POV-Ray

https://www.povray.org/documentation/3.7.0/
Admin
POV-Ray is a powerful, open-source ray tracer that creates high-quality 3D graphics, used for...
Tokens:188,374
Snippets:2,265
Trust Score:9.6
Update:3 months ago
Show doc for...
Tokens:
Raw
### Complete povray.conf Example

Source: https://www.povray.org/documentation/3.7.0/u1_4.html

A comprehensive example showing File I/O security, shellout security, and various permitted path configurations.

```ini
[File I/O Security]
; none
; read-only
restricted

[Shellout Security]
allowed
; forbidden

[Permitted Paths]
read*=%INSTALLDIR%/include
read*=%INSTALLDIR%/scenes
read=%INSTALLDIR%/../../etc
read+write=.
read+write*=/tmp
```

--------------------------------

### Image Map Usage Examples

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Examples showing explicit file type declaration versus implicit type detection based on output settings.

```POV-Ray
plane { -z,0 
  pigment {
    image_map {png "Eggs.png"}
    }
  }

plane { -z,0 
  pigment {
    image_map {"Eggs"}
    }
  }
```

--------------------------------

### Initialize Scene Environment

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Standard scene setup including camera, background, and lighting.

```POV-Ray
  #include "colors.inc"
  camera {
    location <10, 5, -20>
    look_at 0
    angle 15
  }
  background { color rgb <.5, .5, .5> }
  light_source { <10, 50, -100> White }
```

```POV-Ray
  #include "colors.inc"
  #include "textures.inc"
  camera {
    location <10, 5, -20>
    look_at 0
    angle 15
  }
  background { color rgb <.5, .5, .5> }
  light_source{ <10, 50, -100> White }
```

--------------------------------

### Read Directive Example

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of a #read directive expecting specific data formats.

```POV-Ray
#read (FILE_HANDLE_IDENTIFIER,MyString,MyFloat,MyVect)
```

--------------------------------

### Implement a while loop

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of a standard #while loop used to place multiple objects.

```POV-Ray
#declare Count=0;
#while (Count < 5)
  object { MyObject translate x*3*Count }
  #declare Count=Count+1;
#end
```

--------------------------------

### Configure Object Photon Settings

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of enabling reflection and refraction for a specific object.

```POV-Ray
object {
  MyObject
  photons {
    target
    refraction on
    reflection on
    collect off
    }
  }
```

--------------------------------

### Configure Light Source Photon Settings

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of enabling reflection and refraction for a light source.

```POV-Ray
light_source {
  MyLight
  photons {
    refraction on
    reflection on
    }
  }
```

--------------------------------

### Set Read-Only Installation Directory

Source: https://www.povray.org/documentation/3.7.0/u1_4.html

Permit reading from the directory where POV-Ray supplementary files are installed.

```ini
[Permitted Paths]
read=%INSTALLDIR%
```

--------------------------------

### Macro Example: Window Frame

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

A practical example of a macro that creates a window frame object based on provided dimensions.

```POV-Ray
#macro Make_Frame(OuterWidth,OuterHeight,InnerWidth,
        InnerHeight,Depth)
#local Horz = (OuterHeight-InnerHeight)/2;
#local Vert = (OuterWidth-InnerWidth)/2;
difference {
  box {
    <0,0,0>,<OuterWidth,OuterHeight,Depth>
    }
  box {
    <Vert,Horz,-0.1>,
    <OuterWidth-Vert,OuterHeight-Horz,Depth+0.1>
    }
  }
#end
Make_Frame(8,10,7,9,1) //invoke the macro
```

--------------------------------

### Basic Identifier Examples

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Examples of declaring various data types and using them within object definitions.

```POV-Ray
#declare Rows = 5;
#declare Count = Count+1;
#local  Here = <1,2,3>;
#declare White = rgb <1,1,1>;
#declare Cyan = color blue 1.0 green 1.0;
#declare Font_Name = "ariel.ttf"
#declare Rod = cylinder {-5*x,5*x,1}
#declare Ring = torus {5,1}
#local  Checks = pigment { checker White, Cyan }

object { Rod scale y*5 } // not "cylinder { Rod }"
object {
  Ring
  pigment { Checks scale 0.5 }
  transform Skew
  }
```

