Changeset 3198 for GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/combineSsao.cg

Timestamp:

11/30/08 20:41:23 (16 years ago)

Author:

mattausch

Message:

removed some visual bugs (trees against sky), flickering much better now

File:

• GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/combineSsao.cg (modified) (7 diffs)

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

@@ -122 +122 @@
         for (int i = 0; i < NUM_SSAO_FILTER_SAMPLES; ++ i)
         {
-                sampleTexCoord = float4(texCoord + filterOffs[i] * scale, 0, 0);
+                sampleTexCoord = float4(texCoord + filterOffs[i] * scale, .0f, .0f);
 
                 aoSample = tex2Dlod(ssaoTex, sampleTexCoord);
@@ -128 +128 @@
 
                 // check spatial discontinuity
-                // using the depth from the color texture is not 100% correct as depth was
+
+                // note: using the depth from the color texture is not 100% correct as depth was
                 // not scaled with the interpolated view vector depth yet ...
                 samplePos = ReconstructSamplePos(colorsTex, sampleTexCoord.xy, bl, br, tl, tr);
@@ -134 +135 @@
 
                 len = min(SqrLen(centerPos - samplePos), 1e2f);
-
                 spatialFactor = 1.0f / max(len, 1e-3f);
 
                 //normalFactor = max(step(.0f, dot(sampleNorm, centerNormal)), 1e-2f);
-                //normalFactor = max(dot(sampleNorm, samplePos), 1e-3f);
                 convergenceFactor = aoSample.y + 1.0f;
-                //convergenceFactor = max(step(0.5f + NUM_SAMPLES, aoSample.y), 1e-2f);
-                //convergenceFactor = aoSample.y;
-
+                
                 // combine the weights
                 w = convergenceFactor * convergenceFactor * spatialFactor;// * normalFactor;
-                //w = spatialFactor * normalFactor;
-
+                
                 average += aoSample.x * w;
                 total_w += w;
@@ -178 +174 @@
         float4 ao = tex2Dlod(ssaoTex, float4(IN.texCoord, 0, 0));
 
-        float4 dummy;
-        //const float xoffs = .5f / 1024.0f;    const float yoffs = .5f / 768.0f;
-        const float xoffs = 1.0f / 1024.0f;     const float yoffs = 1.0f / 768.0f;
-
-        dummy.x = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(xoffs, yoffs), 0, 0)).w;
-        dummy.y = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(xoffs, -yoffs), 0, 0)).w;
-        dummy.z = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(-xoffs, yoffs), 0, 0)).w;
-        dummy.w = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(-yoffs, -yoffs), 0, 0)).w;
-
-        /*dummy.x = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(xoffs, 0), 0, 0)).y;
-        dummy.y = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(0, yoffs), 0, 0)).y;
-        dummy.z = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(-xoffs, 0), 0, 0)).y;
-        dummy.w = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(0, -yoffs), 0, 0)).y;
-*/
-        const float convergence = min(min(dummy.x, dummy.y), min(dummy.z, dummy.w));
-        //const float convergence = max(max(dummy.x, dummy.y), max(dummy.z, dummy.w));
+        // 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 w = 512.0f; const float h = 384.0f;
+        const float xoffs = .5f / w; const float yoffs = .5f / h;
+
+        // get position exactly between old texel centers
+        float2 center;
+        center.x = float(floor(IN.texCoord.x * w - .5f) + 1.0f) / w;
+        center.y = float(floor(IN.texCoord.y * h - .5f) + 1.0f) / h;
+
+        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 convergence = min(m1, m2);
         //const float convergence = ao.y;
 
@@ -201 +202 @@
         // filter up to a certain convergance value and leave out background (sky) by checking depth
         if ((convergence < thres) && (col.w < 1e10f))
-        //if (col.w < 1e10f)
         {
-                //const float eyeSpaceDepth = col.w; const float distanceScaleWeight = 2.0f;
-                //const float distanceScale = distanceScaleWeight / (eyeSpaceDepth + distanceScaleWeight);
                 const float distanceScale = 1.0f;
 
                 const float convergenceWeight = thres / (SSAO_FILTER_WIDTH - 1.0f);
                 const float convergenceScale = convergenceWeight / (convergence + convergenceWeight);
-
                 const float scale = SSAO_FILTER_WIDTH * convergenceScale * distanceScale;
 
                 // the filtered ssao value
-                //ao.x = DiscontinuityFilter2(IN.texCoord, ao, col, ssaoTex, normalsTex, colorsTex, filterOffs, scale, bl, br, tl, tr);
+                ao.x = DiscontinuityFilter2(IN.texCoord, ao, col, ssaoTex, normalsTex, colorsTex, filterOffs, scale, bl, br, tl, tr);
         }
 
@@ -221 +218 @@
                 OUT.illum_col.xyz = col.xyz;
 
-        //OUT.illum_col.xyz = float3(0, clamp(1.0f - ao.y * 1e-3f, 0, 1), 1);
-        //const float mydummy = ao.w * 1e-3f;
-        OUT.illum_col.xyz = float3(ao.x, ao.x, ao.x);
+        //OUT.illum_col.xyz = float3(ao.x, ao.x, step(thres, convergence));
+        //OUT.illum_col.xyz = float3(ao.x, ao.x, ao.x);
         //OUT.illum_col.xyz = float3(0, clamp(1.0f - ao.y * 1e-3f, 0, 1), 1);
         //OUT.illum_col.xyz = float3(0, 1.0f - step(0.5f + NUM_SAMPLES, convergence), 1);
@@ -230 +226 @@
         return OUT;
 }
+
+
+
+/** Function combining image and indirect illumination buffer using a 
+        depth and normal aware discontinuity filter.
+*/
+pixel SmoothSsao(fragment IN, 
+                                 uniform sampler2D ssaoTex)
+{
+        pixel OUT;
+
+        float4 ao = tex2Dlod(ssaoTex, float4(IN.texCoord, 0, 0));
+
+        float4 dummy;
+        const float xoffs = .5f / 1024.0f; const float yoffs = .5f / 768.0f;
+
+        // get positions exactly between old texel centers
+        dummy.x = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(xoffs, 0), 0, 0)).y;
+        dummy.y = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(0, -yoffs), 0, 0)).y;
+        dummy.z = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(-xoffs, 0), 0, 0)).y;
+        dummy.w = tex2Dlod(ssaoTex, float4(IN.texCoord + float2(0, yoffs), 0, 0)).y;
+
+        const float m1 = min(dummy.x, dummy.y);
+        const float m2 = min(dummy.z, dummy.w);
+
+        ao.y = min(ao.y, min(m1, m2));
+
+        return OUT;
+}