationEndDistance`](/documentation/ModelIO/MDLPhysicallyPlausibleLight/attenuationEndDistance)

The distance from the light source, in units of local coordinate space, at which its illumination becomes zero.

## Relationships

### Conforms To

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

[`Hashable`](/documentation/Swift/Hashable)

[`MDLNamed`](/documentation/ModelIO/MDLNamed)

[`Equatable`](/documentation/Swift/Equatable)

[`CVarArg`](/documentation/Swift/CVarArg)

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

### Inherited By

[`MDLAreaLight`](/documentation/ModelIO/MDLAreaLight)

[`MDLPhotometricLight`](/documentation/ModelIO/MDLPhotometricLight)

### Inherits From

[`MDLLight`](/documentation/ModelIO/MDLLight)

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)