%--------------------------
 % @Author: Jingqiao Hu
 % @Date: 2021-02-28 17:01:58
 % @LastEditTime: 2021-03-01 18:10:28
%--------------------------
function F = deform_grad_2scale(sort_h, edofMat, dNh, eleNum_mi, U, regulated_matrix)

    nele_ma = size(edofMat, 1);
    F = cell(8, nele_ma);

    I = eye(3);
    initF = repmat(I(:), 1, eleNum_mi);    

    for ele = 1:nele_ma              
        edof = edofMat(ele, :);
        ue = U(edof); % including macro U and control pnts

        Re = regulated_matrix{ele};
        he = Re * ue;

        % reorder micro-displacement to [24 * eleNum_mi]
        he_reorder = sparse(sort_h(:,1), sort_h(:,2), he(sort_h(:,3)));

        %% 2. compute deform grad   
        for gp = 1:8
            Be = dNh{gp};
            F{gp, ele} = Be * he_reorder + initF; % 9 * eleNum_mi
        end
    end
end