Dunno about lightwave, but with Maya you get a few options.
the first is the obj file format (documented on www.wotsit.org)) which is an ascii ile that supports polygonal models only. The maya Ascii files use 10 mel commands to reconstruct the scene,
the file format docs are in the Maya docs here:
generally this isn’t a nice file format cos it uses a lot of scripting stuff, and you still have to know the Maya node types and all arguments for them. For example if you export a polycube, it won’t give you any vertex positions, it’ll give you the creation node that was used to make the cube and the arguments used to create it. If you then delete all history on the cube, it will then give you the actual geometry data.
The maya binary file is very similar, but refers to nodes using a 32bit ID value. Bear in mind that it will also hold things like camera’s, and user options, ui settings etc. You can reverse engineer the format but it takes a LONG time, and there is no documentation provided by Alias.
The only other format is the rtg file, but I’d avaoid it like the plague because it’s very limited and doesn’t actually do what it claims.
The best option is to write our own file translator in the devkit, the best place to start is to look at the objExport source code provided in the devkit :
related mel option script that define the ui options :
the other useful exmaple for getting data (if you want to add skinning to the format quite easily) is the skin Weight export :
hope thats of some help.