Creating/modifying dynamic slide generators

This is just a basic explanation, you will need PHP knowledge to achieve, what you would like to do.

Here you can see, where to find the files of the generators, but this is the most important file from them, and probably you want to modify this one:
Joomla libraries/nextend2/smartslider/smartslider/plugins/generator/[generator main name]/[generator name]/generator.php
WordPress wp-content/plugins/nextend-smart-slider3 -pro/library/smartslider/plugins/generator/[generator main name]/[generator name]/generator.php
Magento app/code/community/Nextend2/SmartSlider3/library/magento/plugins/generator/[generator main name]/[generator name]/generator.php

You should go to the lower part of the file, to the _getData function because that is where the variables are getting the values. Check at its end, what is the variable it returns, usually, it's $data or $result. This is a multidimensional array which looks for example like this when getting its value:

$data[$i]['title'] = $products[$i]->name;

The $i is the index of the value in the array which is if you are using 1 variables / 1 slide, the number of the slide where it will be. The title is the name of the variable you will use in the backend, and on the right there is the value that will get this variable. This is either the result of a database query or the result of an api call. You will probably want to modify a database query. Check your database, find the extra table column you need or check the api what variables does it offer, var_dump this $result to see, what it is contains (you will need to click on Clear slider cache at your slider to see it), and give your new value to your new variable:

$data[$i]['newvar'] = $products[$i]->something_new;

After this you will be able to use the {|newvar-1|} variable in our backend.

Example

<?php
N2Loader::import('libraries.slider.generator.abstract', 'smartslider');

class N2Generatornewgeneratornewgenerator extends N2GeneratorAbstract
{
    protected function _getData($count, $startIndex) {
        $data = array();
        $data[0]['data'] = 'first data';
        $data[1]['data'] = 'second data';
        $data[2]['data'] = 'third data';
        return $data;
    }
}
If you want to make a new generator in Joomla, then check out this documentation, where you will see, how to make a system plugin, to not to have your generator overwritten by an update, and you will also find an example for the generator lower inside it.