CMake: how to set VTK_DIR?

Question

This is one part of my CMakeLists.txt

set (VTK_DIR "/usr/include/vtk-5.8")

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})
IF(VTK_FOUND)
  message("found VTK. Version:" ${VTK_VERSION}. VTK_DIR: ${VTK_DIR})
ELSE(VTK_FOUND)
  MESSAGE(FATAL_ERROR
    "Cannot build the executable without VTK. Please set the                                                                                                   
VTK_DIR")
ENDIF(VTK_FOUND)

cmake . tells me:

found VTK. Version:6.0.0.VTK_DIR:/usr/local/lib/cmake/vtk-6.0

Giving the VTK_DIR in the command line does not help either:

cmake -DVTK_DIR:PATH=/usr/include/vtk-5.8 .

Still cmake looks in /usr/local/lib/cmake/vtk-6.0 for VTK.

What is wrong here?

Solution

VTK_DIR is a cache variable, which keeps its state across CMake invocations. You can set it from the command line, or via one of the CMake GUI interfaces.

Or, if you're certain you want to force it from your CMake file itself, you can use this syntax:

SET(VTK_DIR "/usr/include/vtk-5.8" CACHE PATH "VTK directory override" FORCE)

Comments

[Tengis]

Well my VTK-header are not there, where cmake expect them. Normally I should be able to precise in the command line (or the GUI-windows) the directory where cmake should look for the header-files. Your solution does not work for me. I also tried desperatly: set (VTK_INCLUDE_DIRS "/usr/include/vtk-5.8" CACHE PATH "VTK directory override" FORCE), but without success

[Peter]

I'm afraid the only thing remaining is to debug the FindVTK.cmake module. Add some MESSAGE() outputs so you can see what it's doing to find VTK.