Reference:Notation and Basic Assumptions

Throughout the tutorial and reference books, a consistent notation is used to mark keywords of the scene description language, command line switches, INI file keywords and file names.

For example:

Scene description language keywords and command-line switches:

• sphere, 4.0 * sin(45.0)
• +W640 +H480

Syntax, optional syntax, multiple syntax, and zero or more syntax items allowed respectively:

• SYNTAX_ITEM
• [SYNTAX_ITEM]
• SYNTAX_ITEM...
• [SYNTAX_ITEM...]

A float value or expression, and a vector value or expression:

• Value_1
• <Value_1>

Alternatives are represented by a vertical bar between syntax items; exactly one of the listed items must be present:

• ITEM1 | ITEM2 | ITEM3

Arbitrary order is represented by an ampersand between syntax items:

• ITEM1 & ITEM2 & ITEM3

Fixed order is represented by simple juxtaposition of syntax items:

• ITEM1 ITEM2 ITEM3

The above notations can also appear in various combinations; parentheses are used to resolve ambiguities. For instance, the following notation would indicate that the optional items ITEM1 and ITEM2, as well as either ITEM3A or ITEM3B, may appear in any order:

• [ITEM1] & [ITEM2] & (ITEM3A | ITEM3B)

Note: The ampersand notation to denote arbitrary order is just being phased in; some syntax descriptions may still use juxtaposition, regardless of whether the order of items is irrelevant or not; please be aware that those are (or at least should be) exceptions.

Certain lists and arrays also require square braces as part of the language rather than the language description:

• [ ITEM ]

Note: POV-Ray is a command-line program on Unix and other text-based operating systems and is menu-driven on Windows and Macintosh platforms. Some of these operating systems use folders to store files while others use directories. Some separate the folders and sub-folders with a slash character (/), back-slash character (\), or others.

We have tried to make this documentation as generic as possible but sometimes we have to refer to folders, files, options etc. and there is noway to escape it. Here are some assumptions we make...

1. You installed POV-Ray in the C:\POVRAY36 directory. For MS-Dos this is probably true but for Unix it might be /usr/povray3, or for Windows it might be C:\Program Files\POV-Ray for Windows v3.6, for Mac it might be MyHD:Apps:POV-Ray 36:, or you may have used some other drive or directory. So if we tell you that Include files are stored in the \povray36\include directory, we assume you can translate that to something like::POVRAY36:INCLUDE or C:\Program Files\POV-Ray for Windows v3.6\include or whatever is appropriate for your platform, operating system and installation.
2. POV-Ray uses INI files and/or command-line switches (if available) to choose options in all versions, but Windows and Mac also use dialog boxes or menu choices to set options. We will describe options assuming you are using switches or INI files when describing what the options do. We have taken care to use the same terminology in designing menus and dialogs as we use in describing switches or INI keywords. See your version-specific documentation on menu and dialogs.
3. Some of you are reading this using a help-reader, built-in help,web-browser, formatted printout, or plain text file. We assume you know how to get around in which ever medium you are using. We will say See the chapter on Setting POV-Ray Options we assume you can click, scroll, browse, flip pages or whatever to get there.