--------------------------------

### Example Color Declarations

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Examples showing various ways to define color identifiers, including using expressions and existing identifiers.

```POV-Ray
#declare White = rgb <1,1,1>;
#declare Cyan = color blue 1.0 green 1.0;
#declare Weird = rgb <Foo*2,Bar-1,Bob/3>;
#declare LightGray = White*0.8;
#declare LightCyan = Cyan red 0.6;
```

--------------------------------

### Write Directive Implementation

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example code demonstrating how to write data to a file using the #write directive.

```POV-Ray
#declare Val1 = -123.45;
#declare Vect1 = <1,2,-3>;
#write (FILE_HANDLE_IDENTIFIER,"\"A quote delimited string\",",Val1,",",Vect1,"\n")
```

--------------------------------

### Configure Photons in Global Settings

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of adding a photons block to the global_settings section of a scene.

```POV-Ray
global_settings {
  photons {
    count 20000
    autostop 0
    jitter .4
    }
  }
```

--------------------------------

### Configure Global Media Photon Settings

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of enabling photon interaction with media in global settings.

```POV-Ray
global_settings {
  photons {
    count 10000
    media 100
    }
  }
```

--------------------------------

### Complete While Loop Structure

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

A full example of a while loop including initialization, condition, body, and manual incrementing.

```POV-Ray
#declare Index = 1;
#while(Index <= 10)

  (some commands here)

  #declare Index = Index + 1;
#end
```

--------------------------------

### Retrieving Date and Time

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Syntax for the datetime function and an example using the now keyword.

```POV-Ray
datetime(FLOAT [,STRING])
```

```POV-Ray
datetime(now)
```

--------------------------------

### Initialize Multi-Dimensional Array

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of initializing a multi-dimensional array using nested initializer syntax.

```POV-Ray
#declare Digits =
array[4][10] {
  {7,6,7,0,2,1,6,5,5,0},
  {1,2,3,4,5,6,7,8,9,0},
  {0,9,8,7,6,5,4,3,2,1},
  {1,1,2,2,3,3,4,4,5,5}
  }
```

--------------------------------

### Example of conditional #if usage

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Demonstrates using #if, #elseif, and #else to control output based on float expressions.

```POV-Ray
#if (Foo)
  #debug "Foo is true\n"
#elseif (Bar)
  #debug "Foo is false, but Bar is true\n"
#else
  #debug "Foo and Bar are both false\n"
#end
```

--------------------------------

### Transformation Order Example

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Demonstrates the effect of scaling after translation, which multiplies the translation amount.

```POV-Ray
  translate <5, 6, 7>
  scale 4
```

--------------------------------

### Initialize One-Dimensional Array

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of initializing a one-dimensional array using array initializer syntax.

```POV-Ray
#include "colors.inc"
#declare FlagColors = array[3] {Red,White,Blue}
```

--------------------------------

### Nested Loop Initialization Example

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Initializes nested loops for creating a 2D array of objects.

```POV-Ray SDL
#declare Index1 = 0;
#while(Index1 <= 9)

   #declare Index2 = 0;
   #while(Index2 <= 19)
```

--------------------------------

### Create a Simple Polygon Object

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Example of a single polygon object representing the letter V, including camera and light source setup.

```POV-Ray
  camera {
    orthographic
    location <0, 0, -10>
    right 1.3 * 4/3 * x
    up 1.3 * y
    look_at <0, 0.5, 0>
  }
  light_source { <25, 25, -100> color rgb 1 }
  polygon {
    8,
    <0.45, 0.0>, <0.30, 1.0>, // Letter "V"
    <0.40, 1.0>, <0.55, 0.1>,
    <0.70, 1.0>, <0.80, 1.0>,
    <0.65, 0.0>,
    <0.45, 0.0>
    pigment { color rgb <1, 0, 0> }
  }
```

--------------------------------

### Intersection Example

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

An example of an intersection between a box and a cylinder.

```POV-Ray
intersection {
  box { <-1.5, -1, -1>, <0.5, 1, 1> }
  cylinder { <0.5, 0, -1>, <0.5, 0, 1>, 1 }
  }
```

