Use gradient noise for blur

papadanku · Oct 1, 2023 · b5468ca · b5468ca
1 parent 45853bd
commit b5468ca
Show file tree

Hide file tree

Showing 3 changed files with 33 additions and 6 deletions.
diff --git a/shaders/cMotionBlur.fx b/shaders/cMotionBlur.fx
@@ -146,7 +146,7 @@ namespace cMotionBlur
         [unroll]
         for (int k = 0; k < Samples; ++k)
         {
-            float Random = (GetGradientNoise(Input.HPos.xy + k) * 2.0) - 1.0;
+            float Random = (GetIGNoise(Input.HPos.xy + k) * 2.0) - 1.0;
             float2 RandomTex = Input.Tex0.xy + (ScaledVelocity * Random);
             OutputColor += tex2D(CShade_SampleColorTex, RandomTex);
         }

diff --git a/shaders/cNoiseBlur.fx b/shaders/cNoiseBlur.fx
@@ -9,8 +9,8 @@ uniform float _Radius <
     ui_label = "Radius";
     ui_type = "slider";
     ui_min = 0.0;
-    ui_max = 64.0;
-> = 32.0;
+    ui_max = 1.0;
+> = 0.5;
 
 
 /*
@@ -24,7 +24,7 @@ float4 PS_NoiseBlur(VS2PS_Quad Input) : SV_TARGET0
     const float Pi2 = acos(-1.0) * 2.0;
     const float2 ScreenSize = int2(BUFFER_WIDTH, BUFFER_HEIGHT);
     const float2 PixelSize = 1.0 / ScreenSize;
-    float Noise = Pi2 * GetValueNoise(Input.Tex0.xy * 256.0);
+    float Noise = Pi2 * GetGradientNoise(Input.Tex0.xy * 256.0);
 
     float2 Rotation = 0.0;
     sincos(Noise, Rotation.y, Rotation.x);

diff --git a/shaders/shared/cImageProcessing.fxh b/shaders/shared/cImageProcessing.fxh
@@ -162,14 +162,14 @@
         http://www.iryoku.com/downloads/Next-Generation-Post-Processing-in-Call-of-Duty-Advanced-Warfare-v18.pptx
     */
 
-    float GetGradientNoise(float2 Position)
+    float GetIGNoise(float2 Position)
     {
         return frac(52.9829189 * frac(dot(Position, float2(0.06711056, 0.00583715))));
     }
 
     float3 GetDither(float2 Position)
     {
-        return GetGradientNoise(Position) / 255.0;
+        return GetIGNoise(Position) / 255.0;
     }
 
     /*
@@ -189,6 +189,7 @@
     }
 
     /*
+        GetGradientNoise(): https://iquilezles.org/articles/gradientnoise/
         GetQuintic(): https://iquilezles.org/articles/texture/
 
         The MIT License (MIT)
@@ -230,6 +231,32 @@
         return lerp(lerp(A, B, UV.x), lerp(C, D, UV.x), UV.y);
     }
 
+    float GetGradient(float2 I, float2 F, float2 O)
+    {
+        // Get constants
+        const float TwoPi = acos(-1.0) * 2.0;
+
+        // Calculate random hash rotation
+        float Hash = GetHash(I + O) * TwoPi;
+        float2 HashSinCos = float2(sin(Hash), cos(Hash));
+
+        // Calculate final dot-product
+        return dot(HashSinCos, F - O);
+    }
+
+    float GetGradientNoise(float2 Tex)
+    {
+        float2 I = floor(Tex);
+        float2 F = frac(Tex);
+        float A = GetGradient(I, F, float2(0.0, 0.0));
+        float B = GetGradient(I, F, float2(1.0, 0.0));
+        float C = GetGradient(I, F, float2(0.0, 1.0));
+        float D = GetGradient(I, F, float2(1.0, 1.0));
+        float2 UV = GetQuintic(F);
+        float Noise = lerp(lerp(A, B, UV.x), lerp(C, D, UV.x), UV.y);
+        return saturate((Noise * 0.5) + 0.5);
+    }
+
     /*
         [Color Processing]
     */