stevenvh napsal(a):
> In the past I always "differenced" objects, never a plane, and maybe that's why
> I never noticed this before. Say I want a sphere with the top cut off:
> 
> difference {
>     sphere { 0 1  }
>     plane { y 0.8 }
>     texture { T_Brass_1D }
> }
> 
> Not what I want; only the top segment is kept. Logic holds that
> 
>     plane { -y -0.8 }
> 
> should do the trick, cutting away the stuff above the (inversed) plane instead
> of below it. But POV-Ray doesn't seem to accept negative distances here!
> How do I do this?
> TIA
> 
> 
It does support negative distances here. What happens here is that it 
understands -y-0.8 as a single expression. You should type 
plane{-y,-0.8} instead.
-- 
You know you've been raytracing too long when...
you ever saw a beautiful scenery and regretted not to take your 6" 
reflective ball and a digital camera, thinking "this would have been a 
perfect light probe"
-Johnny D

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