Building Qt 4.8.5 for Maya 2015 on Linux


Overview
--------
Maya uses a customized version of Nokia's Qt libraries. If you want to
write Maya plug-ins which also make use of Qt you will have to build Qt
from the modified source files provided in this directory and link your
plug-ins against those libraries.

qt-adsk-4.8.5.tgz contains the modified Qt source code, in tarred, gzipped
form.

adsk-qt485-patch.txt contains the customizations to the standard Qt source,
in standard patch diff format. You do not need to apply the patch file as
the .tgz file already contains the changes. The patch file is just provided
for informational purposes.


Unpack The Archive
------------------
Unpack the archive using the following command:

    tar xzf qt-adsk-4.8.5.tgz

then step into the resulting directory:

    cd qt-adsk-4.8.5


OpenSSL
-------

Ensure that the openssl-devel   package is installed on the machine

    yum install openssl-devel



Configure
---------
To avoid problems with differences in compiler versions between Maya and
Qt, Qt should be built with the same versions of the compilers as are used
for building Maya plug-ins. Refer to the Maya API Guide for instructions on
how to set them up.

Regardless of the actual version of the compiler, though, the Qt mkspec
files expect them to be called 'gcc410' and 'g++410', so you may have to
set up appropriate links. For example, if Maya requires GCC version 4.1.2
and you've placed that in /opt/gcc412, as the API Guide recommends, then
you would have to set up links as follows:

	ln -s /opt/gcc412/bin/gcc412 /usr/bin/gcc410
	ln -s /opt/gcc412/bin/g++412 /usr/bin/g++410

Once the compilers are properly set up, configure the Qt build using the
following command:

    ./configure -separate-debug-info -stl -no-rpath -no-qt3support -plugin-sql-sqlite

The configuration process should end with the following message:

    Qt is now configured for building. Just run 'gmake'.
    Once everything is built, you must run 'gmake install'.
    Qt will be installed into /usr/local/Trolltech/Qt-4.8.5

    To reconfigure, run 'gmake confclean' and 'configure'.


Build
-----
Build the binaries using the following command:

    make -j 8 >& build.log

The '-j' flag instructs 'make' to use multiple processes, which can speed
up the build on multicore systems. For optimal results the value after '-j'
should be roughly double the number of cores on your system.


Install
-------
To perform the installation, make yourself superuser then execute the
following command:

    make install

By default Qt will be installed into /usr/local/Trolltech/Qt-4.8.5

Add the Qt 'bin' directory (e.g. /usr/local/Trolltech/Qt-4.8.5/bin) to the
start of your path.

The directory where you expanded the archive is no longer needed and may be
deleted if you wish to free up the space.


Build The devkit Qt Plug-ins
----------------------------
You can test your Qt installation by building the Qt plug-ins which ship
with Maya's devkit.

First, make sure that the 'qmake' command is in your path:

    which qmake

If you didn't change the install location for Qt then you should get back
the following:

    /usr/local/Trolltech/Qt-4.8.5/bin/qmake

If not, then you must add /usr/local/Trolltech/Qt-4.8.5/bin to the start of
your path.

Maya's Qt plug-ins can be built as follows:

1) Copy Maya's devkit/plug-ins directory to some place where you have write
privileges. E.g:

    cp -r /usr/autodesk/maya2014-x64/devkit/plug-ins ~/myPlugins

2) Move into that directory:

    cd ~/myPlugins

3) Execute the following command:

    make -f Makefile.qt 

4) Clean up unneeded intermediate files:

    make -f Makefile.qt clean


If in step 3 you get the following error message:

    Qt not found. Qt-based plug-ins will not be built.

that means that the 'qmake' command could not be found in your path.