Do you have an idea, how to make the axis "grid-like"?
Sorry, I'm not really sure what you mean by more "grid-like". PLplot
has a function called plgriddata() that will let you grid irregularly
spaced data for the purposes of plotting it. It is documented and
there are examples of its use in example 21.
With that I mean, that the ticks (main ticks) are elongated,
so that the x- y- and z-axis is translated parallel.
Then it is easier to see the values of the data in 3D-projection.
Something like drawing a 3D-bounding-box cube around the area
that is displayed...
I hope these words are more easy to understand.
I have not found a documented option for that for plbox3(),
where I had awaited it to find.
Something like 3D-ticks / elongated ticks.