Use updated offscreen variables.
VTK_USE_OFFSCREEN
becomes VTK_DEFAULT_RENDER_WINDOW_OFFSCREEN
, and
VTK_USE_OFFSCREEN_EGL
becomes VTK_OPENGL_HAS_EGL
.
VTK_USE_OFFSCREEN
becomes VTK_DEFAULT_RENDER_WINDOW_OFFSCREEN
, and
VTK_USE_OFFSCREEN_EGL
becomes VTK_OPENGL_HAS_EGL
.