Adding NextGEN Gallery directly into template PHP

Is it possible to insert a gallery directly into the code of my template, without using the wysiwyg editor?

I would like to add the gallery as part of the Loop, dynamically inserting it based on a Custom Field setting. Ideally, something such as
<?php nextgen_gallery(1); ?>

Does such a function exist?

http://wordpress.org/extend/plugins/nextgen-gallery/