Unity CommandBuffer

    struct v2f {
        float4 pos : SV_POSITION;
        float4 uv : TEXCOORD0;
        float3 ray : TEXCOORD1;
    };    
    
    // Common lighting data calculation (direction, attenuation, ...)
    void DeferredCalculateLightParams(
        unity_v2f_deferred_instanced i,
        out float3 outWorldPos,
        out float2 outUV,
        out half3 outLightDir,
        out float outAtten,
        out float outFadeDist)
    {
        i.ray = i.ray * (_ProjectionParams.z / i.ray.z);
        float2 uv = i.uv.xy / i.uv.w;

        // read depth and reconstruct world position
        float depth = SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, uv);
        depth = Linear01Depth(depth);
        float4 vpos = float4(i.ray * depth, 1);
        float3 wpos = mul(unity_CameraToWorld, vpos).xyz;

        float fadeDist = UnityComputeShadowFadeDistance(wpos, vpos.z);

        float3 lightPos = float3(unity_ObjectToWorld[0][3], unity_ObjectToWorld[1][3], unity_ObjectToWorld[2][3]);
        float3 tolight = wpos - lightPos;
        half3 lightDir = -normalize(tolight);

        float att = dot(tolight, tolight) * (距离平方倒数); // 光源的最远照亮距离
        float atten = tex2D (_LightTextureB0, att.rr).UNITY_ATTEN_CHANNEL;

        atten *= UnityDeferredComputeShadow(tolight, fadeDist, uv);

        outWorldPos = wpos;
        outUV = uv;
        outLightDir = lightDir;
        outAtten = atten;
        outFadeDist = fadeDist;
    }