Skip to content

Commit abdb107

Browse files
przemyslawzaworskiprzemyslawzaworski
authored
HDR Bloom and Eye Adaptation (compact code)
1 parent 105ef7f commit abdb107

File tree

5 files changed

+632
-0
lines changed

5 files changed

+632
-0
lines changed

‎HDR/Bloom.shader

+223
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,223 @@
1+
Shader "Hidden/Post FX/Bloom"
2+
{
3+
Properties
4+
{
5+
_MainTex ("", 2D) = "" {}
6+
_BaseTex ("", 2D) = "" {}
7+
_AutoExposure ("", 2D) = "" {}
8+
}
9+
10+
CGINCLUDE
11+
#pragma target 3.0
12+
float4 _MainTex_ST;
13+
float4 _MainTex_TexelSize;
14+
sampler2D _MainTex;
15+
ENDCG
16+
17+
SubShader
18+
{
19+
ZTest Always Cull Off ZWrite Off
20+
21+
Pass
22+
{
23+
CGPROGRAM
24+
#pragma multi_compile __ ANTI_FLICKER
25+
#pragma multi_compile __ UNITY_COLORSPACE_GAMMA
26+
#pragma vertex SetVertexShader
27+
#pragma fragment SetPixelShader
28+
29+
sampler2D _AutoExposure;
30+
float3 _Curve;
31+
float _Threshold;
32+
float _PrefilterOffs;
33+
34+
void SetVertexShader(inout float4 vertex : POSITION, inout float2 texcoord : TEXCOORD0)
35+
{
36+
vertex = UnityObjectToClipPos(vertex);
37+
}
38+
39+
half Brightness(half3 c)
40+
{
41+
return max(c.x, max(c.y, c.z));
42+
}
43+
44+
half3 Median(half3 a, half3 b, half3 c)
45+
{
46+
return a + b + c - min(min(a, b), c) - max(max(a, b), c);
47+
}
48+
49+
half4 FetchAutoExposed(sampler2D tex, float2 uv)
50+
{
51+
float autoExposure = 1.0;
52+
autoExposure = tex2D(_AutoExposure, uv).r;
53+
return tex2D(tex, uv) * autoExposure;
54+
}
55+
56+
half4 SetPixelShader(in float4 vertex : POSITION, in float2 texcoord : TEXCOORD0) : SV_Target
57+
{
58+
float2 uv = texcoord + _MainTex_TexelSize.xy * _PrefilterOffs;
59+
#if ANTI_FLICKER
60+
float3 d = _MainTex_TexelSize.xyx * float3(1.0, 1.0, 0.0);
61+
half4 s0 = min(FetchAutoExposed(_MainTex, uv),65504.0);
62+
half3 s1 = min(FetchAutoExposed(_MainTex, uv - d.xz).rgb,65504.0);
63+
half3 s2 = min(FetchAutoExposed(_MainTex, uv + d.xz).rgb,65504.0);
64+
half3 s3 = min(FetchAutoExposed(_MainTex, uv - d.zy).rgb,65504.0);
65+
half3 s4 = min(FetchAutoExposed(_MainTex, uv + d.zy).rgb,65504.0);
66+
half3 m = Median(Median(s0.rgb, s1, s2), s3, s4);
67+
#else
68+
half4 s0 = min(FetchAutoExposed(_MainTex, uv),65504.0);
69+
half3 m = s0.rgb;
70+
#endif
71+
#if UNITY_COLORSPACE_GAMMA
72+
m = m * (m * (m * 0.305306011h + 0.682171111h) + 0.012522878h);
73+
#endif
74+
half br = Brightness(m);
75+
half rq = clamp(br - _Curve.x, 0.0, _Curve.y);
76+
rq = _Curve.z * rq * rq;
77+
m *= max(rq, br - _Threshold) / max(br, 1e-5);
78+
return half4(m,0);
79+
}
80+
81+
ENDCG
82+
}
83+
84+
Pass
85+
{
86+
CGPROGRAM
87+
#pragma multi_compile __ ANTI_FLICKER
88+
#pragma vertex SetVertexShader
89+
#pragma fragment SetPixelShader
90+
91+
half Brightness(half3 c)
92+
{
93+
return max(c.x, max(c.y, c.z));
94+
}
95+
96+
half3 DownsampleFilter(sampler2D tex, float2 uv, float2 texelSize)
97+
{
98+
float4 d = texelSize.xyxy * float4(-1.0, -1.0, 1.0, 1.0);
99+
half3 s;
100+
s = tex2D(tex, uv + d.xy).rgb;
101+
s += tex2D(tex, uv + d.zy).rgb;
102+
s += tex2D(tex, uv + d.xw).rgb;
103+
s += tex2D(tex, uv + d.zw).rgb;
104+
return s * (1.0 / 4.0);
105+
}
106+
107+
half3 DownsampleAntiFlickerFilter(sampler2D tex, float2 uv, float2 texelSize)
108+
{
109+
float4 d = texelSize.xyxy * float4(-1.0, -1.0, 1.0, 1.0);
110+
half3 s1 = tex2D(tex, uv + d.xy).rgb;
