URP 14
URP 14 对应Unity 2022.2对于2021lts版本的URP 12中后处理的API有些许改变，需要参考官方文档的改变。而其中最大的改变来自于RTHandle的引入。
以一个DesaturateFeature为例。在DesaturateFeature.cs中改变比较大的是加入一个SetupRenderPasses来帮助创建Materail和传递参数，而不是传统的写法在Create()中。
public override void SetupRenderPasses(ScriptableRenderer renderer, in RenderingData renderingData)
{
Material material = CoreUtils.CreateEngineMaterial(shader);
desaturateRenderPass.ConfigureInput(ScriptableRenderPassInput.Color);
desaturateRenderPass.Setup(material, "DesaturatedRenderPass",renderingData);
}
然后写内部的DesaturateRenderPass 类。
- 变化一是RenderTargetHandle.Init("_CustomPassHandle")方式的改变为
var colorCopyDescriptor = renderingData.cameraData.cameraTargetDescriptor;
colorCopyDescriptor.depthBufferBits = (int) DepthBits.None;
RenderingUtils.ReAllocateIfNeeded(ref m_CopiedColor, colorCopyDescriptor, name: "_FullscreenPassColorCopy");
变化二：command buffer的GetTemporaryRT和ReleaseTemporaryRT被弃用。
官方推荐使用Blitter.BlitCameraTexture方法把原始的RT添加我们自定义的material然后再传递回去。代码实现如下
CommandBuffer cmd = CommandBufferPool.Get();
var cameraData = renderingData.cameraData;
using (new ProfilingScope(cmd, profilingSampler))
{
var source =cameraData.renderer.cameraColorTargetHandle;
passMaterial.SetTexture(m_BlitTextureShaderID, copiedColor);
Blitter.BlitCameraTexture(cmd, source, copiedColor, passMaterial, 0);
Blitter.BlitCameraTexture(cmd, copiedColor, source);
context.ExecuteCommandBuffer(cmd);
cmd.Clear();
}
参考官方的案例，完整写一个ColorTint的实例
Shader的部分可以十分简化，Vert在Blit.hlsl中官方已经帮忙处理好，这里只需要写frag的逻辑部分，太香了。
Shader "ColorBlit"
{
SubShader
{
Tags { "RenderType"="Opaque" "RenderPipeline" = "UniversalPipeline"}
LOD 100
ZWrite Off Cull Off
Pass
{
Name "ColorTintPass"
HLSLPROGRAM
#include "Packages/com.unity.render-pipelines.core/Runtime/Utilities/BlitColorAndDepth.hlsl"
#pragma vertex Vert
#pragma fragment frag
float4 _ColorTint;
half4 frag (Varyings input) : SV_Target
{
half4 color = FragColorAndDepth(input).color;
color *= _ColorTint;
return color;
}
ENDHLSL
}
}
}
完整的ColorTintRenderFeature部分。思路如下，用一个colorTintSettings做UI接住全部的设置内容。重写一个SetupRenderPasses来传递以前在Create()中传递的内容，创建就好好创建，设置参数就好好设置参数，嗯恒河里。RenderFeature class基本就这样没什么可以说的，与urp 12就这么点区别。哦对，在传递相机的部分，用renderer.cameraColorTargetHandle而不是cameraColorTarget。换句话说，unity 换了RThandle这个API，跟着换就行，虽然老的也能用，但是Unity官方论坛的讨论结果是未来RThandle会成为主流，你现在学会对未来没坏处。
这里偷懒不想创建Volume，也不想多创建一个c#脚本来写colorTintPass，直接用一个intenal class来写吧。首先最大的区别就是用RThandle替代以前的API。重写OnCameraSetup()，调用ConfigureTarget()来设置当前Target，也就是刚刚传递过来的cameraColorTargetHandle。
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;
public class ColorTintRenderFeature : ScriptableRendererFeature
{
[System.Serializable]
public class ColorTintSettings
{
public Shader colorTintShader;
public RenderPassEvent passEvent = RenderPassEvent.BeforeRenderingPostProcessing;
public ScriptableRenderPassInput requirements = ScriptableRenderPassInput.Color;
[Header("ColorTint Settings")] [Space(10)]
public Color colorTint = Color.red;
}
