function [] = cut_mesh(A,B,C,D)
[V,F] = off("ch_tree.off");

[row,col] = size(V);
[fRow,fCol] = size(F);

under = [];
up = [];

idxUnder = 1;
idxUp = 1;

for i=1:row
    func = A*V(row,1)+B*V(row,2)+C*V(row,3)+D;
    if func<0
        under(idxUnder) = i;
        idxUnder= idxUnder+1;
    end

    if func>0
        up(idxUp) = i;
        idxUp = idxUp + 1;
    end
end


[a,underSize] = size(under);
[b,up] = size(up);

fUnder = [];

for i=1:fRow
    F(fRow,2)==under(j) = 0
    for j=1:under
       if F(fRow,1)==under(j) ||  F(fRow,2)==under(j) ||  F(fRow,3)==under(j)
            isInV = isInV +1 ;
       end
    end

    if isInV ==3
        funder =
    end
end

display(F)

end