111+
half3 s2 = tex2D(tex, uv + d.zy).rgb;
112+
half3 s3 = tex2D(tex, uv + d.xw).rgb;
113+
half3 s4 = tex2D(tex, uv + d.zw).rgb;
114+
half s1w = 1.0 / (Brightness(s1) + 1.0);
115+
half s2w = 1.0 / (Brightness(s2) + 1.0);
116+
half s3w = 1.0 / (Brightness(s3) + 1.0);
117+
half s4w = 1.0 / (Brightness(s4) + 1.0);
118+
half one_div_wsum = 1.0 / (s1w + s2w + s3w + s4w);
119+
return (s1 * s1w + s2 * s2w + s3 * s3w + s4 * s4w) * one_div_wsum;
120+
}
121+
122+
void SetVertexShader(inout float4 vertex : POSITION, inout float2 texcoord : TEXCOORD0)
123+
{
124+
vertex = UnityObjectToClipPos(vertex);
125+
}
126+
127+
half4 SetPixelShader(in float4 vertex : POSITION, in float2 texcoord : TEXCOORD0) : SV_Target
128+
{
129+
#if ANTI_FLICKER
130+
return half4(DownsampleAntiFlickerFilter(_MainTex, texcoord, _MainTex_TexelSize.xy),0);
131+
#else
132+
return half4(DownsampleFilter(_MainTex, texcoord, _MainTex_TexelSize.xy),0);
133+
#endif
134+
}
135+
136+
ENDCG
137+
}
138+
139+
Pass
140+
{
141+
CGPROGRAM
142+
#pragma vertex SetVertexShader
143+
#pragma fragment SetPixelShader
144+
145+
void SetVertexShader(inout float4 vertex : POSITION, inout float2 texcoord : TEXCOORD0)
146+
{
147+
vertex = UnityObjectToClipPos(vertex);
148+
}
149+
150+
half3 DownsampleFilter(sampler2D tex, float2 uv, float2 texelSize)
151+
{
152+
float4 d = texelSize.xyxy * float4(-1.0, -1.0, 1.0, 1.0);
153+
half3 s;
154+
s = tex2D(tex, uv + d.xy).rgb;
155+
s += tex2D(tex, uv + d.zy).rgb;
156+
s += tex2D(tex, uv + d.xw).rgb;
157+
s += tex2D(tex, uv + d.zw).rgb;
158+
return s * (1.0 / 4.0);
159+
}
160+
161+
half4 SetPixelShader(in float4 vertex : POSITION, in float2 texcoord : TEXCOORD0) : SV_Target
162+
{
163+
return half4(DownsampleFilter(_MainTex, texcoord, _MainTex_TexelSize.xy),0);
164+
}
165+
166+
ENDCG
167+
}
168+
169+
Pass
170+
{
171+
CGPROGRAM
172+
#pragma vertex SetVertexShader
173+
#pragma fragment SetPixelShader
174+
175+
float _SampleScale;
176+
sampler2D _BaseTex;
177+
float2 _BaseTex_TexelSize;
178+
179+
struct SHADERDATA
180+
{
181+
float4 pos : SV_POSITION;
182+
float2 uvMain : TEXCOORD0;
183+
float2 uvBase : TEXCOORD1;
184+
};
185+
186+
half3 UpsampleFilter(sampler2D tex, float2 uv, float2 texelSize, float sampleScale)
187+
{
188+
float4 d = texelSize.xyxy * float4(1.0, 1.0, -1.0, 0.0) * sampleScale;
189+
half3 s;
190+
s = tex2D(tex, uv - d.xy).rgb;
191+
s += tex2D(tex, uv - d.wy).rgb * 2.0;
192+
s += tex2D(tex, uv - d.zy).rgb;
193+
s += tex2D(tex, uv + d.zw).rgb * 2.0;
194+
s += tex2D(tex, uv).rgb * 4.0;
195+
s += tex2D(tex, uv + d.xw).rgb * 2.0;
196+
s += tex2D(tex, uv + d.zy).rgb;
197+
s += tex2D(tex, uv + d.wy).rgb * 2.0;
198+
s += tex2D(tex, uv + d.xy).rgb;
199+
return s * (1.0 / 16.0);
200+
}
201+
202+
SHADERDATA SetVertexShader(float4 vertex : POSITION, float2 texcoord : TEXCOORD0)
203+
{
204+
SHADERDATA o;
205+
o.pos = UnityObjectToClipPos(vertex);
206+
o.uvMain = texcoord.xy;
207+
o.uvBase = o.uvMain;
208+
#if UNITY_UV_STARTS_AT_TOP
209+
if (_BaseTex_TexelSize.y < 0.0) o.uvBase.y = 1.0 - o.uvBase.y;
210+
#endif
211+
return o;
212+
}
213+
214+
half4 SetPixelShader(SHADERDATA i) : SV_Target
215+
{
216+
half3 base = tex2D(_BaseTex, i.uvBase).rgb;
217+
half3 blur = UpsampleFilter(_MainTex, i.uvMain, _MainTex_TexelSize.xy, _SampleScale);
218+
return half4(base + blur,0);
219+
}
220+
ENDCG
221+
}
222+
}
223+
}