--------------------------------

### Apply Density with Color List

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of using a checker pattern with a density color list.

```POV-Ray SDL
density {
 checker 
   density {rgb<1,0,0>}
   density {rgb<0,0,0>}
   }
```

--------------------------------

### Multi-line comment example

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Demonstrates the use of block comments to ignore multiple lines of code.

```POV-Ray
/* These lines
are ignored
by the
ray-tracer */
```

--------------------------------

### Vector Identifier Examples

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Examples showing the declaration and re-declaration of vector identifiers.

```POV-Ray
#declare Here = <1,2,3>;
#declare There = <3,4,5>;
#declare Jump = <Foo*2,Bar-1,Bob/3>;
#declare Route = There-Here;
#declare Jump = Jump+<1,2,3>;
```

--------------------------------

### Sample INI File Structure

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Demonstrates basic INI file syntax including comments, input file settings, and nested INI file inclusion.

```ini
  ; This is a sample INI file. This entire line is a comment.
  ; Blank lines are permitted.
  Input_File_Name=simple.pov ;This sets the input file name
  +W80 +H60 ; Traditional +/- switches are permitted too
  MOREOPT   ; Read MOREOPT.INI and continue with next line
  +V        ; Another switch
  ; That's all folks!
```

--------------------------------

### Render Preview with Gamma Settings

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Use these command-line parameters to render the showcase scene in a preview window for sanity checking.

```text
  +w640 +h480 +a0.3 +am1 -f +d
```

--------------------------------

### Example of an Averaged Pigment

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

A practical example of averaging three pigments with specific weights.

```povray
pigment {
  average
  pigment_map {
    [1.0  Pigment_1]
    [2.0  Pigment_2]
    [0.5  Pigment_3]
    }
  }
```

--------------------------------

### Execute POV-Ray with Command Line Switches

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Example of running the POV-Ray executable with specific switches to define input files, verbosity, and image dimensions.

```bash
  povray +Isimple.pov +V +W80 +H60
```

--------------------------------

### Object Pattern Example

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of using the object pattern with a declared object and turbulence.

```POV-Ray
pigment {
  object {
    myTextObject 
    color White 
    color Red
    }
  turbulence 0.15
  }
```

--------------------------------

### Complete POV-Ray Scene Example

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

A full scene file including background, camera, sphere, and light source.

```POV-Ray
  #include "colors.inc"
  background { color Cyan }
  camera {
    location <0, 2, -3>
    look_at  <0, 1,  2>
  }
  sphere {
    <0, 1, 2>, 2
    texture {
      pigment { color Yellow }
    }
  }
  light_source { <2, 4, -3> color White}
```

--------------------------------

### Square Polygon Example

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

A simple square polygon example using 2D vectors and a texture.

```POV-Ray
polygon {
  4,
  <0, 0>, <0, 1>, <1, 1>, <1, 0>
  texture {
    finish { ambient 1 diffuse 0 }
    pigment { image_map { gif "test.gif"  } }
    }
  //scale and rotate as needed here
  }
```

--------------------------------

### Example of a Text Object

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

A practical example of defining a text object with a specific font and pigment.

```POV-Ray
text {
  ttf "timrom.ttf" "POV-Ray" 1, 0
  pigment { Red }
  }
```

--------------------------------

### Initialize CSG Demo Scene

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Sets up the camera, lighting, and ground plane for a CSG demonstration.

```POV-Ray
  #include "colors.inc"
  camera {
    location <0, 1, -10>
    look_at 0
    angle 36
  }
  light_source { <500, 500, -1000> White }
  plane { y, -1.5
    pigment { checker Green White }
  }
```

--------------------------------

### Example of a Parametric Unit Sphere

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

A practical example of a parametric object representing a unit sphere.

```POV-Ray
parametric {
  function { sin(u)*cos(v) }
  function { sin(u)*sin(v) }
  function { cos(u) }

  <0,0>, <2*pi,pi>
  contained_by { sphere{0, 1.1} }
  max_gradient ??
  accuracy 0.0001
  precompute 10 x,y,z
  pigment {rgb 1}
  }
```

