Creates a function node, which reads an Alias Wavefront OBJ (Version 3.0) file and creates a scene graph node for it.
l is the parameter list of the function. It must contain a single string, the file name.
When the function is executed (this happens for example when the function node is validated the first time after parsing an input file, or when there are changes in its parameter list at run time) the result node is created (or updated) and connected to the function node as its second node, so that the result can be accessed via the node selection operator [..] (or equivalently [2, ..]).
l is a typeless node, which must be connected to a single string.
The following variations of this keyword exist (some of them define the same internal structures, and are only defined to allow consistent naming conventions):