The extremely helpful guidelines posted at http://www.vtk.org/Wiki/Cocoa_VTK and via the readme file by Sean McBride and Mike Jackson inside the VTK repo were slightly out of date for VTK 6.1. So in case this helps anybody, I'm posting instructions for installing VTK 6.1 on OSX 10.8 with support for the SimpleCocoaVTK Xcode project.
* Installing VTK 6.1 for OSX 10.8 with Cocoa support *
These instructions slightly modify Ryan Glover's instructions at http://www.vtk.org/Wiki/Cocoa_VTK and the README.rtf in the VTK/Examples/GUI/Cocoa/Documentation folder by Sean McBride and Mike Jackson.
Clone the VTK git repo into a directory of your choice:
cd /Users/you/
git clone https://github.com/Kitware/VTK.git
cd VTK
git checkout tags/v6.1.0
make a build directory
mkdir VTKBuild
cd VTKBuild
Run the VTK cmake script
cmake ..
Edit lots of lines in the newly generated CMakeCache.txt (in the current VTKBuild directory). One issue I had was that there were error if I didn't use a full path for the CMAKE_INSTALL_PREFIX. So make sure to use "/Users/you/" instead of "~":
CMAKE_INSTALL_PREFIX:PATH=/Users/you/VTK/VTKBuild
BUILD_SHARED_LIBS:BOOL=OFF
CMAKE_BUILD_TYPE:STRING=Debug
VTK_USE_SYSTEM_ZLIB:BOOL=ON
CMAKE_OSX_ARCHITECTURES:STRING=i386;x86_64
CMAKE_OSX_SYSROOT:STRING=/Applications/XCode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk
Compile the VTK project (this might take over an hour to run!):
make
Copy headers to an include directory:
make install
VTK should now be completely installed in the VTKBuild directory and ready to use in an XCode project!
Go to your finder, navigate to Users/you/VTK/Examples/GUI/Cocoa/ and double click to open SimpleCocoaVTK.xcodeproj in XCode.
In the XCode menubar (at the top of the screen) Go to Preferences->Locations->Source Trees and use the + button to add in two source trees:
vtk-debug-include vtk-debug-include Users/you/VTK/VTKBuild/include/vtk-6.1
vtk-debug-lib vtk-debug-lib Users/you/VTK/VTKBuild/lib
Click on the XCode project and delete all the references to vtk 6.0:
In the project view, select Targets->SimpleCocoaVTK and then press "Build Phases" and then open the "Link Binary With Libraries". Delete all the files that begin with "libvtk" and end with "6.0.a"
In the file view of the SimpleCocoaVTK project, hightlight and delete all the files in the vtk-libraries folder.
Make sure the XCode file view is active. Then in the finder, navigate to /Users/you/VTK/VTKBuild/lib, and select all the files that begin with "libvtk" and end with "6.1.a". Drag these files into the folder "vtk-libraries" in the XCode file view.
In XCode, do a Product->Clean
You can now build and run the sample SimpleCocoaVTK project.