Build Settings

VTK has a number of settings available for its build. The common variables to modify include:

• BUILD_SHARED_LIBS (default ON): If set, shared libraries will be built. This is usually what is wanted.

• VTK_USE_PCH (default ON): If set, VTK will use precompiled headers to speed up compilation.

• VTK_USE_CUDA (default OFF): Whether CUDA support will be available or not.

• VTK_USE_MPI (default OFF): Whether MPI support will be available or not.

• VTK_WRAP_PYTHON (default OFF; requires VTK_ENABLE_WRAPPING): Whether Python support will be available or not.

Less common, but variables which may be of interest to some:

• VTK_BUILD_EXAMPLES (default OFF): If set, VTK’s example code will be added as tests to the VTK test suite.

• VTK_ENABLE_LOGGING (default ON): If set, enhanced logging will be enabled.

• VTK_LOGGING_TIME_PRECISION (default 3; requires VTK_ENABLE_LOGGING): Change the precision of times output when VTK_ENABLE_LOGGING is on.

• VTK_BUILD_TESTING (default OFF): Whether to build tests or not. Valid values are OFF (no testing), WANT (enable tests as possible), and ON (enable all tests; may error out if features otherwise disabled are required by test code).

• VTK_ENABLE_KITS (default OFF; requires BUILD_SHARED_LIBS): Compile VTK into a smaller set of libraries. Can be useful on platforms where VTK takes a long time to launch due to expensive disk access.

• VTK_ENABLE_WRAPPING (default ON): Whether any wrapping support will be available or not.

• VTK_WRAP_JAVA (default OFF; requires VTK_ENABLE_WRAPPING): Whether Java support will be available or not.

• VTK_JAVA_RELEASE_VERSION (default 8; requires VTK_WRAP_JAVA): The version of Java in which VTK’s Java wrapping will be built for.

• VTK_WRAP_SERIALIZATION (default OFF; requires VTK_ENABLE_WRAPPING): Whether serialization code will be auto generated or not.

• VTK_BUILD_MAVEN_PKG (default OFF; requires VTK_WRAP_JAVA): Whether to build the Java Maven package for VTK.

• VTK_SMP_IMPLEMENTATION_TYPE (default Sequential): Set which SMPTools will be implemented by default. Must be either Sequential, STDThread, OpenMP or TBB. The backend can be changed at runtime if the desired backend has his option VTK_SMP_ENABLE_<backend_name> set to ON.

• VTK_ENABLE_CATALYST (default OFF): Enable catalyst-dependent modules including the VTK catalyst implementation. Depends on an external Catalyst.

• VTK_WEBASSEMBLY_64_BIT (default OFF): This option is applicable only when building with Emscripten toolchain. Adds -sMEMORY64 compiler and linker flags.

• VTK_WEBASSEMBLY_THREADS (default OFF): This option is applicable only when building with Emscripten toolchain. Adds -pthread compiler and linker flags. When VTK_BUILD_TESTING is ON, this also runs unit tests in web workers, which is the only way for the tests to reliably load data files without having to embed entire datasets inside the test binaries.

• VTK_WEBASSEMBLY_SMP_THREAD_POOL_SIZE (default 0, means runtime hardware concurrency): This option can be used for limiting the number of webassembly threads consumed by SMP tools. By setting this you can reserve threads for your application to use.

• VTK_WEBASSEMBLY_LEGACY_EXCEPTIONS (default ON): This option is applicable only when building with Emscripten toolchain. When ON, VTK is compiled with the legacy Wasm EH proposal, matching emscripten’s historical default (-sWASM_LEGACY_EXCEPTIONS=1). Set to OFF when the rest of the link — the consumer application and any other libraries — is built with -sWASM_LEGACY_EXCEPTIONS=0; the resulting binary then uses the standardized exception handling proposal end-to-end. Mixing both proposals causes the browser to reject the module at instantiate with “module uses a mix of legacy and new exception handling instructions”.

• VTK_TESTING_WASM_ENGINE (default ``): Path to a wasm runtime executable. This is used to run C++ tests in wasm environments.

