Description

Use the property/value pair 'light',V in the argument list of surfl or trisurfl to define the direction of light.

The 3-Vector V=[x,y,z] or the 2-vector V=[az,el] give the normalized coordinates of the light source at infinity.

Examples

deff('z=f(x,y)','z=x.^2-y.^2');    
surfl(-1:0.1:1,-1:0.1:1,f,'shading','interp','light',[0 0 1]);

Authors