I've just committed Sonic Adventure Tools, a group of C# projects for working with Sonic Adventure and its derivatives (SADX, SADXPC). The main project here is SADXPCDecompiler, which extracts data from a DLL and generates a bunch of .c code files with the data contained in the DLL. The files that can be compiled to regenerate the DLL. As a matter of a fact, I've also committed the code files for CHRMODELS.DLL in Sonic Adventure DX PC Decompilation. The game will happily use the new DLL if you replace it in SADX's installation folder. If you find problems with the new DLL, please post in this thread. The other projects in Sonic Adventure Tools are class libraries that could be used in other programs such as editors.