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<strong class="NavBar">POV-Ray 3.6 for UNIX documentation</strong><br> <strong>3.2
Scene Description Language</strong>
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<h2><a name="s03_02">3.2 </a>Scene Description Language</h2>
<a name="s03_02_i1"><a name="s03_02_i2">
<p>
The reference section describes the POV-Ray <em>scene description language</em>. It is supposed to be used as a
reference for looking up things. It does not contain detailed explanations on how scenes are written or how POV-Ray is
used. It just explains all features, their syntax, applications, limits, drawbacks, etc.
</p>
<p>
The scene description language allows you to describe the world in a readable and convenient way. Files are created
in plain ASCII text using an editor of your choice. The input file name is specified using the <code> Input_File_Name</code>=<em>file</em>
option or <code>+I</code><em>file</em> switch. By default the files have the extension <code>.pov</code>. POV-Ray
reads the file, processes it by creating an internal model of the scene and then renders the scene.
</p>
<p>
The overall syntax of a scene is shown below. See "<a href="#l52">Notation and Basic Assumptions</a>" for
more information on syntax notation.
</p>
<pre>
SCENE:
SCENE_ITEM...
SCENE_ITEM:
LANGUAGE_DIRECTIVES |
camera { CAMERA_ITEMS... } |
OBJECTS |
ATMOSPHERIC_EFFECTS |
global_settings { GLOBAL_ITEMS }
</pre>
<p>
In plain English, this means that a scene contains one or more scene items and that a scene item may be any of the
five items listed below it. The items may appear in any order. None is a required item. In addition to the syntax
depicted above, a <em>LANGUAGE_DIRECTIVE</em> may also appear anywhere embedded in other statements between any two
tokens. There are some restrictions on nesting directives also.
</p>
<p>
For details on those five items see section "<a href="#l53">Language Directives</a>", section "<a href="#l54">Object</a>s",
section "<a href="#l55">Camera</a>", section "<a href="#l56">Atmospheric Effects</a>" and section
"<a href="#l57">Global Settings</a>" for details.
</p>
<p><strong>
Section Contents
</strong>
<ul>
<li>
<a href="s_97.html#s03_02_01">3.2.1 Language Basics</a>
<ul>
<li>
<a href="s_97.html#s03_02_01_01">3.2.1.1 Identifiers and Keywords</a>
<li>
<a href="s_97.html#s03_02_01_02">3.2.1.2 Comments</a>
<li>
<a href="s_97.html#s03_02_01_03">3.2.1.3 Float Expressions</a>
<ul>
<li>
<a href="s_97.html#s03_02_01_03_01">3.2.1.3.1 Literals</a>
<li>
<a href="s_97.html#s03_02_01_03_02">3.2.1.3.2 Identifiers</a>
<li>
<a href="s_97.html#s03_02_01_03_03">3.2.1.3.3 Operators</a>
<li>
<a href="s_97.html#s03_02_01_03_04">3.2.1.3.4 Functions</a>
<li>
<a href="s_97.html#s03_02_01_03_05">3.2.1.3.5 Built-in Constants</a>
<li>
<a href="s_97.html#s03_02_01_03_06">3.2.1.3.6 Built-in Variables</a>
</ul>
<li>
<a href="s_97.html#s03_02_01_04">3.2.1.4 Vector Expressions</a>
<ul>
<li>
<a href="s_97.html#s03_02_01_04_01">3.2.1.4.1 Literals</a>
<li>
<a href="s_97.html#s03_02_01_04_02">3.2.1.4.2 Identifiers</a>
<li>
<a href="s_97.html#s03_02_01_04_03">3.2.1.4.3 Operators</a>
<li>
