I'm looking for a solution to open AutoCAD file in the web. For example something to convert an DWG into PNG when requested by a PHP file. There is no need to edit the file, but instead show a preview of the file or convert it and create a thumbnail.
This need to work with CodeIgniter and PHP, and should run independent of the system (doesn't require to install nothing or have access to the root's server).
It can be however a java or using C. Please let me know your solutions.