调整Bloom

This commit is contained in:
SoulliesOfficial
2026-06-30 04:36:54 -04:00
parent c5b6b4a089
commit 8e4690c964
34 changed files with 1883 additions and 1150 deletions

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@@ -60,7 +60,10 @@ namespace Echovoid.Runtime.Behavior.Rendering
public static readonly int _BloomParams = Shader.PropertyToID("_BloomParams");
public static readonly int _BloomTint = Shader.PropertyToID("_BloomTint");
public static readonly int _AnimeBloom_BlurRadius = Shader.PropertyToID("_BlurRadius");
public static readonly int _AnimeBloom_KernelScale = Shader.PropertyToID("_KernelScale");
public static readonly int _BloomTex = Shader.PropertyToID("_BloomTex");
public static readonly int _SourceTexLowMip = Shader.PropertyToID("_SourceTexLowMip");
public static readonly int _BloomScatterParams = Shader.PropertyToID("_BloomScatterParams");
// --- Anime ACES ---
public static readonly int _TonemapParams = Shader.PropertyToID("_TonemapParams");

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@@ -9,118 +9,170 @@ Shader "SLS/Postprocessing/AnimeBloom"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
#include "Packages/com.unity.render-pipelines.core/Runtime/Utilities/Blit.hlsl"
// --- 参数定义 ---
float4 _BloomParams; // x: Intensity, y: Threshold, z: SoftKnee, w: Clamp
float4 _BloomTint; // 泛光染色
float _BlurRadius; // 模糊扩散半径 (控制光晕大小的关键)
// =====================================================
// 参数定义(与 Unity 原生 Bloom.shader 对齐)
// =====================================================
// _BloomScatterParams:
// x: scatter (已经过 C# 侧 Lerp(0.05, 0.95, userValue) 映射)
// y: clamp (最大亮度限制,防萤火虫)
// z: threshold (线性空间C# 侧已做 GammaToLinear)
// w: thresholdKnee (= threshold * 0.5f,硬编码 soft knee)
float4 _BloomScatterParams;
#define Scatter _BloomScatterParams.x
#define ClampMax _BloomScatterParams.y
#define Threshold _BloomScatterParams.z
#define ThresholdKnee _BloomScatterParams.w
// 纹理
// Composite 阶段参数x=intensity, y/z/w=tint.rgb (已归一化亮度)
float4 _BloomParams;
float4 _BloomTint; // 保留兼容,不再使用
float _KernelScale; // 采样跨度放大乘数,默认 1.0
// SourceTexLowMip: upsample 时的"低频大光晕"纹理 (lowMip)
TEXTURE2D(_SourceTexLowMip);
SAMPLER(sampler_SourceTexLowMip);
// 最终 bloom 结果纹理(传入 Composite Pass
TEXTURE2D(_BloomTex);
SAMPLER(sampler_BloomTex);
// --- 辅助函数Prefilter (提取高亮) ---
half3 Prefilter(half3 color)
// =====================================================
// HDR 编解码(与 Unity 原生 Bloom.shader 完全一致)
// 在线性工作流下 encode/decode 是 no-op但写清楚以防 gamma 空间项目
// =====================================================
half4 EncodeHDR(half3 color)
{
float threshold = _BloomParams.y;
float softKnee = _BloomParams.z;
float clampVal = _BloomParams.w;
// 1. 限制最大亮度 (防闪烁/萤火虫噪点)
color = min(color, clampVal);
// 2. 阈值计算 (使用 Soft Knee 曲线让过渡更自然)
// 标准公式:(Brightness - Threshold) / max(Brightness, 0.0001)
// 这里使用一个更平滑的曲线版本,防止高光边缘切变太硬
float brightness = Max3(color.r, color.g, color.b);
float soft = brightness - threshold + softKnee;
soft = clamp(soft, 0, 2 * softKnee);
soft = soft * soft / (4 * softKnee + 1e-4);
