[UPDATE] Sims 2 GMDC Import/Export for Blender 2.79

This add-on will not work with any Blender version more recent than 2.79b and there are no plans of upgrading it to 2.8x in the foreseeable future.

Over the past few weeks I've been working on a fully featured GMDC Importer Exporter for Blender 2.79, It has now reached the point where it has reached a stable point from a user perspective.
This means that it should be fully functional and no major changes should be happening, though if you find something broken feel free to tell me in the comments.



Supported
- Objects (Including Shadow Meshes)
- Rigs
- Sim Meshes
- Bounding Meshes (Static and Animated)
- Morphs
- Changing vertex order (Adding/Removing vertices)

Limitations
- Face meshes are not supported
- Only one UV layer is supported

Installation
In Blender go to "File > User Preferences > Install Add-on from File"
Navigate to and select the add-on zip you've downloaded, then still inside the add-ons section, look for "Sims 2 GMDC Tools" and activate it by clicking the checkbox.


Scene Structure
The imported scene consists of an empty container object, one or more mesh objects and on rigged meshes an armature object.


How to Use
Import a GMDC file, either through the newly added UI panel or the Import/Export menu.
Make any edits you want to make, taking note of the information below.

Morphs
Editing of morphs is done through shape keys, you can either manually add them through the shape keys panel or by clicking 'Add Morph' inside the add-on's panel.
I recommend adding morphs through the add-on's panel as this will ensure proper naming.
As an added note to working with morphs, make sure all shape keys have the same order on every group.
For example, if one mesh has this order: [0] base [1] botmorphs, pregbot [2] botmorphs, fatbot, make sure every other mesh follows this order. I may implement a feature to automate this in the future.

Rigged meshes
Before exporting a rigged mesh, make sure to limit and normalize all bone weights.
First, make sure to limit the amount of bone weights to 4.
This can be done by selecting an object, pressing spacebar, typing 'limit' and selecting 'Limit number of Weights per Vertex' and setting the limit to 4.
After that you'll want to normalize all weights.
This can be done by selecting an object, pressing spacebar, typing 'normalize' and selecting 'Normalize All Vertex Groups'.

If you're working with a bodyshop mesh, you can apply a neck fix to all required objects. This will prevent sharp lines in a sim's neck.

Hard edges can be defined with marking them as sharp, the exporter will then make sure to split the edges when required.

Exporting
To export your finished mesh, select either the container object or anything inside it from the hierarchy.
With the aforementioned selected, click export from the menu or the add-on's panel and save.
Then simply continue as if you were using Milkshape.

GITHUB LINK

I hope someone finds it useful.