# FindosgViewer

Finds the osgViewer library from the OpenSceneGraph toolkit.

Note

In most cases, it's recommended to use the `FindOpenSceneGraph` module instead and list osgViewer as a component. This will automatically handle dependencies such as the OpenThreads and core osg libraries:

    find_package(OpenSceneGraph COMPONENTS osgViewer)

This module is used internally by `FindOpenSceneGraph` to find the osgViewer library. It is not intended to be included directly during typical use of the `find_package()` command. However, it is available as a standalone module for advanced use cases where finer control over detection is needed. For example, to find the osgViewer explicitly or bypass automatic component detection:

    find_package(osgViewer)

OpenSceneGraph and osgViewer headers are intended to be included in C++ project source code as:

`example.cxx`

    #include <osg/PositionAttitudeTransform>
    #include <osgViewer/Viewer>
    // ...

When working with the OpenSceneGraph toolkit, other libraries such as OpenGL may also be required.

## Result Variables

This module defines the following variables:

`osgViewer_FOUND`

  Boolean indicating whether the osgViewer library of the OpenSceneGraph toolkit is found. For backward compatibility, the `OSGVIEWER_FOUND` variable is also set to the same value.

`OSGVIEWER_LIBRARIES`

  The libraries needed to link against to use osgViewer.

`OSGVIEWER_LIBRARY`

  A result variable that is set to the same value as the `OSGVIEWER_LIBRARIES` variable.

## Cache Variables

The following cache variables may also be set:

`OSGVIEWER_INCLUDE_DIR`

  The include directory containing headers needed to use osgViewer.

`OSGVIEWER_LIBRARY_DEBUG`

  The path to the osgViewer debug library.

## Hints

This module accepts the following variables:

`OSGDIR`

  Environment variable that can be set to help locate the OpenSceneGraph toolkit, including its osgViewer library, when installed in a custom location. It should point to the OpenSceneGraph installation prefix used when it was configured, built, and installed: `./configure --prefix=$OSGDIR`.

## Examples

Finding osgViewer explicitly with this module and creating an interface imported target that encapsulates its usage requirements for linking it to a project target:

    find_package(osgViewer)

    if(osgViewer_FOUND AND NOT TARGET osgViewer::osgViewer)
      add_library(osgViewer::osgViewer INTERFACE IMPORTED)
      set_target_properties(
        osgViewer::osgViewer
        PROPERTIES
          INTERFACE_INCLUDE_DIRECTORIES "${OSGVIEWER_INCLUDE_DIR}"
          INTERFACE_LINK_LIBRARIES "${OSGVIEWER_LIBRARIES}"
      )
    endif()

    target_link_libraries(example PRIVATE osgViewer::osgViewer)

## See Also

- The `FindOpenSceneGraph` module to find OpenSceneGraph toolkit.