‎HDR/EyeAdaptation.shader

+116
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,116 @@
1+
Shader "Hidden/Post FX/Eye Adaptation"
2+
{
3+
Properties
4+
{
5+
_MainTex("Texture", 2D) = "white" {}
6+
}
7+
SubShader
8+
{
9+
Cull Off ZWrite Off ZTest Always
10+
Pass
11+
{
12+
CGPROGRAM
13+
#pragma vertex SetVertexShader
14+
#pragma fragment SetPixelShader
15+
#pragma target 4.5
16+
#pragma multi_compile __ AUTO_KEY_VALUE
17+
18+
#define HISTOGRAM_BINS 64
19+
#define HISTOGRAM_TEXELS HISTOGRAM_BINS / 4
20+
#define HISTOGRAM_THREAD_X 16
21+
#define HISTOGRAM_THREAD_Y 16
22+
23+
float4 _Params;
24+
float2 _Speed;
25+
float4 _ScaleOffsetRes;
26+
float _ExposureCompensation;
27+
StructuredBuffer<uint> _Histogram;
28+
float4 _MainTex_ST;
29+
float4 _MainTex_TexelSize;
30+
sampler2D _MainTex;
31+
32+
float GetLuminanceFromHistogramBin(float bin, float2 scaleOffset)
33+
{
34+
return exp2((bin - scaleOffset.y) / scaleOffset.x);
35+
}
36+
37+
float GetBinValue(uint index, float maxHistogramValue)
38+
{
39+
return float(_Histogram[index]) * maxHistogramValue;
40+
}
41+
42+
float FindMaxHistogramValue()
43+
{
44+
uint maxValue = 0u;
45+
for (uint i = 0; i < HISTOGRAM_BINS; i++)
46+
{
47+
uint h = _Histogram[i];
48+
maxValue = max(maxValue, h);
49+
}
50+
return float(maxValue);
51+
}
52+
53+
void FilterLuminance(uint i, float maxHistogramValue, inout float4 filter)
54+
{
55+
float binValue = GetBinValue(i, maxHistogramValue);
56+
float offset = min(filter.z, binValue);
57+
binValue -= offset;
58+
filter.zw -= offset.xx;
59+
binValue = min(filter.w, binValue);
60+
filter.w -= binValue;
61+
float luminance = GetLuminanceFromHistogramBin(float(i) / float(HISTOGRAM_BINS), _ScaleOffsetRes.xy);
62+
filter.xy += float2(luminance * binValue, binValue);
63+
}
64+
65+
float GetAverageLuminance(float maxHistogramValue)
66+
{
67+
uint i;
68+
float totalSum = 0.0;
69+
[loop]
70+
for (i = 0; i < HISTOGRAM_BINS; i++) totalSum += GetBinValue(i, maxHistogramValue);
71+
float4 filter = float4(0.0, 0.0, totalSum * _Params.xy);
72+
[loop]
73+
for (i = 0; i < HISTOGRAM_BINS; i++) FilterLuminance(i, maxHistogramValue, filter);
74+
return clamp(filter.x / max(filter.y, 1.0e-4), _Params.z, _Params.w);
75+
}
76+
77+
float GetExposureMultiplier(float avgLuminance)
78+
{
79+
avgLuminance = max(1.0e-4, avgLuminance);
80+
#if AUTO_KEY_VALUE
81+
half keyValue = 1.03 - (2.0 / (2.0 + log2(avgLuminance + 1.0)));
82+
#else
83+
half keyValue = _ExposureCompensation;
84+
#endif
85+
half exposure = keyValue / avgLuminance;
86+
return exposure;
87+
}
88+
89+
float InterpolateExposure(float newExposure, float oldExposure)
90+
{
91+
float delta = newExposure - oldExposure;
92+
float speed = delta > 0.0 ? _Speed.x : _Speed.y;
93+
float exposure = oldExposure + delta * (1.0 - exp2(-unity_DeltaTime.x * speed));
94+
return exposure;
95+
}
96+
97+
void SetVertexShader(inout float4 vertex : POSITION, inout float2 texcoord : TEXCOORD0)
98+
{
99+
vertex = UnityObjectToClipPos(vertex);
100+
}
101+
102+
float4 SetPixelShader(float4 vertex : POSITION, float2 texcoord : TEXCOORD0) : SV_Target
103+
{
104+
float maxValue = 1.0 / FindMaxHistogramValue();
105+
float avgLuminance = GetAverageLuminance(maxValue);
106+
float exposure = GetExposureMultiplier(avgLuminance);
107+
float prevExposure = tex2D(_MainTex, (0.5).xx);
108+
exposure = InterpolateExposure(exposure, prevExposure);
109+
return exposure.xxxx;
110+
}
111+
112+
ENDCG
113+
}
114+
115+
}
116+
}

