LightProbes.CalculateInterpolatedLightAndOcclusionProbes

参数

描述

计算给定世界空间位置处的光照探针和遮挡探针。

如果场景中未烘焙任何探针，则环境探针会写入 lightProbes 数组，而 Vector4 (1,1,1,1) 会写入 occlusionProbes 数组。\ 如果 positions 为 null，则会引发 ArgumentNullException。\ 可以通过将 null 传递给函数来省略 lightProbes 或 occlusionProbes 数组，但是无法同时省略两者。如果同时省略这两个数组，则会抛出 ArgumentException。lightProbes 和 occlusionProbes 应一起计算，这样可提高性能。\ 对于采用数组作为参数的重载，lightProbes 和 occlusionProbes 必须至少具有与 positions 数组相同数量的元素。\ 对于采用列表作为参数的重载，如果给定列表中没有足够空间，则输出列表会调整大小以适应 positions 数组的大小。\ 返回的探针可以进一步用于实例化渲染，具体方法是通过 MaterialPropertyBlock.CopySHCoefficientArraysFrom 和 MaterialPropertyBlock.CopyProbeOcclusionArrayFrom 将它们复制到 MaterialPropertyBlock 对象。

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 &amp;&amp; material.enableInstancing)
        {
            var lightProbeUsage = UnityEngine.Rendering.LightProbeUsage.CustomProvided; // enable instancing for probes
            Graphics.DrawMeshInstanced(cubeMesh, 0, material, transforms, transforms.Length, properties, UnityEngine.Rendering.ShadowCastingMode.On, true, 0, null, lightProbeUsage);
        }
    }
}

该示例说明如何利用烘焙光照探针来增强实例化渲染的视觉品质。