HDAO

Posted 2020-09-22 DeanWang

#version 440
#define int2 ivec2

#define int3 ivec3

#define int4 ivec4



#define half float

#define half2 vec2

#define half3 vec3

#define half4 vec4



#define float2 vec2

#define float3 vec3

#define float4 vec4



#define float2x2 mat2

#define float3x3 mat3

#define float3x4 mat3x4

#define float4x4 mat4

#define saturate(value) clamp((value), 0.0f, 1.0f)

#define rsqrt(value) inversesqrt(value)

#define RING_1    (1)
#define RING_2    (2)
#define RING_3    (3)
#define RING_4    (4)
#define NUM_RING_1_GATHERS    2
#define NUM_RING_2_GATHERS    6
#define NUM_RING_3_GATHERS    12
#define NUM_RING_4_GATHERS    20

// Ring sample pattern
const float2 g_f2HDAORingPattern[NUM_RING_4_GATHERS] =
{
    // Ring 1
    { 1, -1 },
    { 0, 1 },

    // Ring 2
    { 0, 3 },
    { 2, 1 },
    { 3, -1 },
    { 1, -3 },

    // Ring 3
    { 1, -5 },
    { 3, -3 },
    { 5, -1 },
    { 4, 1 },
    { 2, 3 },
    { 0, 5 },

    // Ring 4
    { 0, 7 },
    { 2, 5 },
    { 4, 3 },
    { 6, 1 },
    { 7, -1 },
    { 5, -3 },
    { 3, -5 },
    { 1, -7 },
};

// Ring weights
const float4 g_f4HDAORingWeight[NUM_RING_4_GATHERS] =
{
    // Ring 1 (Sum = 5.30864)
    { 1.00000, 0.50000, 0.44721, 0.70711 },
    { 0.50000, 0.44721, 0.70711, 1.00000 },

    // Ring 2 (Sum = 6.08746)
    { 0.30000, 0.29104, 0.37947, 0.40000 },
    { 0.42426, 0.33282, 0.37947, 0.53666 },
    { 0.40000, 0.30000, 0.29104, 0.37947 },
    { 0.53666, 0.42426, 0.33282, 0.37947 },

    // Ring 3 (Sum = 6.53067)
    { 0.31530, 0.29069, 0.24140, 0.25495 },
    { 0.36056, 0.29069, 0.26000, 0.30641 },
    { 0.26000, 0.21667, 0.21372, 0.25495 },
    { 0.29069, 0.24140, 0.25495, 0.31530 },
    { 0.29069, 0.26000, 0.30641, 0.36056 },
    { 0.21667, 0.21372, 0.25495, 0.26000 },

    // Ring 4 (Sum = 7.00962)
    { 0.17500, 0.17365, 0.19799, 0.20000 },
    { 0.22136, 0.20870, 0.24010, 0.25997 },
    { 0.24749, 0.21864, 0.24010, 0.28000 },
    { 0.22136, 0.19230, 0.19799, 0.23016 },
    { 0.20000, 0.17500, 0.17365, 0.19799 },
    { 0.25997, 0.22136, 0.20870, 0.24010 },
    { 0.28000, 0.24749, 0.21864, 0.24010 },
    { 0.23016, 0.22136, 0.19230, 0.19799 },
};

const float g_fRingWeightsTotal[RING_4] =
{
    5.30864,
    11.39610,
    17.92677,
    24.93639,
};

#define NUM_NORMAL_LOADS 4
const int2 g_i2NormalLoadPattern[NUM_NORMAL_LOADS] =
{
    { 1, 8 },
    { 8, -1 },
    { 5, 4 },
    { 4, -4 },
};

