source files: [xc]cmr.[ch]
(SEND <cmr> :FRAME-THINGS [:THINGS <thingList>] [:FRAME-TIGHTLY t])
This message is simply forwarded to the viewing transform.
If :THINGS is not provided, it should be present as a property on either the <cmr> or else the MATRIX44 transform used by the <cmr>.
See the :DRAW command for a description of the <thinglist>.