Changeset 3150

Timestamp:

11/20/08 13:44:57 (16 years ago)

Author:

mattausch

Message:

cleaned up ssao code, removed fixed kernel + jitter and rotation stuff because not working properly

Location:

GTP/trunk/App/Demos/Vis/FriendlyCulling/src

Files:

• DeferredRenderer.cpp (modified) (3 diffs)
• shaders/ssao.cg (modified) (10 diffs)

GTP/trunk/App/Demos/Vis/FriendlyCulling/src/DeferredRenderer.cpp

@@ -325 +325 @@
 
         // create noise texture for ssao
-        CreateNoiseTex2D(mIllumFbo->GetWidth(), mIllumFbo->GetHeight());
-        //CreateNoiseTex2D(mIllumFbo->GetWidth() / 4, mIllumFbo->GetWidth() / 4);
-        CreateNoiseTex1D(mWidth / 8);
+        // for performance reasons we use a smaller texture and repeat it over the screen
+        CreateNoiseTex2D(mIllumFbo->GetWidth() / 4, mIllumFbo->GetWidth() / 4);
+        //CreateNoiseTex1D(mIllumFbo->GetWidth() / 4);
 
         mProjViewMatrix = IdentityMatrix();
@@ -382 +382 @@
                  "samples", "bl", "br", "tl", "tr", 
                  "modelViewProj", "oldModelViewProj", "oldEyePos", "oldbl", "oldbr", 
-                 "oldtl", "oldtr", "attribsTex", "noiseTex1D"};
-        sCgSsaoProgram->AddParameters(ssaoParams, 0, 19);
+                 "oldtl", "oldtr", "attribsTex"};
+        sCgSsaoProgram->AddParameters(ssaoParams, 0, 18);
         
         string giParams[] = 
@@ -632 +632 @@
         sCgSsaoProgram->SetTexture(i ++, attribsTex);
 
-        sCgSsaoProgram->SetTexture(i ++, noiseTex1D);
 
         DrawQuad(sCgSsaoProgram);

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

@@ -246 +246 @@
 /** The ssao shader returning the an intensity value between 0 and 1
 */
+float2 ssao2(fragment IN,
+                         sampler2D colors,
+                         sampler2D noiseTex,
+                         float2 samples[NUM_SAMPLES],
+                         float3 normal,
+                         float3 centerPosition,
+                         float scaleFactor,
+                         float3 bl,
+                         float3 br,
+                         float3 tl,
+                         float3 tr, 
+                         float3 viewDir,
+                         sampler2D normalTex
+                         )
+{
+        // Check in a circular area around the current position.
+        // Shoot vectors to the positions there, and check the angle to these positions.
+        // Summing up these angles gives an estimation of the occlusion at the current position.
+
+        float total_ao = .0f;
+        float numSamples = .0f;
+
+        for (int i = 0; i < NUM_SAMPLES; ++ i) 
+        {
+                const float2 offset = samples[i];
+
+#if 1
+                ////////////////////
+                //-- add random noise: reflect around random normal vector (rather slow!)
+
+                const float2 mynoise = tex2Dlod(noiseTex, float4(IN.texCoord * 4.0f, 0, 0)).xy;
+                const float2 offsetTransformed = myreflect(offset, mynoise);
+#else
+                const float2 offsetTransformed = offset;
+#endif
+                // weight with projected coordinate to reach similar kernel size for near and far
+                //const float2 texcoord = IN.texCoord.xy + offsetTransformed * scaleFactor + jitter;
+                const float2 texcoord = IN.texCoord.xy + offsetTransformed * scaleFactor;
+
+                //if ((texcoord.x <= 1.0f) && (texcoord.x >= 0.0f) && (texcoord.y <= 1.0f) && (texcoord.y >= 0.0f)) ++ numSamples;
+                const float3 samplePos = ReconstructSamplePos(colors, texcoord, bl, br, tl, tr);
+                const float3 sampleNormal = normalize(tex2Dlod(normalTex, float4(IN.texCoord * 4.0f, 0, 0)).xyz);
+
+
+                ////////////////
+                //-- compute contribution of sample using the direction and angle
+
+                float3 dirSample = samplePos - centerPosition;
+                const float lengthToSample = max(length(dirSample), 1e-6f);
+
+                dirSample /= lengthToSample; // normalize
+
+                // angle between current normal and direction to sample controls AO intensity.
+                float cosAngle = max(dot(sampleNormal, normal), .0f);
+        
+                // the distance_scale offset is used to avoid singularity that occurs at global illumination when 
+                // the distance to a sample approaches zero
+                const float aoContrib = SAMPLE_INTENSITY / (DISTANCE_SCALE + lengthToSample * lengthToSample);
+                //const float aoContrib = (1.0f > lengthToSample) ? occlusionPower(9e-2f, DISTANCE_SCALE + lengthToSample): .0f;
+
+#if 1
+                // if surface normal perpenticular to view dir, approx. half of the samples will not count
+                // => compensate for this (on the other hand, projected sampling area could be larger!)
+
+                const float viewCorrection = 1.0f + VIEW_CORRECTION_SCALE * max(dot(viewDir, normal), 0.0f);
+                total_ao += cosAngle * aoContrib * viewCorrection;
+#else
+                total_ao += cosAngle * aoContrib;
+#endif
+        }
+
+        return float2(max(0.0f, 1.0f - total_ao), numSamples);
+}
+
+
+/** The ssao shader returning the an intensity value between 0 and 1
+*/
 float2 ssao(fragment IN,
                         sampler2D colors,
@@ -258 +335 @@
                         float3 tr, 
                         float3 viewDir
-                        , float2 noiseOffs
-                        , sampler2D noiseTex1D
                         )
 {
@@ -269 +344 @@
         float numSamples = .0f;
 
