后处理 - 屏幕置灰

 

 

置灰的shader

Shader "My/PostEffectGray"
{
    Properties
    {
        _MainTex("Texture", 2D) = "white" {}
    }
    SubShader
    {
        Tags { "RenderType" = "Opaque" }
        LOD 100

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float4 vertex : SV_POSITION;
                float2 uv : TEXCOORD0;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;

            v2f vert(appdata v) //顶点着色器
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex); //local空间的顶点坐标转换到裁剪空间
                o.uv = TRANSFORM_TEX(v.uv, _MainTex); //应用贴图的tiling和offset
                return o;
            }

            fixed4 frag(v2f i) : SV_Target //片元着色器(逐像素)
            {
                fixed4 c = tex2D(_MainTex, i.uv); //采样贴图像素颜色
                c.rgb = Luminance(c.rgb); //应用颜色置灰公式
                return c;
            }
            ENDCG
        }
    }
}

 

 PostEffectsBase来自shader入门精要第12章

using UnityEngine;

public class PostEffectGray : PostEffectsBase
{

    public Shader m_grayShader;
    private Material m_grayMaterial;

    public Material material
    {
        get
        {
            m_grayMaterial = CheckShaderAndCreateMaterial(m_grayShader, m_grayMaterial);
            return m_grayMaterial;
        }
    }


    void OnRenderImage(RenderTexture src, RenderTexture dest)
    {
        if (null != material)
        {
            Graphics.Blit(src, dest, material);
        }
        else
        {
            Graphics.Blit(src, dest);
        }
    }

}

 

参考

unity 常见的置灰处理_天涯过客TYGK的博客-CSDN博客_unity置灰mash