scene:add

(scene:add v &rest solids)

Adds solids to the viewer's contents and answers the last one. Every argument is a solid or a LIST of solids, spliced in order, so a constructor that answers three of them -- geom:triad -- is handed over exactly like one that answers one. Anything else is refused here, naming it: a non-solid in the contents would otherwise surface a frame later, from inside the draw callback, as a geom:user-data dispatch failure. Nothing is added until every argument has been checked. A solid's mesh reaches the GPU the first time it is DRAWN, not here, and stays there: the per-frame cost of a solid is one 4x4 matrix and one draw call, never a triangle. 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:add *v* (geom:box 100) (geom:triad :at (geom:vec3 0 0 0)))
#<GEOM:SOLID "z" 73 vertices 73 facets>