float contribution = max(soft, brightness - threshold);
contribution /= max(brightness, 1e-4);
return color * contribution;
}
// --- Pass 0: Prefilter ---
half4 FragPrefilter(Varyings input) : SV_Target
{
// 采样原图
half4 color = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, input.texcoord);
// 提取高亮
half3 bloom = Prefilter(color.rgb);
return half4(bloom, 1.0);
}
// --- Pass 1: Downsample (Kawase 4-Tap) ---
// 降采样:取 4 个对角像素的平均值,范围随分辨率降低而扩大
half4 FragDownsample(Varyings input) : SV_Target
{
float2 uv = input.texcoord;
float4 texelSize = _BlitTexture_TexelSize;
// 原生的 Kawase Offset 是 1.0(即 0.5 个对角像素距离),
// 这里加入 _BlurRadius 按比例扩大步幅,能够使用 3 次迭代跑出原版 6 次的扩散面积
float spreadOffset = 1.0 + _BlurRadius * 0.5;
float2 offset = texelSize.xy * spreadOffset;
half3 c0 = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv - offset).rgb;
half3 c1 = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2(offset.x, -offset.y)).rgb;
half3 c2 = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv - float2(offset.x, -offset.y)).rgb;
half3 c3 = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + offset).rgb;
half3 color = (c0 + c1 + c2 + c3) * 0.25;
#if UNITY_COLORSPACE_GAMMA
color = sqrt(color);
#endif
return half4(color, 1.0);
}
TEXTURE2D(_BloomMipDown);
SAMPLER(sampler_BloomMipDown);
// --- Pass 2: Upsample (Kawase 4-Tap + Scatter) ---
half4 FragUpsample(Varyings input) : SV_Target
half3 DecodeHDR(half4 data)
{
float2 uv = input.texcoord;
float4 texelSize = _BlitTexture_TexelSize;
// 原生的 Kawase 升采样偏移是 0.5。
// 配合宽幅降采样,这里稍微放大一点点就可以获得非常柔顺的大面积泛光
float spreadOffset = 0.5 + _BlurRadius * 0.2;
float2 offset = texelSize.xy * spreadOffset;
// 4-Tap 从更低分辨率纹理 (Up[i+1]) 采样外围光晕
half3 c0 = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv - offset * float2(1, 1)).rgb;
half3 c1 = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + offset * float2(1, -1)).rgb;
half3 c2 = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv - offset * float2(1, -1)).rgb;
half3 c3 = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + offset * float2(1, 1)).rgb;
half3 lowRes = (c0 + c1 + c2 + c3) * 0.25;
// 采样当前层级的高清纹理 (Down[i])
half3 highRes = SAMPLE_TEXTURE2D_X(_BloomMipDown, sampler_LinearClamp, uv).rgb;
// 【完全复刻 Unity 原生逻辑】: highRes + lowRes * scatter
// 这既保证了光晕向外漫射(低迭代扩散广),又保证了核心亮区的能量守恒!
float scatter = saturate(_BlurRadius);
half3 bloom = highRes + lowRes * scatter;
return half4(bloom, 1.0);
half3 color = data.xyz;
#if UNITY_COLORSPACE_GAMMA
color *= color;
#endif
return color;
}
// --- Pass 3: Composite (最终合成) ---
// =====================================================
// Pass 0: Prefilter — 提取超过阈值的高亮像素
// 与原生完全一致的 soft knee 公式
// =====================================================
half4 FragPrefilter(Varyings input) : SV_Target
{
float2 uv = input.texcoord;
half3 color = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv));
// 1. 亮度钳制(防止极亮萤火虫像素跳变)
color = min(color, ClampMax);
// 2. Soft Knee 阈值(与 Unity 原生公式完全一致)
half brightness = Max3(color.r, color.g, color.b);
half softness = clamp(brightness - Threshold + ThresholdKnee, 0.0, 2.0 * ThresholdKnee);
