osg::Texture*
GroundCover::createTexture() const
{
    osg::Texture2DArray* tex = new osg::Texture2DArray();

    int arrayIndex = 0;
    float s = -1.0f, t = -1.0f;

    for(int b=0; b<getBiomes().size(); ++b)
    {
        const GroundCoverBiome* biome = getBiomes()[b].get();

        for(int i=0; i<biome->getBillboards().size(); ++i, ++arrayIndex)
        {
            const GroundCoverBillboard& bb = biome->getBillboards()[i];

            osg::ref_ptr<osg::Image> im;

            // make sure the texture array is POT - required now for mipmapping to work
            if ( s < 0 )
            {
                s  = nextPowerOf2(bb._image->s());
                t  = nextPowerOf2(bb._image->t());
                tex->setTextureSize(s, t, getTotalNumBillboards());
            }

            if ( bb._image->s() != s || bb._image->t() != t )
            {
                ImageUtils::resizeImage( bb._image.get(), s, t, im );
            }
            else
            {
                im = bb._image.get();
            }

            tex->setImage( arrayIndex, im.get() );
        }
    }

    tex->setFilter(tex->MIN_FILTER, tex->NEAREST_MIPMAP_LINEAR);
    tex->setFilter(tex->MAG_FILTER, tex->LINEAR);
    tex->setWrap  (tex->WRAP_S, tex->CLAMP_TO_EDGE);
    tex->setWrap  (tex->WRAP_T, tex->CLAMP_TO_EDGE);
    tex->setUnRefImageDataAfterApply( true );
    tex->setMaxAnisotropy( 4.0 );
    //tex->setResizeNonPowerOfTwoHint( false ); // no longer legal for tex2darray!

    return tex;
}