• VTK_WRAP_JAVASCRIPT (default OFF; requires VTK_ENABLE_WRAPPING): Whether JavaScript support will be available or not.

• VTK_WASM_DEBUGINFO (default NONE): Extent of debug information in webassembly binaries when VTK_WRAP_JAVASCRIPT is ON. Controls the debug flags that allow the compiler to collect the debugging information. Must be either NONE, READABLE_JS, PROFILE or DEBUG_NATIVE.

• VTK_WASM_OPTIMIZATION (default SMALL): Optimization knobs for the webassembly binaries when VTK_WRAP_JAVASCRIPT is ON. Controls the optimization flags being used when running emcc. Must be either NO_OPTIMIZATION, LITTLE, MORE, BEST, SMALL, SMALLEST or SMALLEST_WITH_CLOSURE.

• VTK_WEBASSEMBLY_JOB_POOL_LINK_SIZE (default number of processors): Size of the job pool for linking wasm targets. Adjust as needed to avoid OOM errors.

OpenGL related build options:

When OpenGL is used, a valid rendering environment (e.g., X, Cocoa, OSMesa, EGL) must be available. Sanity checks are in place to prevent a broken build.

For specific platforms:

• Android: vtkEGLRenderWindow is the default.

• macOS: vtkCocoaRenderWindow is the default.

• iOS: vtkIOSRenderWindow is the default.

• WebAssembly: vtkWebAssemblyOpenGLRenderWindow is the default.

Please learn more about how you can influence the render window selection process in OpenGL

Additional Rendering related build options:

On Linux, the order of render window attempts is:

1. vtkXOpenGLRenderWindow

2. vtkEGLRenderWindow

3. vtkOSOpenGLRenderWindow

On Windows:

• vtkWin32OpenGLRenderWindow

• vtkOSOpenGLRenderWindow

By default, VTK automatically selects the most appropriate render window class at runtime. This selection process uses the Initialize method of the compiled subclass to test whether the chosen setup is valid. If the initialization succeeds, the corresponding render window instance is returned.

The default values of the following CMake VTK_OPENGL_HAS_* knobs are already configured so that the above condition is always met on all supported platforms.

• VTK_USE_COCOA (default ON; requires macOS): Use Cocoa for render windows.

• VTK_USE_X (default ON for Unix-like platforms except macOS, iOS, and Emscripten, OFF otherwise): Use X for render windows.

• VTK_OPENGL_USE_GLES (default OFF; forced ON for Android): Whether to use OpenGL ES API for OpenGL or not.

• VTK_OPENGL_HAS_EGL (default ON for Android and Linux, OFF otherwise): Use to indicate that the OpenGL library being used supports EGL context management.

• VTK_DEFAULT_EGL_DEVICE_INDEX (default 0; requires VTK_OPENGL_HAS_EGL): The default EGL device to use for EGL render windows.

• VTK_USE_WAYLAND_OPENGL (default OFF; requires VTK_OPENGL_HAS_EGL): Use Wayland as backend for EGL render windows instead of X.

• VTK_ENABLE_WEBGPU (default OFF; required if using Emscripten): Enable WebGPU rendering support.

• VTK_DEFAULT_RENDER_WINDOW_OFFSCREEN (default OFF): Whether to default to offscreen render windows by default or not.

• VTK_USE_OPENGL_DELAYED_LOAD (default OFF; requires Windows and CMake >= 3.13): If set, use delayed loading to load the OpenGL DLL at runtime.

• VTK_DEFAULT_RENDER_WINDOW_HEADLESS (default OFF; only available if applicable): Default to a headless render window.

• VTK_USE_WIN32_OPENGL (default ON for Windows, forced OFF otherwise): Use Win32 APIs for render windows (typically only relevant for OSMesa on Windows builds).

