[mr.DIMAS]

Сделал сасао. Лепил по статье Борескова. Взял предпоследний шейдер и перевел на HLSL.

     texture depthTexture;

  sampler depthSampler : register(s0) = sampler_state
  {
     texture = <depthTexture>;
  };

  texture rotateTexture;

  sampler rotateSampler : register(s1) = sampler_state
  {
     texture = <rotateTexture>;
  };

  float4x4 invViewProj;

  float screenWidth;
  float screenHeight;

  float rotateMapWidth;
  float rotateMapHeight;

  float radius;
  float distScale;
  float bias;

  float4 main( float2 texCoord : TEXCOORD0 ) : COLOR0 
  {

     float4    rndTable[8];

     rndTable[0] = float4 ( -0.5, -0.5, -0.5, 0.0 );
     rndTable[1] = float4 (  0.5, -0.5, -0.5, 0.0 );
     rndTable[2] = float4 ( -0.5,  0.5, -0.5, 0.0 );
     rndTable[3] = float4 (  0.5,  0.5, -0.5, 0.0 );
     rndTable[4] = float4 ( -0.5, -0.5,  0.5, 0.0 );
     rndTable[5] = float4 (  0.5, -0.5,  0.5, 0.0 );
     rndTable[6] = float4 ( -0.5,  0.5,  0.5, 0.0 );
     rndTable[7] = float4 (  0.5,  0.5,  0.5, 0.0 );

     float depth = tex2D( depthSampler, texCoord ).r;

     float4 screenPosition;
     screenPosition.x =    texCoord.x * 2.0f - 1.0f ;
     screenPosition.y = -( texCoord.y * 2.0f - 1.0f);
     screenPosition.z = depth;
     screenPosition.w = 1.0f;

     float4 position = mul( screenPosition, invViewProj );
     position /= position.w;   

     float2 rotateMapCoord = float2( texCoord.x * screenWidth / rotateMapWidth, texCoord.y * screenHeight / rotateMapHeight );
     float3 plane = tex2D( rotateSampler, rotateMapCoord ).xyz;

     float attenuation = 0.0;

     for( int i = 0; i < 8; i++ )
     {
       float3 sample = reflect( rndTable[ i ].xyz, plane );

       float2 zSampleTexCoord = texCoord + ( radius * sample.xy ) / position.z;
       float    zSample = tex2D( depthSampler, zSampleTexCoord ).r;

       screenPosition.x =    zSampleTexCoord.x * 2.0f - 1.0f ;
       screenPosition.y = -( zSampleTexCoord.y * 2.0f - 1.0f);
       screenPosition.z = zSample;
       screenPosition.w = 1.0f;

       float4 iPosition = mul( screenPosition, invViewProj );
       iPosition /= iPosition.w; 

       float    dist = max ( iPosition.z - position.z, 0.0 ) / distScale;    
       float    occl = 15 * max ( dist * (2.0 - dist), 0.0 );

       attenuation += 1.0 / ( 1.0 + occl*occl );
     }

     attenuation = clamp ( attenuation / 8.0 + bias, 0.0, 1.0 );

     return float4( attenuation, attenuation, attenuation, 1.0f );
  };

Было несколько непонятных магических чисел, но порыскав по сурсам я понял что откуда идет.

Но результат как-то не очень ( картинка в аттаче результат AO ).

Киньте шейдер AO, который можно перевести ( или уже на HLSL ) без плясок с бубном.