From WarzoneWiki

3ds2pie can be used to convert Autodesk 3DS files (which are quite well supported in the industry) to PIE, the model format used internally by Warzone 2100

Status

There exists a pre-alpha Window's release at http://svn.gna.org/svn/warzone/trunk/tools/conversion_tools/3ds2pie.c

Compiling

Debian GNU/Linux

You need to have the following packages installed:

• libqt4-dev (maybe an earlier version of libqt would work),
• lib3ds-dev
• build-essential

After that, as an unprivledged user, run the follwing in 3ds2pie source directory:

qmake
make

In that directory, you now should have a binary named 3ds2pie_gui