Unity URP管线如何实现屏幕后处理

URP管线可扩展的自己的 RendererFeature，这里写了一个屏幕后处理的demo，首先shader如下：

 1 Shader "MyURP/Kerry/PostProcess/URPFeature_PostProcessDemo"
 2 {
 3     Properties
 4     {
 5         _MainTex("Main Texture", 2D) = "white" {}
 6         _Color("test", Color) = (1,1,1,1)
 7     }
 8 
 9     SubShader
10     {
11         Tags
12         {
13             "RenderType" = "Opaque"
14             "RenderPipeline" = "UniversalPipeline"
15         }
16 
17         Pass
18         {
19             Cull Off
20             ZWrite Off
21             ZTest Always
22 
23             HLSLPROGRAM
24             #pragma vertex vert
25             #pragma fragment frag
26             #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
27 
28             TEXTURE2D(_MainTex); SAMPLER(sampler_MainTex);
29             half4 _Color;
30 
31             struct appdata
32             {
33                 float4 vertex : POSITION;
34                 float2 uv : TEXCOORD0;
35             };
36 
37             struct v2f
38             {
39                 float4 pos : SV_POSITION;
40                 float2 uv : TEXCOORD0;
41             };
42 
43             v2f vert(appdata v)
44             {
45                 v2f o;
46                 o.pos = mul(UNITY_MATRIX_MVP, v.vertex);
47                 o.uv = v.uv;
48                 return o;
49             }
50 
51             half4 frag(v2f i) : SV_TARGET
52             {
53                 return SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, i.uv) * _Color;
54             }
55 
56             ENDHLSL
57         }
58     }
59 
60     FallBack "Hidden/Universal Render Pipeline/FallbackError"
61 }

可以看到，这里就是输入一个颜色并叠加到屏幕颜色上。

C# RenderFeature代码如下：

 1 using System;
 2 using UnityEngine;
 3 using UnityEngine.Rendering;
 4 using UnityEngine.Rendering.Universal;
 5 
 6 public class URPFeature_PostProcessDemo : ScriptableRendererFeature
 7 {
 8     class URPPass_PostProcessDemo : ScriptableRenderPass
 9     {
10         Settings m_Settings;
11         RenderTargetIdentifier m_source;
12         RenderTargetIdentifier m_dest;
13 
14         public URPPass_PostProcessDemo(Settings settings)
15         {
16             m_Settings = settings;
17         }
18 
19         public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
20         {
21             m_source = renderingData.cameraData.renderer.cameraColorTarget;
22 
23             int tempRTName = Shader.PropertyToID("URPFeature_PostProcessDemo_TempRT");
24             cmd.GetTemporaryRT(tempRTName, renderingData.cameraData.cameraTargetDescriptor);
25             m_dest = new RenderTargetIdentifier(tempRTName);
26         }
27 
28         public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
29         {
30             m_Settings.m_mat.SetColor("_Color", m_Settings.m_Color);
31 
32             CommandBuffer cmd = CommandBufferPool.Get("URPFeature_PostProcessDemo_cmd");
33             Blit(cmd, m_source, m_dest, m_Settings.m_mat, 0);
34             Blit(cmd, m_dest, m_source);
35             context.ExecuteCommandBuffer(cmd);
36             CommandBufferPool.Release(cmd);
37         }
38     }
39 
40     [Serializable]
41     public class Settings
42     {
43         public Material m_mat;
44         public Color m_Color = Color.white;
45     }
46 
47     [SerializeField]
48     Settings m_Settings;
49     URPPass_PostProcessDemo m_pass;
50 
51 
52     public override void Create()
53     {
54         m_pass = new URPPass_PostProcessDemo(m_Settings);
55     }
56 
57     public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
58     {
59         if (m_Settings.m_mat)
60         {
61             renderer.EnqueuePass(m_pass);
62         }
63     }
64 
65 
66 }

最后，我们把这个feature加到URP管线中，如下：

 调整颜色值，发现屏幕颜色发生了改变：

 转载请注明出处：https://www.cnblogs.com/jietian331/p/17032259.html