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- POV-Ray Tutorial
- Conditional
Statements
Branching
#if(...) ... #else ... #end
- in loops
- in macros
- in animations
- turning on/off of parts
#switch(...) #case(..) ...
#range(..) ... #end
- selection by tables
Check for Existence
> #ifdef(...) #ifndef(...)
- Check in include files
- Defaults in include files
Loops
Prechecked, Postchecked,
Count-controlled, Early-Exit
#while(...)... #end
#for(...)... #end
- Samples:
- Loops with POV-Ray
- Loops, Sine, Cosine
- Random with POV-Ray
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Branching by Check for Existance
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In the scenery description language (SDL) of POV-Ray there are structures,
which allow us to realizise conditional statements depending on weather a variable is declared or not:
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Syntax in POV-Ray:
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#ifdef (Variable)
... statement
#else // (optional)
... statement2
#end |
Checks if a variable is declared.
This declaration can be done
global by "#declare" as well as also
local by "#local" .
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#ifndef (Variable)
... statement
#else // (optional)
... statement2
#end |
Checks if a variable is not declared
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#undef (Variable)
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Destroys a former declared variable.
If there exist multiple local declared vrsions of a variable, the
most recent and most local one will be destroyed (deleted), all variables with the same name at higher
levels (declared by "#declare" or "#local") will still exist.
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