//--------------------------------------------------------------------------------------
// Helper function to gather Z values
//--------------------------------------------------------------------------------------
float LinearEyeDepth(float d, float2 zConstants)
{
    float z1 = zConstants.x;
    float z2 = zConstants.y;
    float z = (1.0f / (d * z1 + z2));
    return z;
}

float4 LinearEyeDepth(float4 d, float2 zConstants)
{
    float4 z1 = zConstants.xxxx;
    float4 z2 = zConstants.yyyy;
    float4 z = (1.0f / (d * z1 + z2));
    return z;
}

float4 GatherZSamples(sampler2D depthTex, float2 f2TexCoord, float2 zConstants)
{
    float4 f4Gather;
    f4Gather.x = textureLodOffset(depthTex,f2TexCoord, 0, int2(0, 1)).x;   
    f4Gather.y = textureLodOffset(depthTex,f2TexCoord, 0, int2(1, 1)).x;   
    f4Gather.z = textureLodOffset(depthTex,f2TexCoord, 0, int2(1, 0)).x;   
    f4Gather.w = textureLodOffset(depthTex,f2TexCoord, 0, int2(0, 0)).x;   

    float4 f4Ret = LinearEyeDepth(f4Gather, zConstants);
    return f4Ret;
}

float3 ReconstructCSPosition(float2 posInNDC, float projZ, float4x4 mInvProj)
{
    float4 pos = float4(posInNDC, projZ * 2 - 1, 1);

    //float4 posInCS = mul(pos, mInvProj);
    float4 posInCS = mInvProj * pos;
    return posInCS.xyz / posInCS.w;
}

float3 GetPosition(sampler2D depthTex,float2 uv, float4x4 mInvProj)
{
    float3 P;
    P.z = textureLod(depthTex, uv, 0).x;
    // assume DirectX style UV,
    // remap x: [0,1]->[-1,1]    y:[0,1]->[1,-1]
    float2 ndcPos = (uv - 0.5f) * float2(2, -2);
    P = ReconstructCSPosition(ndcPos, P.z, mInvProj);
    return P;
}

float3 GetCameraXYZFromDepth(float depth, float2 UV, float4x4 invProj)
{
    float4 ndcPos = float4(UV.x * 2.0f - 1.0f, (1.0f - UV.y) * 2.0f - 1.0f, depth, 1);
    return ReconstructCSPosition(ndcPos.xy, ndcPos.z, invProj);
}

float GeometryRejectionTest( int2 i2ScreenCoord, float2 rtSize, float4x4 invProj, sampler2D a_depthTex)
{
    float3 f3N[3];
    float3 f3Pos[3];
    float3 f3Dir[2];
    float fDot;
    float fSummedDot = 0.0f;
    int2 i2MirrorPattern;
    int2 i2OffsetScreenCoord;
    int2 i2MirrorOffsetScreenCoord;
    float fDepth;
    
    fDepth = texelFetch(a_depthTex,i2ScreenCoord, 0 ).x;
    
    f3Pos[0] = GetCameraXYZFromDepth( fDepth, i2ScreenCoord / rtSize.xy, invProj);

    for( int iNormal=0; iNormal<NUM_NORMAL_LOADS; iNormal++ )
    {
        i2MirrorPattern = ( g_i2NormalLoadPattern[iNormal] + int2( 1, 1 ) ) * int2( -1, -1 );
        i2OffsetScreenCoord = i2ScreenCoord + g_i2NormalLoadPattern[iNormal];
        i2MirrorOffsetScreenCoord = i2ScreenCoord + i2MirrorPattern;

        // Clamp our test to screen coordinates
        //i2OffsetScreenCoord = ( i2OffsetScreenCoord > (rtSize.xy - float2( 1.0f, 1.0f ) ) ) ? (rtSize.xy - float2( 1.0f, 1.0f ) ) : ( i2OffsetScreenCoord );
        int2 rtSizeMinusOne = ivec2(rtSize.xy - float2( 1.0f, 1.0f ));
        i2OffsetScreenCoord.x = i2OffsetScreenCoord.x > rtSizeMinusOne.x?rtSizeMinusOne.x:i2OffsetScreenCoord.x;
        i2OffsetScreenCoord.y = i2OffsetScreenCoord.y > rtSizeMinusOne.y?rtSizeMinusOne.y:i2OffsetScreenCoord.y;

        //i2MirrorOffsetScreenCoord = ( i2MirrorOffsetScreenCoord > (rtSize.xy - float2( 1.0f, 1.0f ) ) ) ? (rtSize.xy - float2( 1.0f, 1.0f ) ) : ( i2MirrorOffsetScreenCoord );
        i2MirrorOffsetScreenCoord.x = i2MirrorOffsetScreenCoord.x > rtSizeMinusOne.x?rtSizeMinusOne.x:i2MirrorOffsetScreenCoord.x;
        i2MirrorOffsetScreenCoord.y = i2MirrorOffsetScreenCoord.y > rtSizeMinusOne.y?rtSizeMinusOne.y:i2MirrorOffsetScreenCoord.y;

