+ vec4 vcolour0 = texture( uTexMain, aUv + vdir*vrand.x );
+ vec4 vcolour1 = texture( uTexMain, aUv + vdir*vrand.y );
+ vec4 vcolour2 = texture( uTexMain, aUv + vdir*vrand1.x );
+ vec4 vcolour3 = texture( uTexMain, aUv + vdir*vrand1.y );
+
+ FragColor = ( vcolour0 + vcolour1 + vcolour2 + vcolour3 ) * 0.25;