How to build vtk-wasm64


I am experimenting with >4GB limitation using vtk-wasm. However, I am getting error wasm32 object file can’t be linked in wasm64 mode. How do I compile vtk-wasm in wasm64 to test this?


Pass these extra args to cmake when configuring VTK.

That is sufficient to give you wasm64. Although, don’t be too excited. You will run into some issues with the SDL2 render window ¹. It was fixed in SDL3 but emscripten still uses SDL2.

Thanks! I was just curious about the build process. Passing the flags make it compiled, but the correct value is -sMEMORY64.

However, after compiling VTK WASM, I tried to build my app against the newly installed library, and got,

Could not find a configuration file for package "VTK" that is compatible
  with requested version "".

  The following configuration files were considered but not accepted:

    /scratch/tools/VTK/install-wasm-64/lib/cmake/vtk-9.3/vtk-config.cmake, version: 9.3.20240311 (64bit)

The same app and build script works with wasm 32-bit. I know wasm64 bit is still WIP. So, if you have any ideas how to proceed, it would be great. Otherwise, I just put off my experiment to wait for official release.


That happens because your project is trying to find 32-bit VTK wasm.

Pass those flags even when configuring your project.