In article <3c5b3764$1@news.povray.org> , "JRG" <jrg### [at] hotmailcom> wrote:

> I've just noticed that the behaviour of the two operators | and & has changed
> again (at least in functions). With MegaPov I could make unions between
> isosurfaces with the operator |. With the last beta, I managed to accomplish
> the same result with &. In beta 10 neither work. I have to use min (f1,f2).

Yes, "and"/"or" work the same way as everywhere else in POV-Ray now.  Before
they were nothing more than synonyms for "min"/"max".  This had been mentioned
in this group several times.  However, I am not sure if the docs are updated
in beta 10 or not.

> Ok, just in case this is a known bug/feature, I have a bonus question: why do
> I need to translate the iso by a little amount in order to avoid a
> "floating-point exception" fatal error? Why if I translate it along the x
> instead of z (or y) the trick doesn't work? Shouldn't the iso remain the same
> since I'm not translating it at a 'function level'?

Because you divide something by "y".  If "y" happens to be zero, you get the
error because, as you know, the division by zero is not defined.  Depending on
what you want to do, you have to use "select" and assign an appropriate value
to divide by if "y" is zero.  The value to use depends on your function,
starting with a very small number might be a good idea.  If it doesn't give
you good results, in some functions using one works as well.

    Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

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