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# MDLLightProbeIrradianceDataSource

Adopt this protocol to provide information for use in automatic placement of light probes around a scene.

```
protocol MDLLightProbeIrradianceDataSource : NSObjectProtocol
```

## Overview

The [`MDLAsset`](/documentation/ModelIO/MDLAsset) [`placeLightProbes(withDensity:heuristic:using:)`](/documentation/ModelIO/MDLAsset/placeLightProbes(withDensity:heuristic:using:)) method automatically creates [`MDLLightProbe`](/documentation/ModelIO/MDLLightProbe) objects, setting their positions and lighting parameters to provide optimal light probe coverage within a scene you define. When you use that method, you must provide an object implementing this protocol, which Model I/O queries in order to evaluate your scene.

## Topics

### Providing Light Probe Information

[`boundingBox`](/documentation/ModelIO/MDLLightProbeIrradianceDataSource/boundingBox)

The bounding region of the scene to which light probes are being added.

[`sphericalHarmonicsLevel`](/documentation/ModelIO/MDLLightProbeIrradianceDataSource/sphericalHarmonicsLevel)

The number of levels of spherical harmonics information provided by the data source.

[`sphericalHarmonicsCoefficients(atPosition:)`](/documentation/ModelIO/MDLLightProbeIrradianceDataSource/sphericalHarmonicsCoefficients(atPosition:))

Asks the data source to provide spherical harmonics coefficients that describe lighting conditions in all directions from the specified point in a scene.


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