--------------------------------

### Pigment Map Example

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of a sphere using a gradient pattern with a pigment_map to blend multiple textures.

```POV-Ray
sphere {
  <0,1,2>, 2
  pigment {
    gradient x       //this is the PATTERN_TYPE
    pigment_map {
      [0.3 wood scale 0.2]
      [0.3 Jade]     //this is a pigment identifier
      [0.6 Jade]
      [0.9 marble turbulence 1]
      }
    }
  }
```

--------------------------------

### Initialize Chain Scene Environment

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Sets up the camera, lighting, and base objects required for modeling a chain link.

```POV-Ray
  #include "colors.inc"
  camera {
    location <0, .1, -25>
    look_at 0
    angle 30
  }
  background { color Gray50 }
  light_source{ <300, 300, -1000> White }
  #declare Half_Torus = difference {
    torus {
      4,1
      sturm
      rotate x*-90  // so we can see it from the top
    }
    box { <-5, -5, -1>, <5, 0, 1> }
    pigment { Green }
  }
  #declare Flip_It_Over = x*180;
  #declare Torus_Translate = 8;
```

--------------------------------

### Rainbow Arc Example

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

A practical example of a 120-degree rainbow arc with a 30-degree falloff region.

```POV-Ray SDL
rainbow {
  direction <0, 0, 1>
  angle 42.5
  width 5
  distance 1000
  jitter 0.01
  color_map { Rainbow_Color_Map }
  up <0, 1, 0>
  arc_angle 120
  falloff_angle 30
  }
```

--------------------------------

### Initialize Text Object Scene

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Sets up the camera, lighting, and a checkered plane for rendering text objects.

```POV-Ray
  #include "colors.inc"
  camera {
    location <0, 1, -10>
    look_at 0
    angle 35
  }
  light_source { <500,500,-1000> White }
  plane {
    y,0
    pigment { checker Green White }
  }
```

--------------------------------

### Julia Fractal Pigment Example

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of applying a Julia fractal pattern to a box object with custom interior coloring.

```POV-Ray
box {<-2, -2, 0>, <2, 2, 0.1>
  pigment {
    julia <0.353, 0.288>, 30
    interior 1, 1
    color_map { 
      [0 rgb 0]
      [0.2 rgb x]
      [0.4 rgb x+y]
      [1 rgb 1]
      [1 rgb 0]
      }
    }
  }
```

--------------------------------

### Use Functions from functions.inc

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Demonstrates how to include the functions library and apply predefined functions within isosurface or pigment blocks.

```POV-Ray SDL
#include "functions.inc"
isosurface {
  function { f_torus_gumdrop(x,y,z, P0) }
  ...
  }

pigment {
  function { f_cross_ellipsoids(x,y,z, P0, P1, P2, P3) }
  COLOR_MAP ...
  }
```

--------------------------------

### Implement a switch directive

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example demonstrating the use of #switch, #case, #range, and #break to handle conditional logic.

```POV-Ray
#switch (VALUE)
  #case (TEST_1)
    // This section is parsed if VALUE=TEST_1
  #break //First case ends
  #case (TEST_2)
    // This section is parsed if VALUE=TEST_2
  #break //Second case ends
  #range (LOW_1,HIGH_1)
    // This section is parsed if (VALUE>=LOW_1)&(VALUE<=HIGH_1)
  #break //Third case ends
  #range (LOW_2,HIGH_2)
    // This section is parsed if (VALUE>=LOW_2)&(VALUE<=HIGH_2)
  #break //Fourth case ends
  #else
    // This section is parsed if no other case or
    // range is true.
#end
```

--------------------------------

### Example Bicubic Patch Implementation

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

A concrete example of a bicubic_patch using 16 control points and specific subdivision settings.

```POV-Ray SDL
bicubic_patch {
  type 0
  flatness 0.01
  u_steps 4
  v_steps 4
  <0, 0, 2>, <1, 0, 0>, <2, 0, 0>, <3, 0,-2>,
  <0, 1  0>, <1, 1, 0>, <2, 1, 0>, <3, 1, 0>,
  <0, 2, 0>, <1, 2, 0>, <2, 2, 0>, <3, 2, 0>,
  <0, 3, 2>, <1, 3, 0>, <2, 3, 0>, <3, 3, -2>
  }
```