        //i2OffsetScreenCoord = ( i2OffsetScreenCoord < 0 ) ? ( 0 ) : ( i2OffsetScreenCoord );
        //i2MirrorOffsetScreenCoord = ( i2MirrorOffsetScreenCoord < 0 ) ? ( 0 ) : ( i2MirrorOffsetScreenCoord );
        if(i2OffsetScreenCoord.x<0) {i2OffsetScreenCoord.x = 0;}
        if(i2OffsetScreenCoord.y<0) {i2OffsetScreenCoord.y = 0;}
        if(i2MirrorOffsetScreenCoord.x<0) {i2MirrorOffsetScreenCoord.x = 0;}
        if(i2MirrorOffsetScreenCoord.y<0) {i2MirrorOffsetScreenCoord.y = 0;}

        fDepth = texelFetch(a_depthTex,i2OffsetScreenCoord,0).x;
        f3Pos[1] = GetCameraXYZFromDepth( fDepth, i2OffsetScreenCoord / rtSize.xy, invProj );
        fDepth = texelFetch(a_depthTex,i2MirrorOffsetScreenCoord,0).x;
        f3Pos[2] = GetCameraXYZFromDepth( fDepth, i2MirrorOffsetScreenCoord / rtSize.xy, invProj);
        
        f3Dir[0] = f3Pos[1] - f3Pos[0];
        f3Dir[1] = f3Pos[2] - f3Pos[0];
        
        f3Dir[0] = normalize( f3Dir[0] );
        f3Dir[1] = normalize( f3Dir[1] );
        
        fDot = dot( f3Dir[0], f3Dir[1] );
        
        fSummedDot += ( fDot + 2.0f );
    }
        
    return ( fSummedDot * 0.125f );
}

////////////////////////////these functions are used for generating ao.gb for ssaoblur/////////////////////////////
/** Used for packing Z into the GB channels */
float CSZToKey(float z, float a_fZFar)
{
    return saturate(z * (1.0 / a_fZFar));
}

/** Used for packing Z into the GB channels */
float2 packKey(float key)
{
    float2 outp;
    // Round to the nearest 1/256.0
    float temp = floor(key * 256.0);

    // Integer part
    outp.x = temp * (1.0 / 256.0);

    // Fractional part
    outp.y = key * 256.0 - temp;
    return outp;
}

float UnpackKey(float2 fDepthGb)
{
    return fDepthGb.x * (256.0 / 257.0) + fDepthGb.y * (1.0 / 257.0);
}

layout(binding = 12 ) uniform HardcodeConstantBuffer
{
    vec4 dummy0;
    vec4 dummy1;
    vec4 dummy2;
    vec4 dummy3;
    vec4 dummy4;
    vec4 dummy5;
    vec4 dummy6;
    vec4 dummy7;
    vec4 dummy8;
    vec4 dummy9;
    vec4 dummy10;
    vec4 dummy11;
    vec4 dummy12;
    vec4 dummy13;
    vec4 dummy14;
    vec4 dummy15;
    vec4 dummy16;
    float4x4 g_mInvProj;
    float4x4 g_mInvTransposeWorldToCamera;
    vec4 g_RTSize;
    vec4 g_HDAO_ZConstants;
    vec4 g_Falloff;
    vec4 g_MiscParam0;
    vec4 g_MiscParam1;
};

#define g_FadeoutScale  g_MiscParam0.x // Param : FadeoutScale
#define g_RejectRadius  g_MiscParam0.y // Param : RejectRadius
#define g_AcceptRadius  g_MiscParam0.z // Param : AcceptRadius
#define g_AcceptAngle   g_MiscParam0.w // Param : AcceptAngle

#define g_HDAOIntensity g_MiscParam1.x // Param : Intensity
#define g_KernelScale   g_MiscParam1.y // Param : KernelScale
#define g_CameraFar     g_MiscParam1.z // Param : CameraFar
#define g_UseNormal     false
#define g_HDAO_NormalScale 1.0f

layout(binding = 0) uniform sampler2D g_depthTex;
//layout(binding = 1) uniform sampler2D g_normalTex;

struct PS_Input
{
    float4 Position;
    float2 uv;
};

in PS_Input IN;
out vec4 myOut;
void main()
{
    float2 rYuv = float2(IN.uv.x, 1 - IN.uv.y);

