copyblur.glsl

#include "Uniforms.glsl"
#include "Samplers.glsl"
#include "Transform.glsl"
#include "ScreenPos.glsl"

varying vec2 vScreenPos;
uniform float cBlurness;

void VS()
{
    mat4 modelMatrix = iModelMatrix;
    vec3 worldPos = GetWorldPos(modelMatrix);
    gl_Position = GetClipPos(worldPos);
    vScreenPos = GetScreenPosPreDiv(gl_Position);
}

void PS()
{
    vec4 viewport = texture2D(sDiffMap, vScreenPos);
    vec4 prevFrame = texture2D(sSpecMap, vScreenPos);
    vec4 Col = viewport*(1.-cBlurness) + prevFrame * cBlurness;
    gl_FragColor = Col;
}

copyblur.xml

<renderpath>
    <rendertarget name="copyframe"  sizedivisor="1 1" tag="Blur" format="rgba"/>
    <command type="quad" tag="Blur" vs="copyblur" ps="copyblur">
        <texture unit="diffuse" name="viewport" />
        <texture unit="specular" name="copyframe" />
        <output index="0" name="viewport" />
        <output index="1" name="copyframe" />
        <parameter name="Blurness" value="0.7" />
    </command>
</renderpath>