--------------------------------

### Define INI File Syntax and Equivalents

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Shows the standard format for INI file options and how to map command-line switches to INI keywords.

```ini
  Option_keyword=VALUE ; Text after semicolon is a comment
```

```ini
  Input_File_Name=simple.pov
```

--------------------------------

### Specify INI Files via Command Line

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Examples of passing INI configuration files as arguments to the POV-Ray command, either alone or combined with switches.

```bash
  povray myopts.ini
```

```bash
  povray myopts +V other
```

--------------------------------

### Example of a Gradient Texture Map

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

A practical example of using a gradient pattern to blend different textures based on float values.

```POV-Ray SDL
texture {
  gradient x           //this is the PATTERN_TYPE
  texture_map {
    [0.3  pigment{Red} finish{phong 1}]
    [0.3  T_Wood11]    //this is a texture identifier
    [0.6  T_Wood11]
    [0.9  pigment{DMFWood4} finish{Shiny}]
    }
  }
```

--------------------------------

### Implement Material Map with Multiple Textures

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example showing how to map multiple textures to specific indices of a PNG file.

```POV-Ray SDL
texture {
  material_map {
    png "povmap.png"
      texture {  //used with index 0
        pigment {color red 0.3 green 0.1 blue 1}
        normal  {ripples 0.85 frequency 10 }
        finish  {specular 0.75}
        scale 5
        }
      texture {  //used with index 1
        pigment {White}
        finish {
        ambient 0 diffuse 0 
        reflection 0.9 specular 0.75
        }
      }
      // used with index 2
      texture {pigment{NeonPink} finish{Luminous}}
      texture {  //used with index 3
        pigment {
          gradient y
          color_map {
            [0.00 rgb < 1 , 0 , 0>]
            [0.33 rgb < 0 , 0 , 1>]
            [0.66 rgb < 0 , 1 , 0>]
            [1.00 rgb < 1 , 0 , 0>]
            }
          }
        finish{specular 0.75}
        scale 8
        }
    }
  scale 30
  translate <-15, -15, 0>
  }
```

--------------------------------

### Cubic Spline Sphere Sweep Example

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

A cubic_spline sphere sweep example using six control points to create a curved object.

```POV-Ray
  sphere_sweep {
    cubic_spline
    6,
    <-4, -5, 0>, 1
    <-5, -5, 0>, 1
    <-5,  5, 0>, 0.5
    < 5, -5, 0>, 0.5
    < 5,  5, 0>, 1
    < 4,  5, 0>, 1
    tolerance 0.1
 }
```

--------------------------------

### Configuration File Syntax

Source: https://www.povray.org/documentation/3.7.0/u1_4.html

The general structure for POV-Ray configuration files, supporting comments and section-based settings.

```text
;Comment

[Section]
setting

```

--------------------------------

### Linear Sphere Sweep Example

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

A basic linear sphere sweep example forming an 'N' shape using four control points.

```POV-Ray
  sphere_sweep {
    linear_spline
    4,
    <-5, -5, 0>, 1
    <-5,  5, 0>, 1
    < 5, -5, 0>, 1
    < 5,  5, 0>, 1
  }
```

--------------------------------

### Union Example

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

A simple union containing a box and a cylinder.

```POV-Ray
union {
  box { <-1.5, -1, -1>, <0.5, 1, 1> }
  cylinder { <0.5, 0, -1>, <0.5, 0, 1>, 1 }
  }
```

--------------------------------

### Declare Multi-Dimensional Array

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of declaring a two-dimensional array.

```POV-Ray
#declare MyGrid = array[4][5]
```

--------------------------------

### Calculate Factorial using prod

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Demonstrates the use of the prod function to calculate a factorial, requiring a wrapper declaration.

```POV-Ray
#declare factorial = function(C) { prod(i, 1, C, i) }
#declare A = factorial(5);
```

--------------------------------

### Create a Basic Superellipsoid

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Example of a simple superellipsoid with a red pigment.

```POV-Ray
  superellipsoid { <.25, .25>
    pigment { Red }
  }
```