    // Compute integer screen coord, and store off the inverse of the RT Size
    float2 f2InvRTSize = 1.0f / g_RTSize.xy;
    float2 f2ScreenCoord = rYuv * g_RTSize.xy;
    int2 i2ScreenCoord = int2(f2ScreenCoord);

    // View space point being shaded
    float3 f3CameraPos = GetPosition(g_depthTex, rYuv.xy, g_mInvProj);
    // generate .gb for ssaoblur
    float2 f2Ogb = packKey(CSZToKey(f3CameraPos.z, g_CameraFar));

    float fDot = GeometryRejectionTest(i2ScreenCoord, g_RTSize.xy, g_mInvProj, g_depthTex);

    if (fDot > 0.5f)
    {
        // Sample the center pixel for camera Z
        float2 f2TexCoord = float2(f2ScreenCoord * f2InvRTSize);

        float fDepth = textureLod(g_depthTex, f2TexCoord,0).x;

        float fCenterZ = LinearEyeDepth(fDepth, g_HDAO_ZConstants.xy);

        float fOffsetCenterZ = fCenterZ;

        float2 f2KernelScale = float2(g_KernelScale, g_KernelScale);

        float4 f4Occlusion = float4(0.0f);

        // Loop through each gather location, and compare with its mirrored location
        for (int iGather = 0; iGather < NUM_RING_4_GATHERS; iGather++)
        {
            float4 f4Diff = float4(0.0f);
            float4 f4SampledZ[2];
            float4 f4Compare[2];

            float2 f2MirrorScreenCoord = ((f2KernelScale * g_f2HDAORingPattern[iGather]) + float2(1.0f, 1.0f)) * float2(-1.0f, -1.0f);

            f2TexCoord = float2((f2ScreenCoord + (f2KernelScale * g_f2HDAORingPattern[iGather])) * f2InvRTSize);
            float2 f2MirrorTexCoord = float2((f2ScreenCoord + (f2MirrorScreenCoord)) * f2InvRTSize);

            // Sample
            f4SampledZ[0] = GatherZSamples(g_depthTex, f2TexCoord, g_HDAO_ZConstants.xy);
            f4SampledZ[1] = GatherZSamples(g_depthTex, f2MirrorTexCoord, g_HDAO_ZConstants.xy);

            // Detect valleys
            f4Diff = fCenterZ.xxxx - f4SampledZ[0];

            //f4Compare[0] = (f4Diff < g_RejectRadius.xxxx) ? (1.0f) : (0.0f);
            f4Compare[0] = vec4(lessThan(f4Diff, g_RejectRadius.xxxx));
            //f4Compare[0] *= (f4Diff > g_AcceptRadius.xxxx) ? (1.0f) : (0.0f);
            f4Compare[0] *= vec4(greaterThan(f4Diff,  g_AcceptRadius.xxxx));

            f4Diff = fCenterZ.xxxx - f4SampledZ[1];

            //f4Compare[1] = (f4Diff < g_RejectRadius.xxxx) ? (1.0f) : (0.0f);
            f4Compare[1] = vec4(lessThan(f4Diff, g_RejectRadius.xxxx));
            //f4Compare[1] *= (f4Diff > g_AcceptRadius.xxxx) ? (1.0f) : (0.0f);
             f4Compare[1] *= vec4(greaterThan(f4Diff,  g_AcceptRadius.xxxx));

            f4Occlusion.xyzw += (g_f4HDAORingWeight[iGather].xyzw * (f4Compare[0].xyzw * f4Compare[1].zwxy) * fDot);
        }

        // Finally calculate the HDAO occlusion value
        float fOcclusion = 0;
        fOcclusion = ((f4Occlusion.x + f4Occlusion.y + f4Occlusion.z + f4Occlusion.w) / (2.0f * g_fRingWeightsTotal[RING_4 - 1]));

        float falloff = 1 - saturate((fCenterZ - g_Falloff.x) / (g_Falloff.y));

        fOcclusion *= g_HDAOIntensity * falloff;

        fOcclusion = 1.0f - saturate(fOcclusion);

        myOut = float4(fOcclusion, f2Ogb, 1.0f);
    }
    else
    {
        myOut = float4(1.0f, f2Ogb, 1.0f);
    }
}

