Changeset 2873 for GTP/trunk/App/Demos/Vis/FriendlyCulling/src/shaders/ssao.cg

Timestamp:

08/27/08 15:09:04 (16 years ago)

Author:

mattausch

Message:

 

File:

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

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

@@ -3 +3 @@
 // based on shader of Alexander Kusternig
 
-//#define NUM_SAMPLES 8
-#define NUM_SAMPLES 16
+#define NUM_SAMPLES 10
+//#define NUM_SAMPLES 16
 
 // rule of thumb: approx 1 / NUM_SAMPLES
-#define SAMPLE_INTENSITY 0.15
-//#define SAMPLE_INTENSITY 0.125f
+//#define SAMPLE_INTENSITY 0.15f
+#define SAMPLE_INTENSITY 0.2f
 
 #define AREA_SIZE 7e-1f
@@ -43 +43 @@
 
 
-/*float2 rotate(float2 pt, float2 n)
-{
-        float2 ptTransformed;
-        ptTransformed.x = n.r * pt.x - n.g * pt.y;
-        ptTransformed.y = n.g * pt.x + n.r * pt.y;
-
-        return ptTransformed;
-}*/
-
 
 /** The ssao shader returning the an intensity value between 0 and 1
@@ -74 +65 @@
         float total_ao = 0.0;
 
-        const float areaSize = 5e-1f;
-
         for (int i = 0; i < NUM_SAMPLES; i ++) 
         {
                 float2 offset = samples[i];
 
-                //sample noisetex; r stores costheta, g stores sintheta
+                ////////////////////
+                // add random noise: r stores costheta, g stores sintheta
+
                 //float2 mynoise = tex2D(noiseTexture, IN.texCoord.xy * noiseMultiplier).xy * 2.0f - 1.0f;
                 float2 mynoise = tex2D(noiseTexture, IN.texCoord.xy * noiseMultiplier).xy;
 
-                // rotation
-                //float2 offsetTransformed = offset;
-                //float2 offsetTransformed = rotate(offset, mynoise);
                 float2 offsetTransformed = reflect(offset, mynoise);
 
@@ -117 +105 @@
         return max(0.0f, 1.0f - total_ao);
         //return dot(currentViewDir, currentNormal);
-}
-
-
-/** Computes ambient occlusion + diffuse reflections
-*/
-float4 globIllum(fragment IN,
-                                 uniform sampler2D colors,
-                                 uniform sampler2D positions,
-                                 uniform sampler2D noiseTexture,
-                                 uniform float2 samples[NUM_SAMPLES],
-                                 uniform float3 currentNormal,
-                                 uniform float3 currentViewDir,
-                                 uniform float noiseMultiplier,
-                                 uniform float4 centerPosition
-                                 )
-{
-        // the w coordinate from the persp. projection
-        float w = centerPosition.w;
-
-        // 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.
-
-        // ao is in stored in the w
-        float4 total_color = float4(0, 0, 0, 1);
-
-        const float areaSize = 5e-1f;
-
-        for (int i = 0; i < NUM_SAMPLES; i ++) 
-        {
-                float2 offset = samples[i];
-
-                //sample noisetex; r stores costheta, g stores sintheta
-                float2 mynoise = tex2D(noiseTexture, IN.texCoord.xy * noiseMultiplier).xy;
-
-                // rotation
-                float2 offsetTransformed = reflect(offset, mynoise);
-
-                // weight with projected coordinate to reach similar kernel size for near and far
-                float2 texcoord = IN.texCoord.xy + offsetTransformed * AREA_SIZE * w;
-
-                float3 sample_position = tex2Dlod(positions, float4(texcoord, 0, 1)).xyz;
-                float3 sample_color = tex2Dlod(colors, float4(texcoord, 0, 1)).xyz;
-
-                float3 vector_to_sample = sample_position - centerPosition.xyz;
-                float length_to_sample = length(vector_to_sample);
-                float3 direction_to_sample = vector_to_sample / length_to_sample;
-
-                // Angle between current normal and direction to sample controls AO intensity.
-                float cos_angle = dot(direction_to_sample, currentNormal);
-                cos_angle = max(cos_angle, 0.0f);
-
-                // distance between current position and sample position controls AO intensity.
-                float distance_intensity = 
-                        (SAMPLE_INTENSITY * DISTANCE_SCALE) / (DISTANCE_SCALE + length_to_sample * length_to_sample);
-
-                // if normal perpenticular to view dir, only half of the samples count
-                float view_correction = 1.0f + VIEW_CORRECTION_SCALE * (1.0f - dot(currentViewDir, currentNormal));
-
-                total_color.w -= cos_angle * distance_intensity * view_correction;
-
-                const float scale_factor = 0.3f;
-                total_color.xyz += cos_angle * distance_intensity * view_correction * sample_color * scale_factor;
-        }
-
-        return saturate(total_color);
 }
 
@@ -220 +142 @@
         const float currentDepth = currentCol.w;
 
-        //float4 new_col = (float4)ssao(IN, positions, noiseTexture, samples, normal, viewDir, noiseMultiplier, centerPosition);
-        float4 new_col = globIllum(IN, colors, positions, noiseTexture, samples, normal, viewDir, noiseMultiplier, centerPosition); 
-        
+        const float ao = ssao(IN, positions, noiseTexture, samples, normal, viewDir, noiseMultiplier, centerPosition);
+                
 
         /////////////////
-        //-- compute temporally smoothed value
+        //-- compute temporally smoothing
 
         float4 realPos = centerPosition * maxDepth;
@@ -240 +161 @@
         const float depthDif = 1.0f - newDepth / oldDepth;
 
+
         if ((tex.x >= 0.0f) && (tex.x < 1.0f) && 
                 (tex.y >= 0.0f) && (tex.y < 1.0f) && 
-                (abs(depthDif)  < 1e-4f))
+                (abs(depthDif)  < 1e-3f))
         {
-                OUT.illum_col = new_col * expFactor + oldCol * float4(1.0f - expFactor);
+                OUT.illum_col.x = ao * expFactor + oldCol.x * (1.0f - expFactor);
         }
         else
         {
-                OUT.illum_col = new_col;
+                OUT.illum_col.x = ao;
         }
 
-        //const float ao = OUT.illum_col.x;
-        const float ao = OUT.illum_col.w;
+        OUT.combined_col = currentCol * OUT.illum_col.x;
+        OUT.illum_col.w = currentDepth;
 
-        //OUT.combined_col = (currentCol + OUT.illum_col) * ao;
-        OUT.combined_col = currentCol * ao;
-
-        OUT.illum_col.w = currentDepth;
+        
 
         return OUT;
 }
-
-/*
-pixel combined(fragment IN, 
-                           uniform sampler2D colors,
-                           uniform sampler2D ssaoTex
-                   )
-{
-        pixel OUT;
-
-        float4 col = tex2D(colors, IN.texCoord.xy);
-        float4 ao = tex2D(ssaoTex, IN.texCoord.xy);
-        //float4 illum = tex2D(ssaoTex, IN.texCoord.xy);
-
-        OUT.illum_col = col * ao;
-
-        return OUT;
-}*/