The stereo command sets the current stereo mode. Stereo mode is a convenient way to "see" 3D with two images from slightly different angles.
There are corresponding stereo and stereo_mode settings which are controlled by the stereo command, so you don't need to set them directly.
stereo [ toggle ]
The toggle argument is one of: on, swap, off, quadbuffer, crosseye, walleye, geowall, sidebyside, byrow, bycolumn, checkerboard, custom, anaglyph, dynamic or clonedynamic.
fetch 1ESR, async=0 as cartoon set cartoon_smooth_loops spectrum bg white stereo crosseye