CommandBuffer.SetShadowSamplingMode

参数

描述

添加“设置阴影采样模式”命令。

阴影贴图渲染纹理通常设置为使用比较过滤器来采样 - 采样器获取屏幕像素的阴影空间深度值，并根据阴影贴图中的深度值更小还是更大返回 0 或 1。这是默认的 ShadowSamplingMode.CompareDepths 模式，用于渲染阴影。

如果您要像在常规纹理中一样访问阴影贴图的值，请将采样模式设置为 ShadowSamplingMode.RawDepth。

在执行完当前 CommandBuffer 中的最后一条命令后，阴影贴图的采样模式将恢复默认值。

检查 SystemInfo.supportsRawShadowDepthSampling 以确认当前的运行时平台是否支持以此方式对阴影采样。很显然，DirectX9 不支持。

using UnityEngine;
using UnityEngine.Rendering;

[RequireComponent(typeof(Camera))]
public class RawShadowmapDepth : MonoBehaviour
{
    public Light m_Light;
    RenderTexture m_ShadowmapCopy;

    void Start()
    {
        RenderTargetIdentifier shadowmap = BuiltinRenderTextureType.CurrentActive;
        m_ShadowmapCopy = new RenderTexture(1024, 1024, 0);
        CommandBuffer cb = new CommandBuffer();

        // Change shadow sampling mode for m_Light's shadowmap.
        cb.SetShadowSamplingMode(shadowmap, ShadowSamplingMode.RawDepth);

        // The shadowmap values can now be sampled normally - copy it to a different render texture.
        cb.Blit(shadowmap, new RenderTargetIdentifier(m_ShadowmapCopy));

        // Execute after the shadowmap has been filled.
        m_Light.AddCommandBuffer(LightEvent.AfterShadowMap, cb);

        // Sampling mode is restored automatically after this command buffer completes, so shadows will render normally.
    }

    void OnRenderImage(RenderTexture src, RenderTexture dest)
    {
        // Display the shadowmap in the corner.
        Camera.main.rect = new Rect(0, 0, 0.5f, 0.5f);
        Graphics.Blit(m_ShadowmapCopy, dest);
        Camera.main.rect = new Rect(0, 0, 1, 1);
    }
}