# CalculateInterpolatedLightAndOcclusionProbes

> Calculate light probes and occlusion probes at the given world space positions.

## Definition

* **Type:** Method
* **Namespace:** [UnityEngine](/engine/6000.6/script-reference/unityengine.md)
* **Assembly:** UnityEngine.CoreModule

## CalculateInterpolatedLightAndOcclusionProbes(Vector3\[], SphericalHarmonicsL2\[], Vector4\[])

Calculate light probes and occlusion probes at the given world space positions.

```csharp
public static void CalculateInterpolatedLightAndOcclusionProbes(Vector3[] positions, SphericalHarmonicsL2[] lightProbes, Vector4[] occlusionProbes)
```

### Parameters

**** (\[Vector3\[]]\(/engine/6000.6/script-reference/unityengine/vector3)): The array of world space positions used to evaluate the probes.**** (\[SphericalHarmonicsL2\[]]\(/engine/6000.6/script-reference/unityengine/rendering/sphericalharmonicsl2)): The array where the resulting light probes are written to.**** (\[Vector4\[]]\(/engine/6000.6/script-reference/unityengine/vector4)): The array where the resulting occlusion probes are written to.

### Remarks

If there are no probes baked in the Scene, the ambient probe will be written to the `lightProbes` array and `Vector4` (1,1,1,1) will be written to the `occlusionProbes` array.

ArgumentNullException is thrown if `positions` is `null`.

You can omit either `lightProbes` or `occlusionProbes` array by passing `null` to the function, but you cannot omit both at the same time. If both arrays are omitted, an ArgumentException is thrown. `lightProbes` and `occlusionProbes` should be calculated together for better performance.

For the overload which takes arrays as arguments, the `lightProbes` and `occlusionProbes` must have at least the same number of elements as the `positions` array.

For the overload which takes lists as arguments, the output lists will be resized to fit the size of the `positions` array if there is not enough space in the given lists.

The returned probes may be further used for instanced rendering by copying them to a MaterialPropertyBlock object via [MaterialPropertyBlock.CopySHCoefficientArraysFrom](/engine/6000.6/script-reference/unityengine/materialpropertyblock/copyshcoefficientarraysfrom.md) and [MaterialPropertyBlock.CopyProbeOcclusionArrayFrom](/engine/6000.6/script-reference/unityengine/materialpropertyblock/copyprobeocclusionarrayfrom.md).

```csharp
using UnityEngine;

// This script uses OnPreCull for the rendering. It is mandatory to put the script to a Camera object.
// Make sure light probes are placed and baked in the Scene.
// Use Shadowmask mode and mixed lights to see occlusion probes approximating shadowness.
[RequireComponent(typeof(Camera))]
public class Simple : MonoBehaviour
{
    public Material material;

    private Matrix4x4[] transforms;
    private MaterialPropertyBlock properties;
    private Mesh cubeMesh;

    void Start()
    {
        const int kCount = 100;

        // Generate 100 random positions
        var positions = new Vector3[kCount];
        for (int i = 0; i < kCount; ++i)
            positions[i] = new Vector3(Random.Range(-20.0f, 20.0f), Random.Range(-20.0f, 20.0f), Random.Range(-20.0f, 20.0f));

        // Calculate probes at these positions
        var lightprobes = new UnityEngine.Rendering.SphericalHarmonicsL2[kCount];
        var occlusionprobes = new Vector4[kCount];
        LightProbes.CalculateInterpolatedLightAndOcclusionProbes(positions, lightprobes, occlusionprobes);

        // Put them into the MPB
        properties = new MaterialPropertyBlock();
        properties.CopySHCoefficientArraysFrom(lightprobes);
        properties.CopyProbeOcclusionArrayFrom(occlusionprobes);

        // Compute the transforms list
        transforms = new Matrix4x4[kCount];
        for (int i = 0; i < kCount; ++i)
            transforms[i] = Matrix4x4.Translate(positions[i]);

        // Create the cube mesh
        cubeMesh = GameObject.CreatePrimitive(PrimitiveType.Cube).GetComponent<MeshFilter>().sharedMesh;

        // Make sure the material property is assigned
        if (material == null || !material.enableInstancing)
            Debug.LogError("material must be assigned with one with instancing enabled.");
    }

    // OnPreCull happens before every culling, which is the perfect timing to inject DrawMesh* function calls.
    void OnPreCull()
    {
        if (material != null && material.enableInstancing)
        {
            RenderParams rp = new RenderParams(material)
            {
                matProps = properties,
                lightProbeUsage = UnityEngine.Rendering.LightProbeUsage.CustomProvided, // enable instancing for probes
                shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.On,
                receiveShadows = true
            };
            Graphics.RenderMeshInstanced(rp, cubeMesh, 0, transforms);
        }
    }
}
```

The example demonstrates how to leverage the baked light probes to enhance the visual quality of instanced rendering.

