%--------------------------
 % @Author: Jingqiao Hu
 % @Date: 2022-05-11 11:01:29
 % @LastEditTime: 2022-05-12 10:27:23
%--------------------------
function recover_def_mmc_surf(ref_nodes, def_nodes, MMCs, optDesign)
    
    microx = 20;

    for ele = 1 : size(ref_nodes, 1)
        
        ref = ref_nodes{ele};
        def = def_nodes{ele};

        [regular_ref, regular_phi] = regular_ref_nodes(ref, MMCs, microx);
        cx = reshape(regular_ref(:,1), microx, microx, microx);
        cy = reshape(regular_ref(:,2), microx, microx, microx);
        cz = reshape(regular_ref(:,3), microx, microx, microx);
        regular_phi = reshape(regular_phi, microx, microx, microx);
        [faces, verts] = isosurface(cx,cy,cz,regular_phi,0);

        % interpolation for the deformed shape
        Fx = scatteredInterpolant(ref(:,1),ref(:,2),ref(:,3),def(:,1),'natural');
        Fy = scatteredInterpolant(ref(:,1),ref(:,2),ref(:,3),def(:,2),'natural');
        Fz = scatteredInterpolant(ref(:,1),ref(:,2),ref(:,3),def(:,3),'natural');

        vqx = Fx(verts); 
        vqy = Fy(verts);
        vqz = Fz(verts);
        stlwrite(['data/stl/',optDesign,'/output1-',num2str(ele),'.stl'], faces, [vqx,vqy,vqz]);
        
        [faces, verts] = isocaps(cx,cy,cz,regular_phi,0);
        vqx = Fx(verts);
        vqy = Fy(verts);
        vqz = Fz(verts);
        stlwrite(['data/stl/',optDesign,'/output2-',num2str(ele),'.stl'], faces, [vqx,vqy,vqz]);
    end
    
end

function [regular_ref, regular_phi] = regular_ref_nodes(ref, MMCs, microx)
    minx = min(ref(:,1)); maxx = max(ref(:,1));
    miny = min(ref(:,2)); maxy = max(ref(:,2));
    minz = min(ref(:,3)); maxz = max(ref(:,3));

    [gx,gy,gz] = meshgrid(linspace(minx, maxx, microx), linspace(miny, maxy, microx), linspace(minz, maxz, microx));
    regular_ref = [gx(:), gy(:), gz(:)];    

    regular_phi = repmat(-1e5, size(regular_ref,1), 1);

    for i = 1 : size(MMCs, 1)
        t  = MMCs(i, 1);
        sp = MMCs(i, 2:4);
        ep = MMCs(i, 5:7);

        phi0 = signed_distance(regular_ref, sp, ep, t);
        regular_phi = max(phi0, regular_phi);
    end
end