Runtime settings#

OpenGL#

On Linux and Windows, VTK will attempt to detect support for an OpenGL context backend at runtime and create an appropriate subclass of vtkOpenGLRenderWindow. You can override this process by specifying an environment variable VTK_DEFAULT_OPENGL_WINDOW. The possible values are:

  1. vtkXOpenGLRenderWindow (Linux; applicable only when VTK_USE_X is ON, which is the default setting)

  2. vtkWin32OpenGLRenderWindow (Windows; applicable only when VTK_USE_WIN32_OPENGL is ON, which is the default setting)

  3. vtkEGLRenderWindow (applicable only when VTK_OPENGL_HAS_EGL is ON, which is the default setting)

  4. vtkOSOpenGLRenderWindow (OSMesa, requires that osmesa.dll or libOSMesa.so is installed)

Note: VTK does not support OSMesa on macOS, iOS, Android and WebAssembly platforms.

Multisample anti-aliasing#

Some OpenGL drivers have rendering problems when Multisample anti-aliasing is enabled. It is possible to specify the environment variable VTK_FORCE_MSAA to troubleshoot rendering problems with these values:

  1. 0 to disable MSAA

  2. 1 to enable it regardless even when the driver is known to have problems with MSAA