URP管线中自定义Bloom

最新推荐文章于 2025-09-16 08:15:00 发布

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最新推荐文章于 2025-09-16 08:15:00 发布 · 4k 阅读

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#URP中Bloom #高斯模糊 #自定义后处理Bloom

本文介绍如何在不使用HDR的情况下实现Bloom效果。通过Unity的URP系统，利用自定义后处理堆栈实现Bloom算法。文章详细介绍了Bloom效果的实现步骤，包括预过滤、水平垂直模糊及融合等过程。

非HDR开启bloom的效果
主要是URP作者的教程

在这里插入图片描述

using System.Collections;
using System.Collections.Generic;
using System.IO;
using UnityEditor;
using UnityEngine;
using UnityEngine.Rendering;

partial class PostFXStack
{
   
   
    private const string bufferName = "Post FX";
    CommandBuffer buffer = new CommandBuffer()
    {
   
   
        name = bufferName
    };

    private ScriptableRenderContext context;
    private Camera camera;
    private PostFXSettings settings;

    private int fxSourceId = Shader.PropertyToID("_PostFXSource");
    private int fxSource2Id = Shader.PropertyToID("_PostFXSource2");
    private int bloomBucibicUpsamplingId = Shader.PropertyToID("_BloomBicubicUpsampling");
    private int bloomPrefilterId = Shader.PropertyToID("_BloomPrefilter");
    private int bloomThresholdId = Shader.PropertyToID("_BloomThreshold");
    private int bloomIntensityId = Shader.PropertyToID("_BloomIntensity");
    public bool IsActive => settings != null;
    private const int maxBloomPyramidLevels = 16;
    private int bloomPyramidId;
    enum Pass
    {
   
   
        // BloomPrefilter,
        // BloomCombine,
        BloomVertical,
        BloomHorizontal,
        BloomCombine,
        BloomPrefilter,
        Copy,
    }

    public PostFXStack()
    {
   
   
        bloomPyramidId = Shader.PropertyToID("_BloomPyramid0");
        for (int i = 0; i < maxBloomPyramidLevels * 2; i++)
        {
   
   
            // id的结果是 申请的顺序 +1的结果
            Shader.PropertyToID("_BloomPyramid"+i);
        }
    }


    void DoBloom(int sourceId)
    {
   
   
        buffer.BeginSample("Bloom");
        PostFXSettings.BloomSettings bloom = settings.Bloom;
        int width = camera.pixelWidth / 2, height = camera.pixelHeight / 2;
        
        Vector4 threshold;
        threshold.x = Mathf.GammaToLinearSpace(bloom.threshold);
        threshold.y = threshold.x * bloom.thresholdKnee;
        threshold.z = threshold.y * 2f;
        threshold.w = 0.25f /( threshold.y + 0.00001f);
        threshold.y -= threshold.x;
        buffer.SetGlobalVector(bloomThresholdId,threshold);
        
        
        
        RenderTextureFormat format = RenderTextureFormat.Default;
        buffer.GetTemporaryRT(bloomPrefilterId,width,height,0,FilterMode.Bilinear,format);
        Draw(sourceId,bloomPrefilterId,Pass.BloomPrefilter);
        width /= 2;
        height /= 2;
        int formId = bloomPrefilterId