### How data are organised in a file

The .rt file is a text file.

This is an example which describes the way data are subdivided:

{ section1

{ subsection1

attribute1 value;

}

attribute2 value;

}

{ section2

}

.

This file cannot be read by RT, it is only a template to show the highlight of the structure of a .rt file. The real identifiers used in a real .rt file are described after, with their meanings.

The parts of file separated by { and } are called sections. The file ends with a dot (.) .

The word after { is the type of the section.

A section can contain other sections ( called subsections ) or attribute.

A section contains some attributes. Every attribute has a value. The value depends on the attribute, name. The attribute values can be also subsection.

The attribute that can be in a section depends on the type of the section.

The sections describe things in the scene. The attributes tell how things are made. If a section needs the data of another one, the first one must follow the second.

Don' t worry if you don' t understand exactly, you will understand when you see the examples.