Changeset 2999 for GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/ssao.cg

Timestamp:

10/03/08 14:35:07 (16 years ago)

Author:

mattausch

Message:

trying to use smaller fbo

File:

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

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

@@ -48 +48 @@
                                                                                 float3 bl, float3 br, float3 tl, float3 tr)
 {
-#if 0
+#if 1
         float eyeSpaceDepth = tex2Dlod(colors, float4(texcoord, 0, SSAO_MIPMAP_LEVEL)).w;
-        float3 rotView = normalize(Interpol(texcoord, bl, br, tl, tr));
-        
-        float3 sample_position = eyePos - rotView * eyeSpaceDepth;
+        //float3 rotView = normalize(Interpol(texcoord, bl, br, tl, tr));
+        float3 rotView = Interpol(texcoord, bl, br, tl, tr);
+        
+        float3 samplePos = eyePos - rotView * eyeSpaceDepth;
 #else
-        float3 sample_position = tex2Dlod(colors, float4(texcoord, 0, SSAO_MIPMAP_LEVEL)).xyz;
-#endif
-        return sample_position;
+        float3 samplePos = tex2Dlod(colors, float4(texcoord, 0, SSAO_MIPMAP_LEVEL)).xyz;
+#endif
+        return samplePos;
 }
 
@@ -101 +102 @@
                 float2 texcoord = IN.texCoord.xy + offsetTransformed * AREA_SIZE * scaleFactor;
 
-                if ((texcoord.x <= 1.0f) && (texcoord.x >= 0.0f) && (texcoord.y <= 1.0f) && (texcoord.y >= 0.0f))
-                        ++ numSamples;
-
-                float3 sample_position = ReconstructSamplePosition(eyePos, colors, texcoord, bl, br, tl, tr);
-
-                float3 vector_to_sample = sample_position - centerPosition.xyz;
-                const float length_to_sample = length(vector_to_sample);
-
-                float3 direction_to_sample = vector_to_sample / length_to_sample;
+                //if ((texcoord.x <= 1.0f) && (texcoord.x >= 0.0f) && (texcoord.y <= 1.0f) && (texcoord.y >= 0.0f))++ numSamples;
+
+                // get sample world space position
+                float eyeSpaceDepth = tex2Dlod(colors, float4(texcoord, 0, SSAO_MIPMAP_LEVEL)).w;
+                //float3 rotView = normalize(Interpol(texcoord, bl, br, tl, tr));
+                float3 rotView = Interpol(texcoord, bl, br, tl, tr);
+        
+                float3 samplePos = ReconstructSamplePosition(eyePos, colors, texcoord, bl, br, tl, tr);
+
+
+                ///////
+                //-- compute contribution of current sample taking into account direction and angle
+
+                float3 dirSample = samplePos - centerPosition.xyz;
+                const float lengthSample = length(dirSample);
+
+                float3 nDirSample = dirSample / lengthSample;
 
                 // angle between current normal and direction to sample controls AO intensity.
-                const float cos_angle = max(dot(direction_to_sample, currentNormal), 0.0f);
+                const float cos_angle = max(dot(nDirSample, currentNormal), 0.0f);
 
                 // the distance_scale offset is used to avoid singularity that occurs at global illumination when 
                 // the distance to a sample approaches zero
-                const float distance_intensity = 
-                        (SAMPLE_INTENSITY * DISTANCE_SCALE) / (DISTANCE_SCALE + length_to_sample * length_to_sample);
+                const float intensity = 
+                        (SAMPLE_INTENSITY * DISTANCE_SCALE) / (DISTANCE_SCALE + lengthSample * lengthSample);
 
 #if 0
                 // 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 view_correction = 1.0f + VIEW_CORRECTION_SCALE * (1.0f - dot(currentViewDir, currentNormal));
-                total_ao += cos_angle * distance_intensity * view_correction;
-#endif
-                total_ao += cos_angle * distance_intensity;
+                const float viewCorrection = 1.0f + VIEW_CORRECTION_SCALE * (1.0f - dot(currentViewDir, currentNormal));
+                total_ao += cos_angle * intensity * viewCorrection;
+#endif
+                total_ao += cos_angle * intensity;
         }
 
         return float2(max(0.0f, 1.0f - total_ao), numSamples);
-        //return saturate(dot(currentViewDir, currentNormal));
 }
 
@@ -165 +173 @@
         const float4 centerPosition = tex2D(positions, IN.texCoord.xy);
 
-#if 1   
+#if 0   
         const float2 ao = ssao(IN, positions, noiseTexture, samples, normal, centerPosition, w, eyePos, bl, br, tl, tr);
 
@@ -197 +205 @@
         float4 oldPos = mul(oldModelViewProj, realPos);
 
+        const float4 projPos = oldPos / oldPos.w;
+
         // the current depth projected into the old frame
-        const float projDepth = oldPos.z / oldPos.w;
+        const float projDepth = projPos.z;
 
         // fit from unit cube into 0 .. 1
-        float2 tex = (oldPos.xy / oldPos.w) * 0.5f + 0.5f;
+        float2 tex = (projPos.xy) * 0.5f + 0.5f;
 
         // optain the sample from the last frame
@@ -212 +222 @@
         const float depthDif = 1.0f - projDepth / oldDepth;
 
-
         float newWeight;
 
         // the number of valid samples in this frame
-        const float newNumSamples = ao.y;
+        //const float newNumSamples = ao.y;
 
 
@@ -224 +233 @@
                 (abs(depthDif) < 1e-4f) 
                 // if visibility changed in the surrounding area we have to recompute
-                && (oldNumSamples > 0.8f * newNumSamples)
+                //&& (oldNumSamples > 0.8f * newNumSamples)
                 )
         {