#version 440
#define int2 ivec2

#define int3 ivec3

#define int4 ivec4



#define half float

#define half2 vec2

#define half3 vec3

#define half4 vec4



#define float2 vec2

#define float3 vec3

#define float4 vec4



#define float2x2 mat2

#define float3x3 mat3

#define float3x4 mat3x4

#define float4x4 mat4


#define saturate(value) clamp((value), 0.0f, 1.0f)

#define rsqrt(value) inversesqrt(value)


float UnpackKey(float2 fDepthGb)
{
    return fDepthGb.x * (256.0 / 257.0) + fDepthGb.y * (1.0 / 257.0);
}

layout(binding = 12 ) uniform HardcodeConstantBuffer
{
    vec4 dummy0;
    vec4 dummy1;
    vec4 dummy2;
    vec4 dummy3;
    vec4 dummy4;
    vec4 dummy5;
    vec4 dummy6;
    vec4 dummy7;
    vec4 dummy8;
    vec4 dummy9;
    vec4 dummy10;
    vec4 dummy11;
    vec4 dummy12;
    vec4 dummy13;
    vec4 dummy14;
    vec4 dummy15;
    vec4 dummy16;
    vec4 v4_g_ssao_BlurFilterDistance;
    vec4 v4_g_mainTex_TexelSize;
    vec4 v4_g_BlurAxis;
    vec4 v4_g_EdgeSharpness;
};

#define g_ssao_BlurFilterDistance v4_g_ssao_BlurFilterDistance.x
#define g_mainTex_TexelSize v4_g_mainTex_TexelSize.xy
#define g_BlurAxis v4_g_BlurAxis.xy
#define g_EdgeSharpness v4_g_EdgeSharpness.x

struct PS_Input
{
    float4 Position;
    float2 uv ;
};

//--------------------------------------------------------------------------------------
// After pack z value in aoTex.gb(integer and fraction)  unpack it  to add together and in (0,1)
//--------------------------------------------------------------------------------------
const float gaussian[5] = { 0.153170, 0.144893, 0.122649, 0.092902, 0.062970 };  // stddev = 2.0

layout(binding = 0) uniform sampler2D g_mainTex;
//--------------------------------------------------------------------------------------
// Blur SSAO ways
//--------------------------------------------------------------------------------------
in PS_Input IN;
out vec4 myOut;
void main()
{
    float4 fragment = float4(1, 1, 1, 1);
//reverse y axis
    //float2 ssC = IN.uv.xy;
    float2 rYuv = float2(IN.uv.x, 1 - IN.uv.y);
    float2 ssC = rYuv.xy;
    float4 temp = textureLod(g_mainTex,rYuv, 0);

    float2 passthrough2 = temp.gb;
    float key = UnpackKey(passthrough2);

    float sum = temp.r;

    // Base weight for depth falloff. Increase this for more blurriness, decrease it for better edge discrimination

    float BASE = gaussian[0] * 0.5; // ole: i decreased
    float totalWeight = BASE;
    sum *= totalWeight;


    // We already handled the zero case above.  This loop should be unrolled and the branch discarded
    {
        temp = textureLod(g_mainTex, ssC + g_BlurAxis * g_mainTex_TexelSize.xy * (-4.0f * g_ssao_BlurFilterDistance), 0);
        float tapKey = UnpackKey(temp.gb);
        float value = temp.r;

        // spatial domain: offset gaussian tap
        float weight = 0.3 + gaussian[4];

        // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
        // these two keys is depth value which we stored in AoTex generate in .gb
        weight *= max(0.0, 1.0 - (2000.0 * g_EdgeSharpness) * abs(tapKey - key));
        sum += value * weight;
        totalWeight += weight;
    }
    {
        temp = textureLod(g_mainTex, ssC + g_BlurAxis * g_mainTex_TexelSize.xy * (-3.0f * g_ssao_BlurFilterDistance), 0);

        float tapKey = UnpackKey(temp.gb);
        float value = temp.r;

