3.8.2 The Scene

POV-Ray 3.6 for UNIX documentation 3.8.3 Language Basics

3.8.4 Language Directives

3.8.3 Language Basics

3.8.3.1 Floats

Float Expressions

FLOAT:

NUMERIC_TERM [SIGN NUMERIC_TERM]...

SIGN:

+ | -

NUMERIC_TERM:

NUMERIC_FACTOR [MULT NUMERIC_FACTOR]...

MULT:

* | /

NUMERIC_EXPRESSION:

FLOAT_LITERAL | FLOAT_IDENTIFIER | SIGN NUMERIC_EXPRESSION | FLOAT_FUNCTION | FLOAT_BUILT_IN_IDENT | ( FULL_EXPRESSION ) | ! NUMERIC_EXPRESSION | VECTOR.DOT_ITEM | FLOAT_FUNCTION_INVOCATION

FLOAT_LITERAL:

[DIGIT...][.]DIGIT...[EXP[SIGN]DIGIT...]

DIGIT:

0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9

EXP:

e | E

FLOAT_FUNCTION:

abs (FLOAT) | acos (FLOAT) | acosh (FLOAT) | asc (STRING) | asin (FLOAT) | asinh (FLOAT) | atan (FLOAT) | atanh (FLOAT) | atan2 (FLOAT,FLOAT) | ceil (FLOAT) | cos (FLOAT) | cosh (FLOAT) | defined (IDENTIFIER) | degrees (FLOAT) | dimensions (ARRAY_IDENTIFIER) | dimension_size (ARRAY_IDENTIFIER,INT) | div (FLOAT,FLOAT) | exp (FLOAT) | file_exists (STRING) | floor (FLOAT) | int (FLOAT) | inside (SOLID_OBJECT_IDENT, VECTOR) | ln (FLOAT) | log (FLOAT) | max (FLOAT,FLOAT[,FLOAT]...) | min (FLOAT,FLOAT[,FLOAT]...) | mod (FLOAT,FLOAT) | pow (FLOAT,FLOAT) | radians (FLOAT) | rand (FLOAT) | seed (FLOAT) | select (FLOAT,FLOAT,FLOAT,[FLOAT]) | sin (FLOAT) | sinh (FLOAT) | sqrt (FLOAT) | strcmp (STRING,STRING) | strlen (STRING) | tan (FLOAT) | tanh (FLOAT) | val (STRING) | vdot (VECTOR,VECTOR) | vlength (VECTOR)

FLOAT_BUILT_IN_IDENT:

BOOLEAN_KEYWORD | clock | clock_delta | clock_on | final_clock | final_frame | frame_number | image_height | image_width | initial_clock | initial_frame | pi | version

BOOLEAN_KEYWORD:

true | yes | on | false | no | off

FULL_EXPRESSION:

LOGICAL_EXPRESSION [? FULL_EXPRESSION : FULL_EXPRESSION]

LOGICAL_EXPRESSION:

REL_TERM [LOGICAL_OPERATOR REL_TERM]...

LOGICAL_OPERATOR:

& | |

REL_TERM:

FLOAT [REL_OPERATOR FLOAT]...

REL_OPERATOR:

< | <= | = | >= | > | !=

DOT_ITEM:

x | y | z | t | u | v | red | green | blue | filter | transmit | gray

INT:

FLOAT

Any fractional part is discarded.

BOOL:

BOOLEAN_KEYWORD | LOGICAL_EXPRESSION

 

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3.8.3.2 Vectors

Vector Expressions

VECTOR:

VECTOR_TERM [SIGN VECTOR_TERM]...

VECTOR_TERM:

VECTOR_EXPRESSION [MULT VECTOR_EXPRESSION]...

VECTOR_EXPRESSION:

VECTOR_LITERAL | VECTOR_IDENTIFIER | SIGN VECTOR_EXPRESSION | VECTOR_FUNCTION | VECTOR_BUILT_IN_IDENT | ! VECTOR_EXPRESSION | FLOAT | VECTOR_FUNCTION_INVOCATION | COLOR_FUNCTION_INVOCATION | SPLINE_INVOCATION

VECTOR_LITERAL:

< FLOAT, FLOAT [, FLOAT [, FLOAT [, FLOAT ]]] >

VECTOR_FUNCTION:

min_extent (OBJECT_IDENTIFIER) | max_extent (OBJECT_IDENTIFIER) | trace (OBJECT_IDENTIFIER,VECTOR,VECTOR[,VECTOR_IDENTIFIER]) | vaxis_rotate (VECTOR,VECTOR,FLOAT) | vcross (VECTOR,VECTOR) | vrotate (VECTOR,VECTOR) | vnormalize (VECTOR) | vturbulence (FLOAT,FLOAT,FLOAT,VECTOR)

VECTOR_BUILT_IN_IDENT:

x | y | z | t | u | v

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3.8.3.3 Colors

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3.8.3.4 User defined Functions

User-Defined Functions

USER_FUNCTION:

FLOAT_USER_FUNCTION | VECTOR_USER_FUNCTION | COLOR_USER_FUNCTION

FLOAT_USER_FUNCTION:

function { FN_FLOAT } | function (IDENT_LIST) { FN_FLOAT } | function { pattern { PATTERN [PATTERN_MODIFIERS]} }

IDENT_LIST:

IDENT_ITEM [, IDENT_LIST]

The maximum number of parameter identifiers is 56. An identifier may not be repeated in the list.