More advanced options:

• VTK_ABI_NAMESPACE_NAME (default <DEFAULT> aka ""): If set, VTK will wrap all VTK public symbols in an inline namespace <VTK_ABI_NAMESPACE_NAME> to allow runtime co-habitation with different VTK versions. Some C ABIs are also wrapped in this namespace using macro expansion #define c_abi VTK_ABI_NAMESPACE_MANGLE(c_abi)

• VTK_ABI_NAMESPACE_ATTRIBUTES (default <DEFAULT> aka ""): If set, VTK will inject these attributes into the inline namespace. i.e. inline namespace <VTK_ABI_NAMESPACE_ATTRIBUTES> <VTK_ABI_NAMESPACE_NAME> The VTK_ABI_NAMESPACE_ATTRIBUTES is only applied the the APIs inside of the namespace, not to C APIs.

• VTK_BUILD_DOCUMENTATION (default OFF): If set, VTK will build its API documentation using Doxygen.

• VTK_BUILD_SPHINX_DOCUMENTATION (default OFF): If set, VTK will build its sphinx documentation website.

• VTK_BUILD_ALL_MODULES (default OFF): If set, VTK will enable all modules not disabled by other features.

• VTK_ENABLE_REMOTE_MODULES (default ON): If set, VTK will try to build remote modules (the Remote directory). If unset, no remote modules will build.

• VTK_ENABLE_EXTRA_BUILD_WARNINGS (default OFF; requires CMake >= 3.19): If set, VTK will enable additional build warnings.

• VTK_ENABLE_EXTRA_BUILD_WARNINGS_EVERYTHING (default OFF; requires VTK_ENABLE_EXTRA_BUILD_WARNINGS and -Weverything support): If set, VTK will enable all build warnings (with some explicitly turned off).

• VTK_USE_EXTERNAL (default OFF): Whether to prefer external third party libraries or the versions VTK’s source contains.

• VTK_TARGET_SPECIFIC_COMPONENTS (default OFF): Whether to install files into target-specific components (<TARGET>-runtime, <TARGET>-development, etc.) or general components (runtime, development, etc.)

• VTK_VERSIONED_INSTALL (default ON): Whether to add version numbers to VTK’s include directories and library names in the install tree.

• VTK_CUSTOM_LIBRARY_SUFFIX (default depends on VTK_VERSIONED_INSTALL): The custom suffix for libraries built by VTK. Defaults to either an empty string or X.Y where X and Y are VTK’s major and minor version components, respectively.

• VTK_CUSTOM_LIBRARY_VERSION (default depends on VTK_VERSIONED_INSTALL): The custom version for libraries built by VTK. Defaults to either an empty string or X.Y where X and Y are VTK’s major and minor version if VTK_VERSIONED_INSTALL is ON.

• VTK_INSTALL_SDK (default ON): If set, VTK will install its headers, CMake API, etc. into its install tree for use.

• VTK_FORBID_DOWNLOADS (default OFF): If set, VTK will error on any network activity required during the build (namely remote modules and testing data).

• VTK_DATA_STORE (default is complicated): If set or detected, points to where VTK external data will be stored or looked up.

• VTK_DATA_EXCLUDE_FROM_ALL (default is complicated, but generally OFF): If set or detected, data downloads will only happen upon explicit request rather than through the build’s default target.

• VTK_RELOCATABLE_INSTALL (default ON): If set, the install tree will be relocatable to another path. If unset, the install tree may be tied to the build machine with absolute paths, but finding dependencies in non-standard locations may require work without passing extra information when consuming VTK.

• VTK_UNIFIED_INSTALL_TREE (default OFF): If set, the install tree is stipulated to be a unified install tree of VTK and all of its dependencies; a unified tree usually simplifies things including, but not limited to, the Python module paths, library search paths, and plugin searching. This option is irrelevant if a relocatable install is requested as such setups assume that dependencies are set up either via a unified tree or some other mechanism such as modules).

• VTK_ENABLE_SANITIZER (default OFF): Whether to enable sanitization of the VTK codebase or not.

• VTK_SANITIZER (default address; requires VTK_ENABLE_SANITIZER): The sanitizer to use.

• VTK_USE_LARGE_DATA (default OFF; requires VTK_BUILD_TESTING): Whether to enable tests which use “large” data or not (usually used to reduce the amount of data downloading required for the test suite).

• VTK_USE_HIP (default OFF; requires CMAKE >= 3.21 and NOT VTK_USE_CUDA) Whether HIP support will be available or not.

