I'm very sorry for the necroposting, but it looks like the .bin files are actually splits of the file system (as long as you can see strings like "ftypnrfi"). If you were looking for models, textures or sound, have you tried looking for "NDP3", "NTP3" or "NUS" within the bin files of the Wii U version?
I've only looked into the arcade version (PS3 based) and Xbox 360 version so far. I'm skipping the Xbox 360 method since Smash Forge fails to load them. I used a binary file splitter (
csplitb.py in my case) and with the hex "4E445033" (NDP3) to split. Once it split out the NDP3 files with the .nud extension appended, I opened up the model in Smash Forge and it successfully loads the model. Below is an image of the model of loaded on Smash Forge, I had the texture extracted too which is why it is textured.
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The NDP3 (model), NTP3 (texture) format is also used in Smash Wii U, so I don't suppose the model format would be similar with the Wii U version?
Miscellaneous notesThe NU Engine has a sort of naming scheme to their models and textures headers, ND(XX) and NT(XX) respectively where the (XX) varies depending on platform but data type remains mostly the same (with some exception like the Xbox ones).
The (XX) can be as :
P3 - Mainly PS3 (also Wii U and some PC ports)
XR - Xbox
LX - Linux
WD- Windows
EDIT: I was told that the Wii U version uses NDP3 headers too, though I don't have the files to research yet.
EDIT 2 : Checked the Wii U files and they are indeed encrypted in some way, only ram dumping from an emulator works atm.