        // spatial domain: offset gaussian tap
        float weight = 0.3 + gaussian[3];

        // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
        // these two keys is depth value which we stored in AoTex generate in .gb
        weight *= max(0.0, 1.0 - (2000.0 * g_EdgeSharpness) * abs(tapKey - key));
        sum += value * weight;
        totalWeight += weight;
    }
    {
        temp = textureLod(g_mainTex, ssC + g_BlurAxis * g_mainTex_TexelSize.xy * (-2.0f * g_ssao_BlurFilterDistance), 0);
        float tapKey = UnpackKey(temp.gb);
        float value = temp.r;

        // spatial domain: offset gaussian tap
        float weight = 0.3 + gaussian[2];

        // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
        // these two keys is depth value which we stored in AoTex generate in .gb
        weight *= max(0.0, 1.0 - (2000.0 * g_EdgeSharpness) * abs(tapKey - key));
        sum += value * weight;
        totalWeight += weight;
    }
    {
        temp = textureLod(g_mainTex,ssC + g_BlurAxis * g_mainTex_TexelSize.xy * (-1.0f * g_ssao_BlurFilterDistance), 0);
        float tapKey = UnpackKey(temp.gb);
        float value = temp.r;

        // spatial domain: offset gaussian tap
        float weight = 0.3 + gaussian[1];

        // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
        // these two keys is depth value which we stored in AoTex generate in .gb
        weight *= max(0.0, 1.0 - (2000.0 * g_EdgeSharpness) * abs(tapKey - key));
        sum += value * weight;
        totalWeight += weight;
    }
    {
        temp = textureLod(g_mainTex,ssC + g_BlurAxis * g_mainTex_TexelSize.xy * (1.0f * g_ssao_BlurFilterDistance), 0);

        float tapKey = UnpackKey(temp.gb);
        float value = temp.r;

        // spatial domain: offset gaussian tap
        float weight = 0.3 + gaussian[1];

        // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
        //these two keys is depth value which we stored in AoTex generate in .gb
        weight *= max(0.0, 1.0 - (2000.0 * g_EdgeSharpness) * abs(tapKey - key));
        sum += value * weight;
        totalWeight += weight;
    }
    {
        temp = textureLod(g_mainTex,ssC + g_BlurAxis * g_mainTex_TexelSize.xy * (2.0f * g_ssao_BlurFilterDistance),0);
        float tapKey = UnpackKey(temp.gb);
        float value = temp.r;

        // spatial domain: offset gaussian tap
        float weight = 0.3 + gaussian[2];

        // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
        // these two keys is depth value which we stored in AoTex generate in .gb
        weight *= max(0.0, 1.0 - (2000.0 * g_EdgeSharpness) * abs(tapKey - key));
        sum += value * weight;
        totalWeight += weight;
    }
    {
        temp = textureLod(g_mainTex,ssC + g_BlurAxis * g_mainTex_TexelSize.xy * (3.0f * g_ssao_BlurFilterDistance),0);
        float tapKey = UnpackKey(temp.gb);
        float value = temp.r;

        // spatial domain: offset gaussian tap
        float weight = 0.3 + gaussian[3];

        // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
        // these two keys is depth value which we stored in AoTex generate in .gb
        weight *= max(0.0, 1.0 - (2000.0 * g_EdgeSharpness) * abs(tapKey - key));
        sum += value * weight;
        totalWeight += weight;
    }
    {
        temp = textureLod(g_mainTex,ssC + g_BlurAxis * g_mainTex_TexelSize.xy * (4.0f * g_ssao_BlurFilterDistance), 0);
        float tapKey = UnpackKey(temp.gb);
        float value = temp.r;

        // spatial domain: offset gaussian tap
        float weight = 0.3 + gaussian[4];

        // range domain (the "bilateral" weight). As depth difference increases, decrease weight.
        //these two keys is depth value which we stored in AoTex generate in .gb
        weight *= max(0.0, 1.0 - (2000.0 * g_EdgeSharpness) * abs(tapKey - key));
        sum += value * weight;
        totalWeight += weight;
    }

    const float epsilon = 0.0001;

    fragment = vec4(sum / (totalWeight + epsilon));

    fragment.gb = passthrough2;

    myOut = fragment;
}