How to include PHP files that require an absolute path?

I have a directory structure like the following;
script.php
inc/include1.php
inc/include2.php
objects/object1.php
objects/object2.php
soap/soap.php
Now, I use those objects in both script.php and /soap/soap.php, I could move them, but I want the directory structure like that for a specific reason. When executing script.php the include path is inc/include.php and when executing /soap/soap.php it's ../inc, absolute paths work, /mnt/webdev/[project name]/inc/include1.php... But it's an ugly solution if I ever want to move the directory to a different location.
So is there a way to use relative paths, or a way to programically generate the "/mnt/webdev/[project name]/"?

Answer :

This should work
$root = realpath($_SERVER["DOCUMENT_ROOT"]);

include "$root/inc/include1.php";

Edit: added imporvement by aussieviking

source :http://stackoverflow.com/questions/4369/how-to-include-php-files-that-require-an-absolute-path