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#### Float Identifiers

Float identifiers may be declared to make scene files more readable and to parameterize scenes so that changing a single declaration changes many values. An identifier is declared as follows.

FLOAT_DECLARATION:
`
  #declare
`IDENTIFIER `=` EXPRESSION`;` | `
  #local
`IDENTIFIER `=` EXPRESSION`;`

Where IDENTIFIER is the name of the identifier up to 40 characters long and EXPRESSION is any valid expression which evaluates to a float value. Note that there should be a semi-colon after the expression in a float declaration. This semi-colon is new with POV-Ray version 3.1. If omitted, it generates a warning and some macros may not work properly. See "#declare vs. #local" for information on identifier scope. Here are some examples.

     #declare Count = 0;

     #declare Rows = 5.3;

     #declare Cols = 6.15;

     #declare Number = Rows*Cols;

     #declare Count = Count+1;

As the last example shows, you can re-declare a float identifier and may use previously declared values in that re-declaration. There are several built-in identifiers which POV-Ray declares for you. See "Built-in Float Identifiers" for details.

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