softness = (softness * softness) / (4.0 * ThresholdKnee + 1e-4);
half multiplier = max(brightness - Threshold, softness) / max(brightness, 1e-4);
color *= multiplier;
// 3. 防止 NaN 传播(负值在 EncodeHDR sqrt 时会产生 NaN
color = max(color, 0);
return EncodeHDR(color);
}
// =====================================================
// Pass 1: Dual Kawase Downsample
// 公式1/8 * (center*4 + 4corners)
// 采样次数5次相当于 3×3 box + 双线性权重,效果非常柔和)
// 与 Unity 原生 Bloom.shader FragDualDownsample 完全一致
// =====================================================
half4 FragDualDownsample(Varyings input) : SV_Target
{
float2 uv = input.texcoord;
// 乘以 _KernelScale在极低迭代次数下强制向外大跨步拉扯光晕
float2 ts = _BlitTexture_TexelSize.xy * _KernelScale;
// 中心点(权重 4
half3 c0 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv));
// 4 个对角偏移各 0.5 像素(恰好落在 4 像素的双线性插值中心)
half3 c1 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2( 0.5, 0.5) * ts));
half3 c2 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2(-0.5, 0.5) * ts));
half3 c3 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2(-0.5, -0.5) * ts));
half3 c4 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2( 0.5, -0.5) * ts));
// 加权平均:(c0*4 + c1+c2+c3+c4) / 8
half3 color = (1.0 / 8.0) * (c0 * 4.0 + c1 + c2 + c3 + c4);
return EncodeHDR(color);
}
// =====================================================
// Pass 2: Dual Kawase Upsample + Energy-Conserving Lerp
//
// 关键核心:与 Unity 原生 FragUpsample 一致的混合公式
// result = lerp(highMip, lowMip, Scatter)
//
// highMip (_BlitTexture) = 当前层的降采样纹理 Down[i](高分辨率,细节)
// lowMip (_SourceTexLowMip) = 上一层的升采样结果 Up[i+1](低分辨率,扩散光晕)
//
// lerp 是能量守恒的:总亮度 = (1-s)*high + s*low永远 ≤ max(high,low)
// 这是防止"死白"的数学保证。
// =====================================================
half4 FragDualUpsample(Varyings input) : SV_Target
{
float2 uv = input.texcoord;
// 同样乘以 _KernelScale
float2 ts = _BlitTexture_TexelSize.xy * _KernelScale;
// Dual Kawase 8-tap 升采样4 对角 + 4 正交
// 正交距离 = 1.0 texel对角距离 = 0.5 texel与原生完全一致
half3 c1 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2( 0.5, 0.5) * ts));
half3 c2 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2(-0.5, 0.5) * ts));
half3 c3 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2(-0.5, -0.5) * ts));
half3 c4 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2( 0.5, -0.5) * ts));
half3 c5 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2(-1.0, 0.0) * ts));
half3 c6 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2( 1.0, 0.0) * ts));
half3 c7 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2( 0.0, 1.0) * ts));
half3 c8 = DecodeHDR(SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv + float2( 0.0, -1.0) * ts));
// 加权平均 (4角×2 + 4正交×1) / 12产生柔和的钟形分布
half3 highMip = (1.0 / 12.0) * ((c1 + c2 + c3 + c4) * 2.0 + c5 + c6 + c7 + c8);
// lowMip = 来自更低分辨率层Up[i+1])的扩散光晕,双线性采样
half3 lowMip = DecodeHDR(SAMPLE_TEXTURE2D(_SourceTexLowMip, sampler_LinearClamp, uv));
// 【核心公式,与原生完全一致】
// Scatter 控制光晕扩散程度0=只有当前层细节1=完全使用模糊层
// 始终能量守恒,绝对不会产生死白
half3 result = lerp(highMip, lowMip, Scatter);
return EncodeHDR(result);
}
