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Modelling Tips, Working With Primitives 
 POV-Ray Tips, 
 Tricks, and Techniques
Scaling an Object by (-1) to Create a Mirror Image? 
 
Robb S. Miller is worried: In attempting to model a building interior in POV-Ray, I felt lazy and wanted to model only half and mirror it to the other side, so I tried the following:

object { whatever scale -1*x }

I tested it on a cylinder and got an error message, but it did work.  Is there an easier/correct way to do this (like using a modeller) or what? 
 
Charles Fusner chuckles:
 Just a little TOO lazy, there, Robb <g>. You see, that shorthand
notation "x" is interpreted as being the vector <1,0,0>, so -1*x is the same as saying < -1, 0, 0>.  And of course, that isn't possible, since it would scale things by zero in the y and z directions. POV-Ray knows this, and will "correct" it for you by sticking ones in the zero places, but it issues the warning to remind you what you're trying to do is incorrect. To get rid of the message, just spell it out...

scale < -1, 1, 1>

and skip the whole business with "x". 
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