• VTK_LEGACY_REMOVE (default OFF): If set, VTK will disable legacy, deprecated APIs.

• VTK_LEGACY_SILENT (default OFF; requires VTK_LEGACY_REMOVE to be OFF): If set, usage of legacy, deprecated APIs will not cause warnings.

• VTK_USE_FUTURE_CONST (default OFF): If set, the VTK_FUTURE_CONST macro expands to const; otherwise it expands to nothing. This is used to incrementally add more const correctness to the codebase while making it opt-in for backwards compatibility.

• VTK_USE_FUTURE_BOOL (default OFF): If set, the vtkTypeBool typedef is defined to bool; otherwise it’s int. VTK was created before C++ even had bool, and so its oldest code used int. Set to ON to opt in to using more real bools, set to OFF only if required for backwards compatibility.

• VTK_USE_TK (default OFF; requires VTK_WRAP_PYTHON): If set, VTK will enable Tkinter support for VTK widgets.

• VTK_BUILD_COMPILE_TOOLS_ONLY (default OFF): If set, VTK will compile just its compile tools for use in a cross-compile build.

• VTK_NO_PYTHON_THREADS (default OFF): If set, then all Python threading in VTK will be disabled.

• VTK_PYTHON_FULL_THREADSAFE (default ON): If set, lock the Python GIL for Python C API calls, to make it safe to allow Python thread concurrency.

• VTK_SERIAL_TESTS_USE_MPIEXEC (default OFF): Used on HPC to run serial tests on compute nodes. If set, it prefixes serial tests with “${MPIEXEC_EXECUTABLE}” “${MPIEXEC_NUMPROC_FLAG}” “1” ${MPIEXEC_PREFLAGS}

• VTK_WINDOWS_PYTHON_DEBUGGABLE (default OFF): Set to ON if using a debug build of Python.

• VTK_WINDOWS_PYTHON_DEBUGGABLE_REPLACE_SUFFIX (default OFF): Set to ON to use just a _d suffix for Python modules.

• VTK_BUILD_PYI_FILES (default OFF): Set to ON to build .pyi type hint files for VTK’s Python interfaces.

• VTK_DLL_PATHS (default "" or VTK_DLL_PATHS from the environment): If set, these paths will be added via Python 3.8’s os.add_dll_directory mechanism in order to find dependent DLLs when loading VTK’s Python modules. Note that when using the variable, paths are in CMake form (using /) and in the environment are a path list in the platform’s preferred format.

• VTK_ENABLE_VR_COLLABORATION (default OFF): If ON, includes support for multi client VR collaboration. Requires libzmq and cppzmq external libraries.

• VTK_SMP_ENABLE_<backend_name> (default OFF if needs an external library otherwise ON): If set, builds with the specified SMPTools backend implementation that can be changed on runtime with VTK_SMP_BACKEND_IN_USE environment variable.

• VTK_USE_VIDEO_FOR_WINDOWS (default OFF; requires Windows): Enable the vtkAVIWriter class in the VTK::IOMovie module.

• VTK_USE_VIDEO_FOR_WINDOWS_CAPTURE (default OFF; requires Windows): Enable the vtkWin32VideoSource class in the VTK::IOVideo module.

• VTK_USE_MICROSOFT_MEDIA_FOUNDATION (default OFF; requires Windows): Enable the vtkMP4Writer class in the VTK::IOMovie module.

• VTK_USE_64BIT_TIMESTAMPS (default OFF; forced on for 64-bit builds): Build with 64-bit vtkMTimeType.

• VTK_USE_64BIT_IDS (default OFF for 32-bit builds; ON for 64-bit builds): Whether vtkIdType should be 32-bit or 64-bit.

• VTK_DEBUG_LEAKS (default OFF): Whether VTK will report leaked vtkObject instances at process destruction or not.

• VTK_DEBUG_RANGE_ITERATORS (default OFF; requires a Debug build): Detect errors with for-range iterators in VTK (note that this is very slow).

• VTK_ALWAYS_OPTIMIZE_ARRAY_ITERATORS (default OFF; requires NOT VTK_DEBUG_RANGE_ITERATORS): Optimize for-range array iterators even in Debug builds.

