# Extensible Scene Graph Manager: Import and Export Filters

### Import filters:

In this release, the following input filters are provided (besides the toy example):

Import filter description | import filter class name | include file
VRML V2.0 UTF8 file format | vrml2_utf8::parser | vrml2_utf8/parser.H
PLY file format (requires libply library) | ply::importer | ply/importer.H
.so (shared object) | cso::importer | cso/importer.H

If you'd like to know how you can create your own importers, have a look at how to create a scene graph. There is an example, toy, importer in FILTERS/toy and the example program using this toy importer in PROGS/toy.

### Export filters:

Besides the toy example, this release provides the following export filters:

Export filter description | export filter class name | include file
VRML V2.0 UTF8 file format | vrml2_itf8::exporter | vrml2_utf8/exporter.H
MGF file format | mgf::exporter | mgf/exporter.H
NFF file format | nff::exporter | nff/exporter.H
C++ source code | cso::exporter | cso/exporter.H

If you'd like to learn how to write your own export filters, have a look at the toy example (filter in FILTERS/toy and program using it in PROGS/toy). You will often find it convenient to let your exporter call an appropriate renderer object that does the real job of traversing the scene graph and converting its nodes into the format you'd like (see e.g. FILTERS/nff). Not all exporters need to do so however (e.g. the default vrml2_utf8::exporter doesn't work that way).