public ColorTintSettings colorTintSettings = new ColorTintSettings();
private ColorTintPass colorTintPass;
public override void SetupRenderPasses(ScriptableRenderer renderer, in RenderingData renderingData)
{
colorTintPass.ConfigureInput(colorTintSettings.requirements);
colorTintPass.Setup(renderer.cameraColorTargetHandle, colorTintSettings);
}
public override void Create()
{
colorTintPass = new ColorTintPass();
colorTintPass.renderPassEvent = colorTintSettings.passEvent;
}
public override void AddRenderPasses(ScriptableRenderer renderer, ref RenderingData renderingData)
{
renderer.EnqueuePass(colorTintPass);
}
protected override void Dispose(bool disposing)
{
colorTintPass.Dispose();
}
public class ColorTintPass : ScriptableRenderPass
{
private ProfilingSampler profilingSampler = new ProfilingSampler(nameof(ColorTintPass));
private ColorTintSettings colorTintSettings;
private Material colorTintMaterial;
private static readonly int ColorTintID = Shader.PropertyToID("_ColorTint");
private static readonly int BlitTextureID = Shader.PropertyToID("_BlitTexture");
private RTHandle source;
private RTHandle copiedColor;
public void Setup(RTHandle colorHandle, ColorTintSettings colorTintSettings)
{
this.colorTintSettings = colorTintSettings;
Shader shader = colorTintSettings.colorTintShader;
if (shader == null)
return;
colorTintMaterial = CoreUtils.CreateEngineMaterial(shader);
source = colorHandle;
}
public void Dispose()
{
source.Release();
CoreUtils.Destroy(colorTintMaterial);
}
public override void OnCameraSetup(CommandBuffer cmd, ref RenderingData renderingData)
{
ConfigureTarget(source);
var colorCopyDescriptor = renderingData.cameraData.cameraTargetDescriptor;
colorCopyDescriptor.depthBufferBits = (int) DepthBits.None;
RenderingUtils.ReAllocateIfNeeded(ref copiedColor, colorCopyDescriptor, name: "_FullscreenPassColorCopy");
}
public override void Execute(ScriptableRenderContext context, ref RenderingData renderingData)
{
if (colorTintMaterial == null)
return;
CommandBuffer cmd = CommandBufferPool.Get();
var cameraData = renderingData.cameraData;
using (new ProfilingScope(cmd, profilingSampler))
{
colorTintMaterial.SetColor(ColorTintID, colorTintSettings.colorTint);
Blitter.BlitCameraTexture(cmd, source, copiedColor);
colorTintMaterial.SetTexture(BlitTextureID, copiedColor);
Blitter.BlitCameraTexture(cmd, copiedColor, source, colorTintMaterial, 0);
}
context.ExecuteCommandBuffer(cmd);
cmd.Clear();
CommandBufferPool.Release(cmd);
}
}
}
RT的初始化方法
RenderingUtils.ReAllocateIfNeeded(ref copiedColor, colorCopyDescriptor, name: "_FullscreenPassColorCopy");
这里偷懒直接用Blitter.BlitCameraTexture(cmd, source, source, colorTintMaterial, 0) 直接把source当作最终的RT并写入colorTintMaterial，按照逻辑的话，写成就和之前cmd.blit写出来到一个暂时的RT上再写入原source一样了。
Blitter.BlitCameraTexture(cmd, source, temp, colorTintMaterial, 0);
colorTintMaterial.SetColor(ColorTintID, colorTintSettings.colorTint);
Blitter.BlitCameraTexture(cmd, temp, source);
最终效果如图
