1. Go to this page and download the library: Download php3d/stl library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
php3d / stl example snippets
use php3d\stl\STL;
use php3d\stl\STLFacetNormal;
$stl = STL::fromString(file_get_contents("/path/to/file.stl"));