// =====================================================
// Pass 3: Composite — 将最终 bloom 叠加回原始画面
// _BloomParams.x = intensity
// _BloomParams.yzw = tint.rgb (亮度已归一化,仅携带色相/饱和度)
// =====================================================
half4 FragComposite(Varyings input) : SV_Target
{
float2 uv = input.texcoord;
// 原始画面
// 原始 HDR 画面
half4 baseColor = SAMPLE_TEXTURE2D_X(_BlitTexture, sampler_LinearClamp, uv);
// 泛光结果 (经过多次升采样后的最终纹理)
half3 bloom = SAMPLE_TEXTURE2D(_BloomTex, sampler_BloomTex, uv).rgb;
// 应用强度和染色
bloom *= _BloomParams.x * _BloomTint.rgb;
// Bloom 纹理(已经过多轮 Dual Kawase 升降采样)
half3 bloom = DecodeHDR(SAMPLE_TEXTURE2D(_BloomTex, sampler_BloomTex, uv));
// 叠加 (Additive)
// 也可以尝试 Screen 混合模式让光变得更柔和,但 Additive 最符合物理发光
// 应用强度和染色_BloomParams.yzw 是亮度归一化的 tint
float intensity = _BloomParams.x;
half3 tint = _BloomParams.yzw;
bloom *= intensity * tint;
// Additive 合并(物理正确的发光叠加)
return half4(baseColor.rgb + bloom, baseColor.a);
}
@@ -129,9 +181,9 @@ Shader "SLS/Postprocessing/AnimeBloom"
SubShader
{
Tags { "RenderType"="Opaque" "RenderPipeline"="UniversalPipeline" }
ZWrite Off Cull Off
ZWrite Off Cull Off ZTest Always
// 0: Prefilter
// Pass 0: Prefilter
Pass
{
Name "Bloom Prefilter"
@@ -141,28 +193,27 @@ Shader "SLS/Postprocessing/AnimeBloom"
ENDHLSL
}
// 1: Downsample
// Pass 1: Dual Kawase Downsample
Pass
{
Name "Bloom Downsample"
Name "Bloom Dual Downsample"
HLSLPROGRAM
#pragma vertex Vert
#pragma fragment FragDownsample
#pragma fragment FragDualDownsample
ENDHLSL
}
// 2: Upsample
// Pass 2: Dual Kawase Upsample + lerp(high, low, scatter)
Pass
{
Name "Bloom Upsample"
// 已在内部 Lerp无需外部 Additive Blend
Name "Bloom Dual Upsample"
HLSLPROGRAM
#pragma vertex Vert
#pragma fragment FragUpsample
#pragma fragment FragDualUpsample
ENDHLSL
}
// 3: Composite
// Pass 3: Composite
Pass
{
Name "Bloom Composite"

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@@ -8,39 +8,50 @@ namespace SLSUtilities.Rendering.PostProcessing
[System.Serializable, VolumeComponentMenu("SLS/Postprocessing/Anime Bloom")]
public class AnimeBloom : ScriptablePostProcessorVolume
{
// 【核心修改】:放在 ToneMapping 之前执行BeforePostProcess配合 ACES 才能彻底解决“高光泛白”问题
// BeforePostProcess: 在 ToneMapping 之前运行,确保 HDR bloom 颜色不被截断
// 这与 Unity 原生 Bloom 的执行阶段完全一致
public override CustomPostProcessInjectionPoint InjectionPoint => CustomPostProcessInjectionPoint.BeforePostProcess;
public override int OrderInInjectionPoint => 5; // 放在 Vignette 之前
public override int OrderInInjectionPoint => 5;
[Header("Glow Settings")]
[Tooltip("泛光强度。值越大越亮。")]
public ClampedFloatParameter intensity = new(0f, 0f, 10f);
public ClampedFloatParameter intensity = new(1f, 0f, 10f);
[Tooltip("阈值。亮度超过此值的像素才会发光。\n关键设为 1.1 可以过滤掉白墙(1.0),只让灯光发光。")]
public MinFloatParameter threshold = new(1.1f, 0f); // 默认设为 1.1
// 注意threshold 在 Gamma 空间中设置C# 侧会转为 Linear。
// 0.9 在 gamma 空间 ≈ 0.79 在 linear 空间,这与 Unity 原生默认行为完全一致。
public MinFloatParameter threshold = new(0.9f, 0f);
[Tooltip("柔膝 (Soft Knee)。让阈值过渡更平滑,避免高光边缘有硬切痕迹。")]
public ClampedFloatParameter softKnee = new(0.5f, 0f, 1f);
[Header("Scatter")]
