Changeset 3305 for GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/combineSsaoSep.cg

Timestamp:

02/12/09 14:38:14 (15 years ago)

Author:

mattausch

Message:

removed filter radius

File:

• GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/combineSsaoSep.cg (modified) (6 diffs)

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/combineSsaoSep.cg

@@ -19 +19 @@
         float4 illum_col: COLOR0;
 };
+
+
+float ComputeConvergenceHalfRes(uniform sampler2D ssaoTex,
+                                                                float2 texCoord, 
+                                                                float2 halfres)
+{
+    // the following has to be done for half resolution ssao:
+        // get the minimum convergence by exactly sampling the 4 surrounding
+        // texels in the old texture, otherwise flickering because convergence
+        // will be interpolated when upsampling and filter size does not match!
+
+        float4 texelCenterConv;
+        const float xoffs = .5f / halfres.x; const float yoffs = .5f / halfres.y;
+
+        // get position exactly between old texel centers
+        float2 center;
+        center.x = (floor(texCoord.x * halfres.x - .5f) + 1.0f) / halfres.x;
+        center.y = (floor(texCoord.y * halfres.y - .5f) + 1.0f) / halfres.y;
+
+        texelCenterConv.x = tex2Dlod(ssaoTex, float4(center + float2( xoffs,  yoffs), 0, 0)).y;
+        texelCenterConv.y = tex2Dlod(ssaoTex, float4(center + float2( xoffs, -yoffs), 0, 0)).y;
+        texelCenterConv.z = tex2Dlod(ssaoTex, float4(center + float2(-xoffs, -yoffs), 0, 0)).y;
+        texelCenterConv.w = tex2Dlod(ssaoTex, float4(center + float2(-xoffs,  yoffs), 0, 0)).y;
+
+        const float m1 = min(texelCenterConv.x, texelCenterConv.y);
+        const float m2 = min(texelCenterConv.z, texelCenterConv.w);
+
+        const float minConvergence = min(m1, m2);
+        return minConvergence;
+}
 
 
@@ -45 +75 @@
         // combine the weights
         float w = convergenceFactor * convergenceFactor * spatialFactor;// * normalFactor;
-
         float average = aoSample.x * w;
 
@@ -94 +123 @@
                                                 uniform float3 tl,
                                                 uniform float3 tr,
-                                                uniform float2 xyStep
-                                                 )
+                                                uniform float2 res
+                                                )
 {
         pixel OUT;
@@ -108 +137 @@
         // afterwards we do not use the filter anymore
 
+        float2 xyStep = float2(1.0f / res.x, 0);
+
         // filter up to a certain convergance value and leave out background (sky) by checking depth
         if ((convergence < SSAO_CONVERGENCE_THRESHOLD) && (depth < DEPTH_THRESHOLD))
@@ -118 +149 @@
 }
 
+/** In between step that only filters in one direction
+*/
+pixel FilterSsaoHalfRes(fragment IN, 
+                                                uniform sampler2D colorsTex,
+                                                uniform sampler2D ssaoTex,
+                                                uniform float3 bl,
+                                                uniform float3 br,
+                                                uniform float3 tl,
+                                                uniform float3 tr,
+                                                uniform float2 res
+                                                 )
+{
+        pixel OUT;
+
+        const float depth = tex2Dlod(colorsTex, float4(IN.texCoord, 0, 0)).w;
+
+        OUT.illum_col = tex2Dlod(ssaoTex, float4(IN.texCoord, 0, 0));
+        // just take unfiltered convergence in current pixel
+        const float convergence = ComputeConvergenceHalfRes(ssaoTex, IN.texCoord, res * 0.5f);
+
+        const float2 xyStep = float2(1.0f / res.x, 0);
+
+        // filter reaches size 1 pixel when sample size reaches threshold 
+        // afterwards we do not use the filter anymore
+
+        // filter up to a certain convergance value and leave out background (sky) by checking depth
+        if ((convergence < SSAO_CONVERGENCE_THRESHOLD) && (depth < DEPTH_THRESHOLD))
+        {
+                // the filtered ssao value
+                OUT.illum_col.x = FilterXY(IN.texCoord, ssaoTex, colorsTex, bl, br, tl, tr, xyStep, convergence);
+        }
+
+        return OUT;
+}
 
 /** Function combining image and indirect illumination buffer using a 
     depth and convergence aware discontinuity filter.
 */
-pixel CombineSsaoFullRes(fragment IN, 
-                                                 uniform sampler2D colorsTex,
-                                                 uniform sampler2D ssaoTex,
-                                                 uniform float3 bl,
-                                                 uniform float3 br,
-                                                 uniform float3 tl,
-                                                 uniform float3 tr,
-                                                 uniform float2 xyStep
-                                                 )
+pixel CombineSsao(fragment IN, 
+                                  uniform sampler2D colorsTex,
+                                  uniform sampler2D ssaoTex,
+                                  uniform float3 bl,
+                                  uniform float3 br,
+                                  uniform float3 tl,
+                                  uniform float3 tr,
+                                  uniform float2 res
+                                  )
 {
         pixel OUT;
@@ -141 +206 @@
         const float convergence = ao.y;
 
+        const float2 xyStep = float2(0, 1.0f / res.y);
+        
         // filter reaches size 1 pixel when sample size reaches threshold 
         // afterwards we do not use the filter anymore