MATLAB: Three variables (two independent) 3D plotting

Question

I want to plot B, L, and R mutually at the same time (using both 'for' loop).

clear all
clc
R=[];
for B=-20:20;
    M=1;
    X=M+B;l
    T=[];
    for L=-10:10;
        N=2;
        Y=N+X;
        r=B+Y+L^2;
        T=[T r];
    end
    R=[R T];
end
        

Answer 1

M=1;
N=2;
flg=true;
for B=-20:20;
    X=M+B;l
    T=[];
    for L=-10:10;
        Y=N+X;
        r=B+Y+L^2;
        scatter3(B,L,r,'*')
        if flg, flg=~flg; hold on, end
    end
end

results in

More efficient would be and left as "exercise for student" is to vectorize and use meshgrid or internal array expansion.