Plot a plane through 3 points

plotPlane.m

% (c) Jakob Nikolas Kather 2015
% contact: http://www.kather.me

% this function plots a plane through the points x,y,z in a 3D plot

function normal = plotPlane(x,y,z)

    % plot triangle through x y z, optional
    % fill3([x(1),y(1),z(1)],[x(2),y(2),z(2)],[x(3),y(3),z(3)],'b') 

    % calculate normal vector
    normal = cross((x-z),(y-z)) / norm(cross((x-z),(y-z)));
    D = dot(normal,z);

    % plot normal vector at origin
    midP=zeros(1,3);
    plot3([midP(1),midP(1)+normal(1)],[midP(2),midP(2)+normal(2)], ...
        [midP(3),midP(3)+normal(3)],'-','LineWidth',3,'Color',[0,0,0]);
    
    % plot surface in random color
    lo = 0; hi = 1; grid = 10;
    [X,Y] = meshgrid(linspace(lo,hi,grid), linspace(lo,hi,grid));
    Z=(normal(1).*X + normal(2).*Y - D)./normal(3).*(-1);
    C=rand().*ones(size(Z));
    surf(X,Y,Z,C)
    alpha(0.5)

end