Undefined reference aiImportfile (assimp) using QT

Question

I have bee trying to get assimp running in QT 5.2 in order to import some 3D objects, but Im having a problem with (I believe) the linker.

I installed it via cmake, first downloading the source files from here http://sourceforge.net/projects/assimp/files/assimp-3.0/, then using cmake to compile and install.

Then, I have tried to run the example they provide in the documentation

#include <assimp/cimport.h>        // Plain-C interface
#include <assimp/scene.h>          // Output data structure
#include <assimp/postprocess.h>    // Post processing flags

bool DoTheImportThing( const char* pFile)
{
  // Start the import on the given file with some example postprocessing
  // Usually - if speed is not the most important aspect for you - you'll t
  // probably to request more postprocessing than we do in this example.
  const aiScene* scene = aiImportFile( pFile,
                                      aiProcess_CalcTangentSpace       |
                                      aiProcess_Triangulate            |
                                      aiProcess_JoinIdenticalVertices  |
                                      aiProcess_SortByPType);
  // If the import failed, report it
  if( !scene)
  {
   // DoTheErrorLogging( aiGetErrorString());
    return false;
  }


  return true;
}

But when trying to compile this piece of code, I get the error

 error: undefined reference to `aiImportFile'
 error: collect2: error: ld returned 1 exit status

I am using a 32 bit linux mint. Does anybody have any idea why is it not linking? Should I have compiled with cmake using a specific flag? i havent been able to found any special flags in any posts around.

Thanks!

Answer 1

I finally solved it! Apparently, QT has a tool for importing external libraries. I just had to right click on the project, click add library, and add the file located at /user/local/libassimp.a

This added the following lines to my .pro file:

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/../../../../../usr/local/lib/release/ -lassimp
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/../../../../../usr/local/lib/debug/ -lassimp
else:unix: LIBS += -L$$PWD/../../../../../usr/local/lib/ -lassimp

INCLUDEPATH += $$PWD/../../../../../usr/local/include
DEPENDPATH += $$PWD/../../../../../usr/local/include

win32-g++:CONFIG(release, debug|release): PRE_TARGETDEPS += $$PWD/../../../../../usr/local/lib/release/libassimp.a
else:win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/../../../../../usr/local/lib/debug/libassimp.a
else:win32:!win32-g++:CONFIG(release, debug|release): PRE_TARGETDEPS += $$PWD/../../../../../usr/local/lib/release/assimp.lib
else:win32:!win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/../../../../../usr/local/lib/debug/assimp.lib
else:unix: PRE_TARGETDEPS += $$PWD/../../../../../usr/local/lib/libassimp.a

Theres possibly a more elegant way of coding that, but at least it worked.