[osg-users] Up to date tutorials for linux

[Robert Osfield]

Hi Rodrigo,

On 2 March 2017 at 13:47, Rodrigo Dias <rodrigo1406 at gmail.com> wrote:
>> Building under linux/unix is explained in the OpenSceneGraph/README
>
> Right. But you also has a link at Documentation | Platform Specific | Linux. I thought everything platform specific would be there,

There isn't really anything platform specific about building under
Linux, it's just standard cross platform cmake and make usage :-)

This page could do will filling out, and the main Getting Started
section could do with filling out a bit.

> So what I did was to install OSG in a fresh Debian install in VirtualBox (at least to learn how it's done -- should have done that before). I've had a few problems:
>
> 1. As I told above, the Linux Platform Specifics menu could include the cmake commands from the README.
> 2. I needed to do make install_ld_conf after cmake . and before make. This could be in the manual as well, because I wasn't sure if it was the moment to do it. Luckily, it was.
> 3. After I built everything, I came to "Running the examples", and only then I've been told to use -DBUILD_OSG_EXAMPLES=1 with cmake. I tried running cmake again, and got the following results:
>
>
> Code:
> rods at debianVB:~/Downloads/OSG-3.4.0$ cmake . -DBUILD_OSG_EXAMPLES=1
> -- checking for module 'gta'
> --   package 'gta' not found
> -- Could NOT find GStreamer (missing:  GSTREAMER_INCLUDE_DIRS GSTREAMER_LIBRARIES GSTREAMER_VERSION GSTREAMER_BASE_INCLUDE_DIRS GSTREAMER_BASE_LIBRARIES GSTREAMER_APP_INCLUDE_DIRS GSTREAMER_APP_LIBRARIES GSTREAMER_PBUTILS_INCLUDE_DIRS GSTREAMER_PBUTILS_LIBRARIES)
> -- Could NOT find SDL2 (missing:  SDL2_LIBRARY SDL2_INCLUDE_DIR)
> -- Could NOT find SDL (missing:  SDL_LIBRARY SDL_INCLUDE_DIR)
> -- checking for module 'gtk+-2.0'
> --   package 'gtk+-2.0' not found
> -- checking for module 'gtkglext-x11-1.0'
> --   package 'gtkglext-x11-1.0' not found
> -- Could NOT find FLTK (missing:  FLTK_LIBRARIES FLTK_FLUID_EXECUTABLE)
> -- Found GLUT: /usr/lib/i386-linux-gnu/libglut.so
> -- Could NOT find wxWidgets (missing:  wxWidgets_FOUND)
> -- checking for module 'xrandr'
> --   package 'xrandr' not found
> CMake Error at /usr/share/cmake-3.0/Modules/Qt4Macros.cmake:138 (file):
>   file Internal CMake error when trying to open file:
>   /home/rods/Downloads/OSG-3.4.0/src/osgQt/__/__/include/osgQt/moc_QGraphicsViewAdapter.cxx_parameters
>   for writing.
> Call Stack (most recent call first):
>   /usr/share/cmake-3.0/Modules/Qt4Macros.cmake:177 (QT4_CREATE_MOC_COMMAND)
>   src/osgQt/CMakeLists.txt:20 (QT4_WRAP_CPP)
>
> -- Configuring incomplete, errors occurred!
> See also "/home/rods/Downloads/OSG-3.4.0/CMakeFiles/CMakeOutput.log".
> See also "/home/rods/Downloads/OSG-3.4.0/CMakeFiles/CMakeError.log".
> CMake Error: Unable to open check cache file for write. /home/rods/Downloads/OSG-3.4.0/CMakeFiles/cmake.check_cache

It looks like there is an error relating to the osgQt module/cmake's
Qt4Macros.  Either Cmake or Qt might have changed since we made the
3.4.0 (a year and half ago.), or perhaps debian's combination of these
wasn't tested during the OSG-3.4.0 testing cycle.

Could you try the master from github?

Or just disable the build of osgQt by setting QT4_FOUND and
Qt5Widgets_FOUND to FALSE via cmake.

> I don't know if it's only here, or only in Debian, but probably some other advices could be included in the installation guide to avoid all this.

We can't provide guidance on issues we haven't seen before, the above
issues aren't standard ones.  I've just pulled down 3.4.0 onto my
Kubuntu 16.04 system and it's building cleanly.


> Other thing, the lines below are wrong. You cannot have a space between the variable name, the equal sign and the variable value.
>
> export PATH = ${PATH}:/home/myaccount/OpenSceneGraph/bin
> export LD_LIBRARY_PATH = ${LD_LIBRARY_PATH}:/home/myaccount/OpenSceneGraph/lib
> export OSG_FILE_PATH = /home/myaccount/OpenSceneGraph-Data:/home/myaccount/OpenSceneGraph-Data/Images
>
> They should be
>
> export PATH=${PATH}:/home/myaccount/OpenSceneGraph/bin
> export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:/home/myaccount/OpenSceneGraph/lib
> export OSG_FILE_PATH=/home/myaccount/OpenSceneGraph-Data:/home/myaccount/OpenSceneGraph-Data/Images

Where is the above?

> Still another thing, the menu Documentation | Tutorials show only one tutorial "Analysing a Scenegraph". I think that 20 tutorials 8-years-old are not so bad to be thrown away like that, are they?

This is why we've kept around the old tracs.openscenegraph.org
website.  We ported over most of the website to Joomla a few years
back but there are bits that we haven;'t had a chance to port across.
Please realize that this work is being done in peoples free time,
there isn't a rich sugar daddy that goes around spreading pixie dust
to magic things to happen, it takes hard graft in between all the rest
of our work.

Robert.