IDENT_ITEM:

x | y | z | u | v | PARAM_IDENTIFIER

PATTERN:

MAP_PATTERN | brick [BRICK_ITEM] | checker | hexagon | object { LIST_OBJECT }

VECTOR_USER_FUNCTION:

function { SPECIAL_VECTOR_FUNCTION }

SPECIAL_VECTOR_FUNCTION:

TRANSFORM | SPLINE

COLOR_USER_FUNCTION:

function { PIGMENT }

Specify a float expression in a user-defined function:

FN_FLOAT

LOGIC_AND [OR LOGIC_AND]

OR:

|

LOGIC_AND:

REL_TERM [AND REL_TERM]

AND:

&

REL_TERM:

TERM [REL_OPERATOR TERM]

REL_OPERATOR:

< | <= | = | >= | > | !=

TERM:

FACTOR [SIGN FACTOR]

SIGN:

+ | -

FACTOR:

EXPRESSION [MULT EXPRESSION]

MULT:

* | /

EXPRESSION:

FLOAT_LITERAL | FLOAT_IDENTIFIER | FN_FLOAT_FUNCTION | FLOAT_BUILT_IN_IDENT | ( FN_FLOAT ) | IDENT_ITEM | SIGN EXPRESSION | VECTOR_FUNCTION_INVOCATION.FN_DOT_ITEM | COLOR_FUNCTION_INVOCATION.FN_DOT_ITEM | FLOAT_FUNCTION_INVOCATION

FN_DOT_ITEM:

DOT_ITEM | hf

FN_FLOAT_FUNCTION:

abs (FN_FLOAT) | acos (FN_FLOAT) | acosh (FN_FLOAT) | asin (FN_FLOAT) | asinh (FN_FLOAT) | atan (FN_FLOAT) | atanh (FN_FLOAT) | atan2 (FN_FLOAT,FN_FLOAT) | ceil (FN_FLOAT) | cos (FN_FLOAT) | cosh (FN_FLOAT) | degrees (FN_FLOAT) | exp (FN_FLOAT) | floor (FN_FLOAT) | int (FN_FLOAT) | ln (FN_FLOAT) | log (FN_FLOAT) | max (FN_FLOAT,FN_FLOAT[,FN_FLOAT]...) | min (FN_FLOAT,FN_FLOAT[,FN_FLOAT]...) | mod (FN_FLOAT,FN_FLOAT) | pow (FN_FLOAT,FN_FLOAT) | prod (IDENTIFIER, FN_FLOAT, FN_FLOAT, FN_FLOAT) | radians (FN_FLOAT) | sin (FN_FLOAT) | sinh (FN_FLOAT) | sqrt (FN_FLOAT) | sum (IDENTIFIER, FN_FLOAT, FN_FLOAT, FN_FLOAT) |tan (FN_FLOAT) | tanh (FN_FLOAT) | select (FN_FLOAT,FN_FLOAT,FN_FLOAT [,FN_FLOAT])

Create an identifier for a user-defined function:

USER_FUNCTION_DECLARATION:

#declare FLOAT_FUNCTION_IDENTIFIER = FLOAT_USER_FUNCTION |
#local FLOAT_FUNCTION_IDENTIFIER = FLOAT_USER_FUNCTION |
#declare VECTOR_FUNCTION_IDENTIFIER = VECTOR_USER_FUNCTION |
#local VECTOR_FUNCTION_IDENTIFIER = VECTOR_USER_FUNCTION |
#declare COLOR_FUNCTION_IDENTIFIER = COLOR_USER_FUNCTION |
#local COLOR_FUNCTION_IDENTIFIER = COLOR_USER_FUNCTION

Reference a user-defined function:

FLOAT_FUNCTION_INVOCATION:

FLOAT_FUNCTION_IDENTIFIER (FN_PARAM_LIST)

VECTOR_FUNCTION_INVOCATION:

VECTOR_FUNCTION_IDENTIFIER (FN_PARAM_LIST)

COLOR_FUNCTION_INVOCATION:

COLOR_FUNCTION_IDENTIFIER (FN_PARAM_LIST)

FN_PARAM_LIST:

FN_PARAM_ITEM [, FN_PARAM_LIST]

FN_PARAM_ITEM:

x | y | z | u | v | FLOAT

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3.8.3.5 Strings

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3.8.3.6 Arrays

Place a value into an array:

ARRAY_ELEMENT_ASSIGNMENT:

#declare ARRAY_REFERENCE =RVALUE [;] |
#local ARRAY_REFERENCE = RVALUE [;]

The semicolon is required for a FLOAT, VECTOR or COLOR assignment.

Reference an array:

ARRAY_REFERENCE:

ARRAY_IDENTIFIER ELEMENT...

ELEMENT:

[ INT ]

The brackets here are part of the element specification.

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3.8.3.7 Splines

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3.8.2 The Scene

3.8.3 Language Basics

3.8.4 Language Directives