-
-        //float2 jitter = tex2Dlod(noiseTex1D, float4(IN.texCoord.x * 4.0f + noiseOffs.x, 0.5f, 0, 0)).xy;
-        //float2 jitter = tex2Dlod(noiseTex1D, float4(noiseOffs.x, 0.5f, 0, 0)).xy;
-
         for (int i = 0; i < NUM_SAMPLES; ++ i) 
         {
@@ -281 +352 @@
                 //-- add random noise: reflect around random normal vector (rather slow!)
 
-                //float2 mynoise = tex2Dlod(noiseTex, float4(IN.texCoord * 4.0f + noiseOffs, 0, 0)).xy;
-                float2 mynoise = tex2Dlod(noiseTex, float4(IN.texCoord, .0f, .0f)).xy;
-                //float2 mynoise = tex2Dlod(noiseTex, float4(IN.texCoord * 4.0f, 0, 0)).xy;
+                float2 mynoise = tex2Dlod(noiseTex, float4(IN.texCoord * 4.0f, 0, 0)).xy;
                 const float2 offsetTransformed = myreflect(offset, mynoise);
 #else
@@ -294 +363 @@
                 //if ((texcoord.x <= 1.0f) && (texcoord.x >= 0.0f) && (texcoord.y <= 1.0f) && (texcoord.y >= 0.0f)) ++ numSamples;
                 const float3 samplePos = ReconstructSamplePos(colors, texcoord, bl, br, tl, tr);
-
+                
 
                 ////////////////
@@ -325 +394 @@
         return float2(max(0.0f, 1.0f - total_ao), numSamples);
 }
+
 
 
@@ -347 +417 @@
                    uniform float3 oldtl,
                    uniform float3 oldtr,
-                   uniform sampler2D attribsTex,
-                   uniform sampler2D noiseTex1D
+                   uniform sampler2D attribsTex
                    )
 {
@@ -360 +429 @@
         const float4 eyeSpacePos = float4(-viewDir * eyeSpaceDepth, 1.0f);
 
-        /*const float xoffs = 2.0f / 1024.0f;
-        const float yoffs = 2.0f / 768.0f;
-
-        //float3 id = tex2Dlod(attribsTex, float4(IN.texCoord, 0, 0)).xyz;
-        float3 x1 = tex2Dlod(attribsTex, float4(IN.texCoord, 0, 0)).xyz;
-        float3 x2 = tex2Dlod(attribsTex, float4(IN.texCoord + float2(xoffs, 0), 0, 0)).xyz;
-        float3 x3 = tex2Dlod(attribsTex, float4(IN.texCoord + float2(0, yoffs), 0, 0)).xyz;
-        float3 x4 = tex2Dlod(attribsTex, float4(IN.texCoord + float2(-xoffs, 0), 0, 0)).xyz;
-        float3 x5 = tex2Dlod(attribsTex, float4(IN.texCoord + float2(0, -yoffs), 0, 0)).xyz;
-
-        float3 diffVec = (x1+x2+x3+x4+x5) * .25f;
-*/
         float3 diffVec = tex2Dlod(attribsTex, float4(IN.texCoord, 0, 0)).xyz;
         
@@ -401 +458 @@
 
         const float oldSsao = temporalVals.x;
-        //const float newWeight = clamp(temporalVals.y, 1.0f, temporalCoherence);
         const float newWeight = temporalVals.y;
-
-        //float2 noiseOffs = float2((temporalVals.y - 1)/ 139.0f, .0f);
-        float2 noiseOffs = float2(.0f);
 
         float2 ao;
@@ -413 +466 @@
         {
                 ao = ssao(IN, colors, noiseTex, samples, normal, 
-                          eyeSpacePos.xyz, scaleFactor, bl, br, tl, tr, normalize(viewDir), noiseOffs, noiseTex1D);
+                          eyeSpacePos.xyz, scaleFactor, bl, br, tl, tr, normalize(viewDir));
         }
         else