VTK 9.5.0 WebAssembly 64-bit build fails with BigInt conversion error

Support
1

Hello, I’m trying to build VTK 9.5.0 with WebAssembly 64-bit support following the official documentation, but I’m encountering a BigInt conversion error during the build process.

Special Note: Initially, the build was using Emscripten’s bundled Node.js, so I modified the .emscripten file to point to my system’s Node.js v23.8.0 instead.

Environment:

  • VTK: 9.5.0
  • CMake: 3.31
  • Emscripten: 4.0.3
  • Node.js: v23.8.0
  • OS: Windows 11
  • Build system: Ninja

Build Configuration:

bash

emcmake cmake \
    -S .. \
    -B . \
    -G "Ninja" \
    -DCMAKE_BUILD_TYPE=Release \
    -DBUILD_SHARED_LIBS:BOOL=OFF \
    -DVTK_WEBASSEMBLY_THREADS:BOOL=ON \
    -DVTK_WEBASSEMBLY_EXCEPTIONS:BOOL=ON \
    -DVTK_WEBASSEMBLY_64_BIT:BOOL=ON

Error: During the build, when trying to generate the wrap hierarchy for VTK::CommonCore, I get:

[1134/4962] Generating the wrap hierarchy for VTK::CommonCore
FAILED: lib/vtk-9.5/hierarchy/VTK/vtkCommonCore-hierarchy.txt
...
TypeError: Cannot convert a BigInt value to a number
    at Object. (D:\dev\vtk-07-08\VTK-9.5.0\build\bin\vtkWrapHierarchy-9.5.js:1:6880)
    at Module._compile (node:internal/modules/cjs/loader:1734:14)
    ...
Node.js v23.8.0

The build system is trying to run vtkWrapHierarchy-9.5.js with Node.js using the --experimental-wasm-memory64 flag, but it fails with a BigInt conversion error.

Question: Is this a known issue with VTK 9.5.0’s WebAssembly 64-bit build? The documentation mentions 64-bit support, but it seems the build tools themselves have issues running in 64-bit mode. Should the build tools (like vtkWrapHierarchy) be compiled in 32-bit mode while keeping the actual VTK libraries in 64-bit?

Any guidance would be greatly appreciated. Thank you!

2

Please use node >= 24.0.0. See Building VTK | VTK.wasm for a complete guide.

1 Like
3

Thank you so much! I really appreciate your help.

5

Thank you for your guidance - I successfully built VTK with 64-bit following your instructions. I really appreciate your help. However, when I tried to build the cone example, I encountered an issue.

I successfully configured the build using emcmake with these flags:

-DCMAKE_C_FLAGS="-sMEMORY64" -DCMAKE_CXX_FLAGS="-sMEMORY64"

But when I run cmake --build build, I get the following error. How can I resolve this?

PS D:\dev\vtk-07-09\Examples\Emscripten\Cxx\HsCone> cmake --build build
[1/1] Linking CXX executable D:\dev\vtk-07-09\Examples\docs\public\demo\cpp-app-1\main.js
FAILED: D:/dev/vtk-07-09/Examples/docs/public/demo/cpp-app-1/main.js
C:\WINDOWS\system32\cmd.exe /C "cd . && D:\dev\vtk-07-09\emsdk\upstream\emscripten\em++.bat -sMEMORY64 -g -lembind -sALLOW_MEMORY_GROWTH=1 -sSINGLE_FILE=1 -sASSERTIONS=1 -O0 -g3 -fwasm-exceptions -sEXCEPTION_STACK_TRACES=1 -pthread -sMEMORY64=1 -sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE=$getWasmTableEntry --js-library=D:/dev/vtk-07-09/installRelease/lib/vtkWebAssemblyRenderWindowInteractor.js --js-library=D:/dev/vtk-07-09/installRelease/lib/vtkEmscriptenTestUtilities.js --use-port=emdawnwebgpu -s FULL_ES3=1 -s MIN_WEBGL_VERSION=2 -s MAX_WEBGL_VERSION=2 @CMakeFiles\main.rsp -o D:\dev\vtk-07-09\Examples\docs\public\demo\cpp-app-1\main.js && cd ."
em++: warning: -pthread + ALLOW_MEMORY_GROWTH may run non-wasm code slowly, see https://github.com/WebAssembly/design/issues/1271 [-Wpthreads-mem-growth]
error: handleI64Signatures: signature too long for emwgpuWaitAny
Error: Aborting compilation due to previous errors
em++: error: ''C:\Users\User\AppData\Local\fnm_multishells\28136_1752129150499\node.EXE' 'D:\dev\vtk-07-09\emsdk\upstream\emscripten\tools\compiler.mjs' -' failed (returned 1)
ninja: build stopped: subcommand failed.