Unity shader学习之屏幕后期处理效果之运动模糊

运动模糊，代码如下：

 using UnityEngine;

 public class MotionBlurRenderer : PostEffectRenderer
 {
     [Range(0.1f, 0.9f)]
     [SerializeField]
     float m_blurAmount = 0.1f;

     RenderTexture m_accumulationTexture;

     void OnDisable()
     {
         DestroyImmediate(m_accumulationTexture);
     }

     protected override void OnRenderImage(RenderTexture src, RenderTexture dest)
     {
         if (!m_accumulationTexture || m_accumulationTexture.width != src.width || m_accumulationTexture.height != src.height)
         {
             DestroyImmediate(m_accumulationTexture);
             m_accumulationTexture = new RenderTexture(src.width, src.height, );
             //m_accumulationTexture.hideFlags = HideFlags.HideAndDontSave;
             Graphics.Blit(src, m_accumulationTexture);
         }

         //m_accumulationTexture.MarkRestoreExpected();

         Mat.SetFloat("_BlurAmount", m_blurAmount);

         Graphics.Blit(src, m_accumulationTexture, Mat);
         Graphics.Blit(m_accumulationTexture, dest);

         base.OnRenderImage(src, dest);
     }

     protected override string ShaderName
     {
         get { return "Custom/Study/Motion Shader"; }
     }
 }

MotionBlurRenderer

对应shader如下：

 // Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

 Shader "Custom/Study/Motion Shader"
 {
     Properties
     {
         _MainTex ("Main Texture", 2D) = "white" {}
         _BlurAmount ("Blur Amount", Range(,)) = 0.5
     }

     SubShader
     {
         ZWrite Off
         ZTest Always
         Cull Off

         Pass
         {
             Blend SrcAlpha OneMinusSrcAlpha

             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag

             sampler2D _MainTex;
             fixed _BlurAmount;

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

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

             v2f vert(appdata v)
             {
                 v2f o;
                 o.pos = UnityObjectToClipPos(v.vertex);
                 o.uv = v.uv;
                 return o;
             }

             fixed4 frag(v2f i) : SV_TARGET
             {
                 fixed4 tex = tex2D(_MainTex, i.uv);
                 return fixed4(tex.rgb, _BlurAmount);
             }

             ENDCG
         }
     }

     Fallback Off
 }

Custom/Study/Motion Shader

效果如下：