As I understand it, the data used to display models in-game has been specially prepared for quick, efficient use by the game engine, then compressed into specialized files, typically with the .upk extension.
In order to get them to a state usable by 3D animation software such as SFM, other software is required to extract the separate components of the model (meshes, textures, et cetera), which are then reassembled in a way that SFM can understand. On a side note, this typically involves throwing away some of the finer components of the 3D model, thanks to the limitations of the Source engine.
What hungrypot is saying is that the tools haven’t been updated to understand the newer format Battleborn is using, so the content can’t be extracted.
Furthermore, extracting and manipulating said content is technically illegal. While you possess the right to play the Battleborn until you pass out, manipulating the content outside of the game engine is against the terms you agreed upon when installing the game, even if you’re not doing it for profit.
Of course, lots of things that could technically be deemed illegal are prolific on the internet, such as fanart. There’s a delicate relationship between content creators and fans, so the cease and desist letters only seem to get sent out when fans are perceived as being disrespectful of the characters, and/or when they use the imagery for profit–i.e. the Overwatch scenario.
But even that brouhaha was short-lived, most likely because the amount of money SFM animators are pulling in via Patreon pales in comparison to the amount it would cost to put a definitive legal stop to their actions. Blizzard would also be tried in the Court of Public Opinion, resulting in a verdict that they are mean ol’ buzzkill bullies and poop heads.
I can see it from both sides. Fans love having a digital toybox of action figures to manipulate, and game data extraction is the gateway to modding, which can be beneficial. Manipulating professional model work can also be an excellent learning tool.
On the other hand, these models are something the game’s developers have spent years of their lives bringing to life, from early design stages to meticulous rigging and texturing. Fans that extract that stuff and say “mine, now” are flirting with severe levels of disrespect, especially when they make questionable modifications.
For example, imagine if someone found a way to make an exact copy of the Mona Lisa using any computer, down to the brush stroke. They decide to paint over her body to make it look like she is wearing a string bikini, hang it in a gallery near the Louvre, and go around telling everyone they have improved the painting by making it sexier. Then, when politely asked to take the painting down, they claim their right to display it is protected by laws regarding fair use and parody.
Brave new world.