Draw a line over dgrid3d and pm3d

Question

I am trying to draw a straight line through one set of points, on top of a 3D grid generated with pm3d and dgrid3d:

setpm3d
set dgrid3d 30,30,2
splot 'map.dat' with lines, 'path.dat' with lines lt -1

The 3d grid is applied to both data sets, I only want it to apply to the first. I've been messing with this for a while and don't seem to be getting anywhere.

Answer 1

Unfortunately, there is no option nodgrid3d (like there is nosurface) to turn off the gridding for individual plot parts. I think you must first plot the gridded data to a temporary file and plot this instead:

set dgrid3d 30,30,3
set table 'map.grid'
splot 'map.dat' w l
unset table

unset dgrid3d
set pm3d
splot 'map.grid' w l, 'path.dat' w l lt -1