// scatter 在 [0,1] 范围内由用户设置。
// C# 侧映射Mathf.Lerp(0.05f, 0.95f, scatter.value),与 Unity 原生完全一致。
// 低值 = 光晕聚拢,高值 = 光晕向外大范围扩散。
public ClampedFloatParameter scatter = new(0.7f, 0f, 1f);
[Tooltip("最大亮度钳制。防止极亮像素(如太阳)产生乱跳的噪点。")]
public MinFloatParameter clamp = new(65472f, 1f); // 默认很大,基本不限制
public MinFloatParameter clamp = new(65472f, 1f);
[Header("Anime Style")]
[Tooltip("扩散半径。稍微增加扩展范围来弥补低迭代带来的发光不足。")]
public ClampedFloatParameter scatter = new(0.85f, 0f, 5f); // 推荐增量以适应低迭代
[Header("Iterations")]
// 迭代次数Dual Kawase 每层只需 1 Pass性能远低于原生双趟高斯。
// 4 次迭代 Dual Kawase ≈ 原生 6 次双趟高斯的扩散范围,但 Pass 数只有其 1/3。
public ClampedIntParameter diffusion = new(4, 1, 8);
[Tooltip("迭代次数。针对移动端带宽优化,建议控制在 2~3 次。")]
public ClampedIntParameter diffusion = new(3, 1, 4); // 移动端性能优化最高4次
[Header("Optimization (Mobile)")]
[Tooltip("初始降采样倍率(首趟大幅压缩分辨率)。\n1=原生半分辨率(1/2)2=1/4分辨率3=1/8分辨率。\n调大此值可用极低的迭代次数跑出巨大且柔和的光晕大幅节省 GPU 带宽。")]
public ClampedIntParameter initialDownscaleShift = new(1, 1, 3);
[Tooltip("采样偏移跨度放大Kernel Scale。\n1.0=原生标准跨度。适度放大(如1.2-1.5)可拉扯光晕扩散范围,但过大会产生轻微十字星/方格马赛克。")]
public ClampedFloatParameter kernelScale = new(1.0f, 0.5f, 3.0f);
[Tooltip("泛光染色。可以做粉色霓虹、蓝色科技光等效果。")]
[Header("Tint")]
// tint 染色C# 侧会归一化亮度(只保留色相/饱和度),与原生行为一致。
// 这样调整 tint 颜色不会意外改变 bloom 总亮度。
public ColorParameter tint = new(Color.white, true, true, true);
// 内部使用的 RT 数组
private RTHandle[] _bloomPyramidUp;
private RTHandle[] _bloomPyramidDown;
private const int k_MaxPyramidSize = 6; // 减少不必要的最大数组长度
// RT 数组(仅 Down 金字塔 + Up 金字塔,数量与 diffusion 对齐)
private RTHandle[] _bloomMipDown;
private RTHandle[] _bloomMipUp;
private const int k_MaxMips = 8;
public override string GetShaderName() => "SLS/Postprocessing/AnimeBloom";
public override bool IsActive() => intensity.value > 0f;
public override void Render(CommandBuffer cmd, ref RenderingData renderingData, RTHandle source, RTHandle destination)
{
@@ -50,86 +61,123 @@ namespace SLSUtilities.Rendering.PostProcessing
desc.msaaSamples = 1;
desc.depthBufferBits = 0;
// 1. 设置参数
Vector4 bloomParams = new Vector4(intensity.value, threshold.value, softKnee.value, clamp.value);
material.SetVector(InternalShaderHelpers.ID._BloomParams, bloomParams);
material.SetVector(InternalShaderHelpers.ID._BloomTint, tint.value);
material.SetFloat(InternalShaderHelpers.ID._BlurRadius, scatter.value);
// ─────────────────────────────────────────────────────────────
// 1. 参数打包(完全对齐 Unity SetupBloom 的计算逻辑)
// ─────────────────────────────────────────────────────────────
// 2. 初始化金字塔数组
int iterations = Mathf.Clamp(diffusion.value, 1, k_MaxPyramidSize);
// 确保 RT 数组大小足够
if (_bloomPyramidUp == null || _bloomPyramidUp.Length != k_MaxPyramidSize)
// scatter: 用户 [0,1] → shader [0.05, 0.95](与原生 Lerp 映射一致)
float scatterMapped = Mathf.Lerp(0.05f, 0.95f, scatter.value);
// threshold: Gamma → Linear原生使用 GammaToLinearSpace 转换)
float thresholdLinear = Mathf.GammaToLinearSpace(threshold.value);
float thresholdKnee = thresholdLinear * 0.5f; // 硬编码 soft knee与原生一致
material.SetVector(InternalShaderHelpers.ID._BloomScatterParams,
new Vector4(scatterMapped, clamp.value, thresholdLinear, thresholdKnee));