## CalculateInterpolatedLightAndOcclusionProbes(List\<Vector3>, List\<SphericalHarmonicsL2>, List\<Vector4>)

Calculate light probes and occlusion probes at the given world space positions.

```csharp
public static void CalculateInterpolatedLightAndOcclusionProbes(List<Vector3> positions, List<SphericalHarmonicsL2> lightProbes, List<Vector4> occlusionProbes)
```

### Parameters

**** (\[List\<Vector3>]\(https\://learn.microsoft.com/dotnet/api/system.collections.generic.list-1)): The array of world space positions used to evaluate the probes.**** (\[List\<SphericalHarmonicsL2>]\(https\://learn.microsoft.com/dotnet/api/system.collections.generic.list-1)): The array where the resulting light probes are written to.**** (\[List\<Vector4>]\(https\://learn.microsoft.com/dotnet/api/system.collections.generic.list-1)): The array where the resulting occlusion probes are written to.

### Remarks

If there are no probes baked in the Scene, the ambient probe will be written to the `lightProbes` array and `Vector4` (1,1,1,1) will be written to the `occlusionProbes` array.

ArgumentNullException is thrown if `positions` is `null`.

You can omit either `lightProbes` or `occlusionProbes` array by passing `null` to the function, but you cannot omit both at the same time. If both arrays are omitted, an ArgumentException is thrown. `lightProbes` and `occlusionProbes` should be calculated together for better performance.

For the overload which takes arrays as arguments, the `lightProbes` and `occlusionProbes` must have at least the same number of elements as the `positions` array.

For the overload which takes lists as arguments, the output lists will be resized to fit the size of the `positions` array if there is not enough space in the given lists.

The returned probes may be further used for instanced rendering by copying them to a MaterialPropertyBlock object via [MaterialPropertyBlock.CopySHCoefficientArraysFrom](/engine/6000.6/script-reference/unityengine/materialpropertyblock/copyshcoefficientarraysfrom.md) and [MaterialPropertyBlock.CopyProbeOcclusionArrayFrom](/engine/6000.6/script-reference/unityengine/materialpropertyblock/copyprobeocclusionarrayfrom.md).

```csharp
using UnityEngine;

// This script uses OnPreCull for the rendering. It is mandatory to put the script to a Camera object.
// Make sure light probes are placed and baked in the Scene.
// Use Shadowmask mode and mixed lights to see occlusion probes approximating shadowness.
[RequireComponent(typeof(Camera))]
public class Simple : MonoBehaviour
{
    public Material material;

    private Matrix4x4[] transforms;
    private MaterialPropertyBlock properties;
    private Mesh cubeMesh;

    void Start()
    {
        const int kCount = 100;

        // Generate 100 random positions
        var positions = new Vector3[kCount];
        for (int i = 0; i < kCount; ++i)
            positions[i] = new Vector3(Random.Range(-20.0f, 20.0f), Random.Range(-20.0f, 20.0f), Random.Range(-20.0f, 20.0f));

        // Calculate probes at these positions
        var lightprobes = new UnityEngine.Rendering.SphericalHarmonicsL2[kCount];
        var occlusionprobes = new Vector4[kCount];
        LightProbes.CalculateInterpolatedLightAndOcclusionProbes(positions, lightprobes, occlusionprobes);

        // Put them into the MPB
        properties = new MaterialPropertyBlock();
        properties.CopySHCoefficientArraysFrom(lightprobes);
        properties.CopyProbeOcclusionArrayFrom(occlusionprobes);

        // Compute the transforms list
        transforms = new Matrix4x4[kCount];
        for (int i = 0; i < kCount; ++i)
            transforms[i] = Matrix4x4.Translate(positions[i]);

        // Create the cube mesh
        cubeMesh = GameObject.CreatePrimitive(PrimitiveType.Cube).GetComponent<MeshFilter>().sharedMesh;

        // Make sure the material property is assigned
        if (material == null || !material.enableInstancing)
            Debug.LogError("material must be assigned with one with instancing enabled.");
    }

    // OnPreCull happens before every culling, which is the perfect timing to inject DrawMesh* function calls.
    void OnPreCull()
    {
        if (material != null && material.enableInstancing)
        {
            RenderParams rp = new RenderParams(material)
            {
                matProps = properties,
                lightProbeUsage = UnityEngine.Rendering.LightProbeUsage.CustomProvided, // enable instancing for probes
                shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.On,
                receiveShadows = true
            };
            Graphics.RenderMeshInstanced(rp, cubeMesh, 0, transforms);
        }
    }
}
```

The example demonstrates how to leverage the baked light probes to enhance the visual quality of instanced rendering.