<a href="s_97.html#s03_02_01_04_04">3.2.1.4.4 Operator Promotion</a>
<li>
<a href="s_97.html#s03_02_01_04_05">3.2.1.4.5 Functions</a>
<li>
<a href="s_97.html#s03_02_01_04_06">3.2.1.4.6 Built-in Constants</a>
</ul>
<li>
<a href="s_97.html#s03_02_01_05">3.2.1.5 Specifying Colors</a>
<ul>
<li>
<a href="s_97.html#s03_02_01_05_01">3.2.1.5.1 Color Vectors</a>
<li>
<a href="s_97.html#s03_02_01_05_02">3.2.1.5.2 Color Keywords</a>
<li>
<a href="s_97.html#s03_02_01_05_03">3.2.1.5.3 Color Identifiers</a>
<li>
<a href="s_97.html#s03_02_01_05_04">3.2.1.5.4 Color Operators</a>
<li>
<a href="s_97.html#s03_02_01_05_05">3.2.1.5.5 Common Color Pitfalls</a>
</ul>
<li>
<a href="s_97.html#s03_02_01_06">3.2.1.6 User-Defined Functions</a>
<ul>
<li>
<a href="s_97.html#s03_02_01_06_01">3.2.1.6.1 Sum and Product functions</a>
<li>
<a href="s_97.html#s03_02_01_06_02">3.2.1.6.2 Functions and Macros</a>
<li>
<a href="s_97.html#s03_02_01_06_03">3.2.1.6.3 Declaring User-Defined Float Functions</a>
<li>
<a href="s_97.html#s03_02_01_06_04">3.2.1.6.4 Declaring User-Defined Vector Functions</a>
<li>
<a href="s_97.html#s03_02_01_06_05">3.2.1.6.5 Declaring User-Defined Color Functions</a>
<li>
<a href="s_97.html#s03_02_01_06_06">3.2.1.6.6 Internal Pre-Defined Functions</a>
</ul>
<li>
<a href="s_97.html#s03_02_01_07">3.2.1.7 Strings</a>
<ul>
<li>
<a href="s_97.html#s03_02_01_07_01">3.2.1.7.1 String Literals</a>
<li>
<a href="s_97.html#s03_02_01_07_02">3.2.1.7.2 String Identifiers</a>
<li>
<a href="s_97.html#s03_02_01_07_03">3.2.1.7.3 String Functions</a>
</ul>
<li>
<a href="s_97.html#s03_02_01_08">3.2.1.8 Array Identifiers</a>
<ul>
<li>
<a href="s_97.html#s03_02_01_08_01">3.2.1.8.1 Declaring Arrays</a>
<li>
<a href="s_97.html#s03_02_01_08_02">3.2.1.8.2 Array Initializers</a>
</ul>
<li>
<a href="s_97.html#s03_02_01_09">3.2.1.9 Spline Identifiers</a>
<ul>
<li>
<a href="s_97.html#s03_02_01_09_01">3.2.1.9.1 Splines and Macros</a>
</ul>
</ul>
<li>
<a href="s_98.html#s03_02_02">3.2.2 Language Directives</a>
<ul>
<li>
<a href="s_98.html#s03_02_02_01">3.2.2.1 Include Files and the #include Directive</a>
<li>
<a href="s_98.html#s03_02_02_02">3.2.2.2 The #declare and #local Directives</a>
<ul>
<li>
<a href="s_98.html#s03_02_02_02_01">3.2.2.2.1 Declaring identifiers</a>
<li>
<a href="s_98.html#s03_02_02_02_02">3.2.2.2.2 #declare vs. #local</a>
<li>
<a href="s_98.html#s03_02_02_02_03">3.2.2.2.3 Identifier Name Collisions</a>
<li>
<a href="s_98.html#s03_02_02_02_04">3.2.2.2.4 Destroying Identifiers with #undef</a>
</ul>
<li>
<a href="s_98.html#s03_02_02_03">3.2.2.3 File I/O Directives</a>
<ul>
<li>
<a href="s_98.html#s03_02_02_03_01">3.2.2.3.1 The #fopen Directive</a>
<li>
<a href="s_98.html#s03_02_02_03_02">3.2.2.3.2 The #fclose Directive</a>
<li>
<a href="s_98.html#s03_02_02_03_03">3.2.2.3.3 The #read Directive</a>
<li>
<a href="s_98.html#s03_02_02_03_04">3.2.2.3.4 The #write Directive</a>
</ul>
<li>
<a href="s_98.html#s03_02_02_04">3.2.2.4 The #default Directive</a>
<li>
<a href="s_98.html#s03_02_02_05">3.2.2.5 The #version Directive</a>
<li>
<a href="s_98.html#s03_02_02_06">3.2.2.6 Conditional Directives</a>
<ul>
<li>
<a href="s_98.html#s03_02_02_06_01">3.2.2.6.1 The #if...#else...#end Directives</a>
