### 1.1.2 What is POV-Ray for Unix?

POV-Ray for Unix is essentially a version of the POV-Ray rendering engine prepared for running on a Unix or Unix-like operating system (such as GNU/Linux). It contains all the features of POV-Ray described in chapters 2 and 3 of the documentation, plus a few others specific to Unix and GNU/Linux systems. These additional features do not affect the core rendering code. They only make the program suitable for running under an Unix-based system, and provide the user with Unix-specific displaying capabilities. For instance, POV-Ray for Unix can use the X Window System to display the image it is rendering. On GNU/Linux machines, it can also display the image directly on the console screen using the SVGA library.

POV-Ray for Unix uses the same scheme as the other supported platforms to create ray-traced images. The POV-Ray input is platform-independant, as it is using text files (POV-Ray scripts) to describe the scene: camera, lights, and various objects. An extensive discussion of the POV-Ray Scene Description Language can be found elsewhere in this documentation.

#### 1.1.2.1 ... And What Is It Not?

POV-Ray for Unix is not a modeller. It will not let you design scenes graphically on-screen. There are several shareware and freeware programs available for this purpose. To write or modify POV-Ray scenes you just edit the actual text file containing the commands.

New users might be surprised to learn that, although this sounds primitive, it is in fact one of the things that gives POV-Ray so much power and flexibility. There are many other rendering programs that give you a point-and-click interface, but when it comes down to absolute control of your scene, it's hard to beat a text-based scene description language (even though it's harder for some to learn).