‎HDR/EyeHistogram.compute

+29
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,29 @@
1+
#define HISTOGRAM_BINS 64
2+
#define HISTOGRAM_TEXELS HISTOGRAM_BINS / 4
3+
#define HISTOGRAM_THREAD_X 16
4+
#define HISTOGRAM_THREAD_Y 16
5+
6+
RWStructuredBuffer<uint> _Histogram;
7+
Texture2D<float4> _Source;
8+
float4 _ScaleOffsetRes;
9+
groupshared uint gs_histogram[HISTOGRAM_BINS];
10+
11+
#pragma kernel KEyeHistogram
12+
[numthreads(HISTOGRAM_THREAD_X,HISTOGRAM_THREAD_Y,1)]
13+
void KEyeHistogram(uint2 dispatchThreadId : SV_DispatchThreadID, uint2 groupThreadId : SV_GroupThreadID)
14+
{
15+
const uint localThreadId = groupThreadId.y * HISTOGRAM_THREAD_X + groupThreadId.x;
16+
if (localThreadId < HISTOGRAM_BINS) gs_histogram[localThreadId] = 0u;
17+
GroupMemoryBarrierWithGroupSync();
18+
if (dispatchThreadId.x < (uint)_ScaleOffsetRes.z && dispatchThreadId.y < (uint)_ScaleOffsetRes.w)
19+
{
20+
uint weight = 1u;
21+
float3 color = _Source[dispatchThreadId].xyz;
22+
float luminance = max(color.x, max(color.y, color.z));
23+
float logLuminance = saturate(log2(luminance) * _ScaleOffsetRes.x + _ScaleOffsetRes.y);
24+
uint idx = (uint)(logLuminance * (HISTOGRAM_BINS - 1u));
25+
InterlockedAdd(gs_histogram[idx], weight);
26+
}
27+
GroupMemoryBarrierWithGroupSync();
28+
if (localThreadId < HISTOGRAM_BINS) InterlockedAdd(_Histogram[localThreadId], gs_histogram[localThreadId]);
29+
}

0 commit comments

Comments
 (0)