material.SetFloat(InternalShaderHelpers.ID._AnimeBloom_KernelScale, kernelScale.value);
// ─────────────────────────────────────────────────────────────
// 2. Tint 归一化(原生做法:亮度归一为 1只携带色相/饱和度)
// 这样 tint 调整颜色时不会改变 bloom 总亮度。
// ─────────────────────────────────────────────────────────────
Color tintLinear = tint.value.linear;
float luma = 0.2126f * tintLinear.r + 0.7152f * tintLinear.g + 0.0722f * tintLinear.b;
Color tintNormalized = luma > 0f ? tintLinear * (1f / luma) : Color.white;
// 将 intensity 和归一化 tint 一并打包进 _BloomParams原生 uber 方式)
material.SetVector(InternalShaderHelpers.ID._BloomParams,
new Vector4(intensity.value, tintNormalized.r, tintNormalized.g, tintNormalized.b));
// ─────────────────────────────────────────────────────────────
// 3. RT 数组初始化
// ─────────────────────────────────────────────────────────────
int mipCount = Mathf.Clamp(diffusion.value, 1, k_MaxMips);
if (_bloomMipDown == null || _bloomMipDown.Length != k_MaxMips)
{
_bloomPyramidUp = new RTHandle[k_MaxPyramidSize];
_bloomPyramidDown = new RTHandle[k_MaxPyramidSize];
_bloomMipDown = new RTHandle[k_MaxMips];
_bloomMipUp = new RTHandle[k_MaxMips];
}
// 3. Prefilter Pass (提取高亮)
// 先降一半分辨率,节省性能且增加模糊感
desc.width = Mathf.Max(1, desc.width >> 1);
desc.height = Mathf.Max(1, desc.height >> 1);
RenderingUtils.ReAllocateIfNeeded(ref _bloomPyramidDown[0], desc, FilterMode.Bilinear, TextureWrapMode.Clamp, name: "_BloomMipDown0");
RenderingUtils.ReAllocateIfNeeded(ref _bloomPyramidUp[0], desc, FilterMode.Bilinear, TextureWrapMode.Clamp, name: "_BloomMipUp0");
// ─────────────────────────────────────────────────────────────
// 4. Prefilter提取高亮像素 + 初始激进降采样)
// 根据用户选择,起始分辨率可能是 1/2, 1/4 或 1/8。
// ─────────────────────────────────────────────────────────────
int shift = initialDownscaleShift.value;
desc.width = Mathf.Max(1, desc.width >> shift);
desc.height = Mathf.Max(1, desc.height >> shift);
// Source -> Down[0] (Prefilter)
Blitter.BlitCameraTexture(cmd, source, _bloomPyramidDown[0], material, 0);
RenderingUtils.ReAllocateIfNeeded(ref _bloomMipDown[0], desc, FilterMode.Bilinear,
TextureWrapMode.Clamp, name: "_BloomDown0");
// 4. Downsample Loop (降采样金字塔)
int lastDown = 0;
for (int i = 1; i < iterations; i++)
// Source → Down[0] via Pass 0 (Prefilter)
Blitter.BlitCameraTexture(cmd, source, _bloomMipDown[0], material, 0);
// ─────────────────────────────────────────────────────────────
// 5. Downsample LoopDual Kawase 降采样金字塔Pass 1
// 每次分辨率减半,产生多层不同尺度的模糊纹理
// ─────────────────────────────────────────────────────────────
for (int i = 1; i < mipCount; i++)
{
// 每次分辨率减半
desc.width = Mathf.Max(1, desc.width >> 1);
desc.width = Mathf.Max(1, desc.width >> 1);
desc.height = Mathf.Max(1, desc.height >> 1);
RenderingUtils.ReAllocateIfNeeded(ref _bloomPyramidDown[i], desc, FilterMode.Bilinear, TextureWrapMode.Clamp, name: "_BloomMipDown" + i);
RenderingUtils.ReAllocateIfNeeded(ref _bloomPyramidUp[i], desc, FilterMode.Bilinear, TextureWrapMode.Clamp, name: "_BloomMipUp" + i);
RenderingUtils.ReAllocateIfNeeded(ref _bloomMipDown[i], desc, FilterMode.Bilinear,
