Hi,
Undefined symbols have multiple causes. Can you please post some of the error messages? I’ve successfully built VTK 8.2 with MinGW64 before. Compiling VTK with MinGW64 is addressed in the manual of my project: gammaray/GammaRayManual.docx at master · PauloCarvalhoRJ/gammaray · GitHub (refer to Sections 2.4.6 and 2.4.7). Alternativelly, you can download precompiled VTK libraries with the MSYS2 environment. There, you can do a pacman -S mingw-w64-x86_64-vtk to get the VTK libraries compiled with MinGW64 (luckily, their latest version is 8.2.0-1). Usage of MSYS2 for dependency management (not only VTK) is covered by section 2.2 of that manual.
I hope this helps,
Paulo