scene:grid

(scene:grid v &key extent spacing)

Rebuilds the ground grid: lines every spacing out to extent in both directions on z = 0, in one GPU buffer drawn with one call. A viewer starts with :extent 600 :spacing 50; :extent nil drops the grid altogether, the way (scene:axes v nil) drops the triads. Part of the scene package, a 3-D viewer for geom solids written in rontolisp over metal and appkit and loaded on first use: macOS (java -jar, the rontolisp binary, or a compiled .class / .jar; never a .wasm), with a display. See the solid modeling guide.

CL-USER> (scene:grid *v* :extent 1200 :spacing 100)
NIL