     level1 = level1 > 5.0 ? 5.0 : level1;
 
 #if defined( DISABLE_CUBE_UV_MIPMAP_INTERPOLATION )
+    // round to nearest mipmap if we are not interpolating.
     level0 += min( floor( s + 0.5 ), 5.0 );
 #endif
 

    vec2 uv_21 = getCubeUV(reflectedDirection, r2, level1, textureSize);
    vec4 color21 = envMapTexelToLinear(texture2D(envMap, uv_21));

    vec4 c2 = mix(color11 , color21,  t);
    result = mix(result , c2,  s);

#endif
/*
    vec4 c1 = mix(color10 , color11,  s);
    vec4 c2 = mix(color20 , color21,  s);
    vec4 c3 = mix(c1 , c2,  t);*/

    return vec4( result.rgb, 1.0);
}

#endif

    vec2 uv_20 = getCubeUV(reflectedDirection, r2, level0, textureSize);
    vec4 color20 = envMapTexelToLinear(texture2D(envMap, uv_20));

    vec4 result = mix(color10, color20, t);

#if ! defined( DISABLE_CUBE_UV_MIPMAP_INTERPOLATION )