• VTK_ALL_NEW_OBJECT_FACTORY (default OFF): If ON, classes using vtkStandardNewMacro will use vtkObjectFactoryNewMacro allowing overrides to be available even when not explicitly requested through vtkObjectFactoryNewMacro or vtkAbstractObjectFactoryNewMacro.

• VTK_ENABLE_VISKORES_OVERRIDES (default OFF): If ON, enables factory override of certain VTK filters by their Viskores counterparts. There is also a runtime switch that can be used to enable/disable the overrides at run-time (on by default). It can be accessed using the static function viskoresFilterOverrides::SetEnabled(bool).

• VTK_GENERATE_SPDX (default OFF): If ON, SPDX file will be generated at build time and installed for each module and third party, in order to be able to create a SBOM. See SPDX files generation and SPDX & SBOM for more info.

• VTK_ANARI_ENABLE_NVTX (default OFF; requires CUDA Toolkit): If ON, enables the NVIDIA Tools Extension Library (NVTX) for profiling the ANARI rendering code and visualizing these events in tools like NSight Systems.

vtkArrayDispatch related options:

The VTK_DISPATCH_<array_type>_ARRAYS options (default OFF for all but AOS) enable the specified type of array to be included in a dispatch type list. Explicit arrays (such as AOS, SOA, Typed, and implicit arrays) are included in the vtkArrayDispatchTypeList.h The implicit array framework is included in the CommonCore module. The following array types currently exist for use with the VTK dispatch mechanism:

• VTK_DISPATCH_AOS_ARRAYS (default ON): includes dispatching for the commonly used “array-of-structure” ordered arrays derived from vtkAOSDataArrayTemplate

• VTK_DISPATCH_SOA_ARRAYS (default OFF): includes dispatching for “structure-of-array” ordered arrays derived from vtkSOADataArrayTemplate

• VTK_DISPATCH_AFFINE_ARRAYS (default OFF): includes dispatching for linearly varying vtkAffineArrays as part of the implicit array framework

• VTK_DISPATCH_CONSTANT_ARRAYS (default OFF): includes dispatching for constant arrays vtkConstantArray as part of the implicit array framework

• VTK_DISPATCH_STRIDED_ARRAYS (default OFF): includes dispatching for strided arrays vtkStridedArray as part of the implicit array framework

• VTK_DISPATCH_STRUCTURED_POINT_ARRAYS (default OFF): includes dispatching for structured point arrays vtkStructuredPointArray as part of the implicit array framework

Warning

Adding increasing numbers of arrays in the dispatch mechanism can greatly slow down compile times.

The VTK module system provides a number of variables to control modules which are not otherwise controlled by the other options provided.

• VTK_MODULE_USE_EXTERNAL_<name> (default depends on VTK_USE_EXTERNAL): Use an external source for the named third-party module rather than the copy contained within the VTK source tree.

  Warning

  Activating this option within an interactive cmake configuration (i.e. ccmake, cmake-gui) could end up finding libraries in the standard locations rather than copies in non-standard locations.

  It is recommended to pass the variables necessary to find the intended external package to the first configure to avoid finding unintended copies of the external package. The variables which matter depend on the package being found, but those ending with _LIBRARY and _INCLUDE_DIR as well as the general CMake find_package variables ending with _DIR and _ROOT are likely candidates.

  Example:

  ccmake -D HDF5_ROOT:PATH=/home/user/myhdf5 ../vtk/sources
  

• VTK_MODULE_ENABLE_<name> (default DEFAULT): Change the build settings for the named module. Valid values are those for the module system’s build settings (see below).

• VTK_GROUP_ENABLE_<name> (default DEFAULT): Change the default build settings for modules belonging to the named group. Valid values are those for the module system’s build settings (see below).

For variables which use the module system’s build settings, the valid values are as follows:

• YES: Require the module to be built.

• WANT: Build the module if possible.

• DEFAULT: Use the settings by the module’s groups and VTK_BUILD_ALL_MODULES.

• DONT_WANT: Don’t build the module unless required as a dependency.

• NO: Do not build the module.

If any YES module requires a NO module, an error is raised.