Hi,

I have changed wall subtypes before in my layout. e.g. Using Bruce Mutton's

code metapost

def l_wall_unsurveyed (expr P) =
T:=identity;
pickup PenC;
thdraw P dashed evenly scaled (2*optical_zoom);
enddef;
endcode

However, I can't get this working on the default l_wall type. Any changes, including using the same style as in the above l_wall_unsurveyed example get ignored. e.g.

code metapost

def l_wall (expr P) =
T:=identity;
pickup PenC;
thdraw P dashed evenly scaled (2*optical_zoom);
enddef;
endcode

I'm not sure what I'm missing. I'm first trying to prove I can override this, and then working on a wall style with a shadow or external cross-hatching.

Thanks,

Paul