<li>
<a href="s_98.html#s03_02_02_06_02">3.2.2.6.2 The #ifdef and #ifndef Directives</a>
<li>
<a href="s_98.html#s03_02_02_06_03">3.2.2.6.3 The #switch, #case, #range and #break Directives</a>
<li>
<a href="s_98.html#s03_02_02_06_04">3.2.2.6.4 The #while...#end Directive</a>
</ul>
<li>
<a href="s_98.html#s03_02_02_07">3.2.2.7 User Message Directives</a>
<ul>
<li>
<a href="s_98.html#s03_02_02_07_01">3.2.2.7.1 Text Message Streams</a>
<li>
<a href="s_98.html#s03_02_02_07_02">3.2.2.7.2 Text Formatting</a>
</ul>
<li>
<a href="s_98.html#s03_02_02_08">3.2.2.8 User Defined Macros</a>
<ul>
<li>
<a href="s_98.html#s03_02_02_08_01">3.2.2.8.1 The #macro Directive</a>
<li>
<a href="s_98.html#s03_02_02_08_02">3.2.2.8.2 Invoking Macros</a>
<li>
<a href="s_98.html#s03_02_02_08_03">3.2.2.8.3 Are POV-Ray Macros a Function or a Macro?</a>
<li>
<a href="s_98.html#s03_02_02_08_04">3.2.2.8.4 Returning a Value Like a Function</a>
<li>
<a href="s_98.html#s03_02_02_08_05">3.2.2.8.5 Returning Values Via Parameters</a>
</ul>
</ul>
</ul>
<p>
<a name="l52">
<small><strong>More about "Notation and Basic Assumptions"</strong></small>
</a>
<ul>
<li><small>
<a href="s_55.html#s02_01_07">2.1.7 Notation and Basic Assumptions</a> in 2.1 Introduction
</small>
<li><small>
<a href="s_94.html#s03_01_01">3.1.1 Notation and Basic Assumptions</a> in 3.1 Introduction
</small>
</ul>
</p>
<p>
<a name="l53">
<small><strong>More about "Language Directives"</strong></small>
</a>
<ul>
<li><small>
<a href="s_156.html#s03_08_04">3.8.4 Language Directives</a> in 3.8 Quick Reference
</small>
<li><small>
<a href="s_98.html#s03_02_02">3.2.2 Language Directives</a> in 3.2 Scene Description Language
</small>
</ul>
</p>
<p>
<a name="l54">
<small><strong>More about "Object"</strong></small>
</a>
<ul>
<li><small>
<a href="s_104.html#s03_04">3.4 Objects</a> in 3 POV-Ray Reference
</small>
<li><small>
<a href="s_125.html#s03_05_11_23">3.5.11.23 Object Pattern</a> in 3.5.11 Patterns
</small>
<li><small>
<a href="s_160.html#s03_08_08">3.8.8 Objects</a> in 3.8 Quick Reference
</small>
</ul>
</p>
<p>
<a name="l55">
<small><strong>More about "Camera"</strong></small>
</a>
<ul>
<li><small>
<a href="s_100.html#s03_03_01">3.3.1 Camera</a> in 3.3 Scene Settings
</small>
<li><small>
<a href="s_158.html#s03_08_06">3.8.6 Camera</a> in 3.8 Quick Reference
</small>
</ul>
</p>
<p>
<a name="l56">
<small><strong>More about "Atmospheric Effects"</strong></small>
</a>
<ul>
<li><small>
<a href="s_101.html#s03_03_02">3.3.2 Atmospheric Effects</a> in 3.3 Scene Settings
</small>
<li><small>
<a href="s_164.html#s03_08_12">3.8.12 Atmospheric Effects</a> in 3.8 Quick Reference
</small>
</ul>
</p>
<p>
<a name="l57">
<small><strong>More about "Global Settings"</strong></small>
</a>
<ul>
<li><small>
<a href="s_102.html#s03_03_03">3.3.3 Global Settings</a> in 3.3 Scene Settings
</small>
<li><small>
<a href="s_165.html#s03_08_13">3.8.13 Global Settings</a> in 3.8 Quick Reference
</small>
<li><small>
<a href="s_75.html#s02_03_10_04">2.3.10.4 Global settings</a> in 2.3.10 SDL tutorial: A raytracer
</small>
</ul>
</p>
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