TextureWrapMode.Clamp, name: "_BloomDown" + i);
// Down[i-1] -> Down[i]
Blitter.BlitCameraTexture(cmd, _bloomPyramidDown[i - 1], _bloomPyramidDown[i], material, 1);
lastDown = i;
// Down[i-1] Down[i] via Pass 1 (Dual Kawase Downsample)
Blitter.BlitCameraTexture(cmd, _bloomMipDown[i - 1], _bloomMipDown[i], material, 1);
}
// 5. Upsample Loop (升采样并混合)
// 从最小的一张开始,往上叠加
// 先把最小的 Down 直接拷给 Up
Blitter.BlitCameraTexture(cmd, _bloomPyramidDown[lastDown], _bloomPyramidUp[lastDown]);
// ─────────────────────────────────────────────────────────────
// 6. Upsample LoopDual Kawase 升采样 + lerp(high, low, scatter)
//
// 与 Unity 原生完全一致的数据流向:
// _BlitTexture = highMip = Down[i] (当前层高分辨率细节)
// _SourceTexLowMip = lowMip = Up[i+1] 或 Down[last](低分辨率扩散光晕)
// output = Up[i]
//
// 从最底层开始,逐层往上合并,最终 Up[0] 就是完整的 bloom 纹理
// ─────────────────────────────────────────────────────────────
for (int i = lastDown - 1; i >= 0; i--)
// 分配所有 Up RT从最大 mip 往上,分辨率逐步翻倍)
// 由于 desc 已经在 downsample 中不断减半,我们要重新从 Down[i] 读尺寸
for (int i = mipCount - 1; i >= 0; i--)
{
// 设置上一级 Up 为输入
// Upsample Pass 会混合Up[i+1] (Blur) + Down[i] (High Res Detail)
// 这里我们稍微简化逻辑:直接把 Up[i+1] 升采样并叠加到 Up[i] 上
// 第二步:把 Up[i+1] (LowRes) 和 Down[i] (HighRes) 一起传给 Shader
// 在 Shader 内部执行 Lerp 能量守恒融合,彻底替代会导致死白的 Additive 叠加模式
material.SetTexture("_BloomMipDown", _bloomPyramidDown[i]);
Blitter.BlitCameraTexture(cmd, _bloomPyramidUp[i + 1], _bloomPyramidUp[i], material, 2);
RenderingUtils.ReAllocateIfNeeded(ref _bloomMipUp[i],
_bloomMipDown[i].rt.descriptor, FilterMode.Bilinear,
TextureWrapMode.Clamp, name: "_BloomUp" + i);
}
// 6. Composite (合成)
// 此时 _bloomPyramidUp[0] 包含了最终的泛光纹理
material.SetTexture(InternalShaderHelpers.ID._BloomTex, _bloomPyramidUp[0]);
// Source + BloomTex -> Destination
// 最底层lowMip = Down[last]highMip 也是 Down[last](无 low 可用,直接 lerp 自身,结果仍 = Down[last]
// 简化做法:直接将 Down[last] 拷到 Up[last] 作为起点
Blitter.BlitCameraTexture(cmd, _bloomMipDown[mipCount - 1], _bloomMipUp[mipCount - 1]);
// 从第二底层开始向上 upsample
for (int i = mipCount - 2; i >= 0; i--)
{
// highMip当前层降采样纹理 Down[i],作为 Blit 的 source_BlitTexture
// lowMip 上一级升采样结果 Up[i+1],通过 SetTexture 传入
cmd.SetGlobalTexture(InternalShaderHelpers.ID._SourceTexLowMip, _bloomMipUp[i + 1]);
Blitter.BlitCameraTexture(cmd, _bloomMipDown[i], _bloomMipUp[i], material, 2);
}
// ─────────────────────────────────────────────────────────────
// 7. Composite将 bloom 叠加回原始画面Pass 3
// ─────────────────────────────────────────────────────────────
material.SetTexture(InternalShaderHelpers.ID._BloomTex, _bloomMipUp[0]);
Blitter.BlitCameraTexture(cmd, source, destination, material, 3);
}
// 清理 RT
public void Dispose()
{
if (_bloomPyramidDown != null)
if (_bloomMipDown == null) return;
for (int i = 0; i < _bloomMipDown.Length; i++)
{
for (int i = 0; i < _bloomPyramidDown.Length; i++)
{
if (_bloomPyramidDown[i] != null) _bloomPyramidDown[i].Release();
if (_bloomPyramidUp[i] != null) _bloomPyramidUp[i].Release();
}
_bloomMipDown[i]?.Release();
_bloomMipUp[i]?.Release();
}
}
public override bool IsActive() => intensity.value > 0f;
}
}