--------------------------------

### Include Standard POV-Ray Files

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Import pre-defined scene elements like colors and textures. Include only necessary files to optimize parsing time and memory usage.

```POV-Ray
  #include "colors.inc"    // The include files contain
  #include "stones.inc"    // pre-defined scene elements
```

```POV-Ray
  #include "textures.inc"    // pre-defined scene elements
  #include "shapes.inc"
  #include "glass.inc"
  #include "metals.inc"
  #include "woods.inc"
```

--------------------------------

### Define a Basic Spotlight

Source: https://www.povray.org/documentation/3.7.0/t2_2.html

Initial configuration for a spotlight source using the spotlight keyword and standard parameters.

```povray
  light_source {
    <0, 10, -3>
    color White
    spotlight
    radius 15
    falloff 20
    tightness 10
    point_at <0, 0, 0>
  }
```

--------------------------------

### Looping with the for directive

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of a loop that rotates a sphere at 30-degree increments.

```POV-Ray
#for (i,0,330,30)
  sphere { 0,1 translate <0,0,-10> rotate y*i }
#end
```

--------------------------------

### Demonstrate Macro Substitution Precedence

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Illustrates how macro substitution can lead to incorrect mathematical results if parentheses are omitted.

```POV-Ray SDL
#declare Value = Interpolate(I,0,15,3.0,5.5)*15;
```

```POV-Ray SDL
#declare Value = P1+(T1+T/(T2-T1))*(P2-P1) * 15;
```

```POV-Ray SDL
#declare Value = (P1+(T1+T/(T2-T1))*(P2-P1)) * 15;
```

--------------------------------

### Modify Default Pigment

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of changing only the default pigment component.

```POV-Ray
#default {
  pigment {rgb <1,0,0>}
  }
```

--------------------------------

### Declare One-Dimensional Array

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of declaring a simple one-dimensional array.

```POV-Ray
#declare MyArray = array[10]
```

--------------------------------

### Basic Macro Definition and Usage

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Demonstrates the basic syntax for defining and calling a macro in POV-Ray.

```POV-Ray
#macro UnitSphere()
  sphere { 0,1 }
#end

object { UnitSphere() pigment { rgb 1 } }
```

```POV-Ray
object { sphere { 0,1 } pigment { rgb 1 } }
```

--------------------------------

### Declare Index Identifier

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Initialize an index variable before starting a loop.

```POV-Ray
#declare Index = 1;
```

--------------------------------

### Initialize and use random number streams

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Demonstrates how to initialize multiple independent pseudo-random number streams using seed() and retrieve values with rand().

```POV-Ray SDL
#declare R1 = seed(0);
#declare R2 = seed(12345);
sphere { <rand(R1), rand(R1), rand(R1)>, rand(R2) }
```

--------------------------------

### Apply Turbulence to a Vector

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of using the vturbulence function to modify a vector.

```POV-Ray
#declare MyVector = MyVector + Amount * vturbulence(2, 0.5, 6, MyVector * Frequency);
```

--------------------------------

### Scaling Media Density in POV-Ray

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Demonstrates how to maintain consistent media appearance when scaling objects by adjusting the emission value.

```POV-Ray SDL
#version 3.5;
global_settings {
  assumed_gamma 1.0
  }

camera {location <0, 0,-12.0> look_at 0 angle 30 }

#declare Container_T =
  texture {
    pigment {rgbt <1,1,1,1>}
  finish {ambient 0 diffuse 0}
  }

#declare Scale=2;

box {                             //The reference
  <-1,-1,0>,<1,1,.3>
  hollow
  texture {Container_T}
  interior {
    media {
      intervals 1         
      samples 1,1          
      emission 1
      }
    }
  translate <-2.1,0,0>
  }

box {                             //Object scaled twice as big
  <-1,-1,0>,<1,1,.3>  //looks different but same
  hollow                          //particle density
  texture {Container_T}
    interior {
      media {
        intervals 1         
        samples 1,1          
        emission 1
        }
      }
  scale Scale
  translate<0,0,12>
  }

box {                             //Object scaled twice as big       
  <-1,-1,0>,<1,1,.3>  //looks the same but particle
  hollow                          //density scaled down
  texture {Container_T}
    interior {
      media {
        intervals 1         
        samples 1,1          
        emission 1/Scale
        }
      }
  scale Scale
  translate<0,0,12>
  translate<4.2,0,0>
  }
```

--------------------------------

### Nested multi-line comment example

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Demonstrates that multi-line comments can be nested within each other.

```POV-Ray
/* This is a comment
// This too
/* This also */
*/
```

--------------------------------

### Initialize Raytracer Parameters

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Calculates array dimensions and normalizes light source vectors using a while loop.

```POV-Ray SDL
#declare MaxDist = 1e5;
#declare ObjAmnt = dimension_size(Coord, 1);
#declare LightAmnt = dimension_size(LVect, 1);

#declare Ind = 0;
#while(Ind < LightAmnt)
  #declare LVect[Ind][0] = vnormalize(LVect[Ind][0]);
  #declare Ind = Ind+1;
#end
```

--------------------------------

### Solid Color Pigment

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of defining a pigment using a simple solid color.

```POV-Ray
pigment { color Orange }
```

--------------------------------

### Initialize a CSG Text Inlay Scene

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Initial setup for a scene using CSG, including includes, background, camera, and light source.

```pov
  #include "colors.inc"
  #include "stones.inc"
  background { color rgb 1 }
  camera {
    location <-3, 5, -15>
    look_at 0
    angle 25
  }
  light_source { <500,500,-1000> White }
```

--------------------------------

### Define Face Indices

Source: https://www.povray.org/documentation/3.7.0/r3_4.html

Example of the face_indices section structure within a mesh2 object.

```POV-Ray
face_indices {
  number_of_faces,
  <index_a, index_b, index_c>,
  <index_d, index_e, index_f>,
  ...
  }
```

--------------------------------

### Set Default Texture Properties

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Example of setting a full default texture including pigment, normal, and finish.

```POV-Ray
#default {
  texture {
    pigment { rgb <1,0,0> }
    normal { bumps 0.3 }
    finish { ambient 0.4 }
    }
  }
```

--------------------------------

### Valid Float Literals

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Examples of valid floating point literal representations in POV-Ray.

```text
 -2.0 -4 34 3.4e6 2e-5 .3 0.6
```

--------------------------------

### Using the select function

Source: https://www.povray.org/documentation/3.7.0/r3_3.html

Demonstrates the behavior of the select function with three and four parameters based on the value of A.

```povray
                         //    A =  -2 -1 0 1 2
select (A, -1, 0, 1)     //returns  -1 -1 0 1 1 
select (A, -1, 1)        //returns  -1 -1 1 1 1 
```

--------------------------------

### Define a Plain Texture for Layering

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

This snippet shows the initial setup of a base texture using a checker pattern, which can later be used as a foundation for layered textures.

```povray
  #include "colors.inc"
  camera {
    location <0, 0, -6>
    look_at <0, 0, 0>
  }
  light_source { <-20, 30, -100> color White }
  light_source { <10, 30, -10> color White }
  light_source { <0, 30, 10> color White }
  #declare PLAIN_TEXTURE =
    // red/white check
    texture {
      pigment {
        checker
        color rgb<1.000, 0.000, 0.000>
        color rgb<1.000, 1.000, 1.000>
        scale <0.2500, 0.2500, 0.2500>
      }
    }
  // plain red/white check box
  box {
    <-1, -1, -1>, <1, 1, 1>
    texture {
      PLAIN_TEXTURE
    }
    translate  <-1.5, 1.2, 0>
  }
```

--------------------------------

### Set Geometry Option

Source: https://www.povray.org/documentation/3.7.0/u1_6.html

Example of setting image dimensions and window position using the geometry flag.

```bash
-geometry 640x480+10+20
```

--------------------------------

### Initialize Mesh2 Object

Source: https://www.povray.org/documentation/3.7.0/t2_3.html

Start defining a mesh2 object using the vertex_vectors list.

```POV-Ray
mesh2 {
   vertex_vectors {
      24,
      ...
```
Tokens:
Raw