"Hasan3" <PRO### [at] Yahoocom> wrote in message 
news:web.434968689b6ef72cc8a538750@news.povray.org...
> "Ken Hutson" <ken### [at] goettingcom> wrote:
>> The first three plane definitions pass through the parser. The fourth
>> generates an error. Why?
>>
>> plane{
>>  <0,0,1>,1
>>  pigment{rgb<1,1,1>}
>> }
>>
>> plane{
>>  <0,0,1>
>>  1
>>  pigment{rgb<1,1,1>}
>> }
>>
>> plane{
>>  <0,0,1>,-1
>>  pigment{rgb<1,1,1>}
>> }
>>
>> plane{
>>  <0,0,1>
>>  -1
>>  pigment{rgb<1,1,1>}
>> }
>>
>> Kenneth Hutson
>
>
>
> 4.plane :
> You have forgotten "," : it must like that:
>
> plane{
> <0,0,1>,
> -1
> pigment{rgb<1,1,1>}
> }
>
>
> Hasan...
>

Hasan is correct.
Just in case you're wondering why the second example works, it's because 
there's no positive or negative sign on the second parameter, so POV-Ray 
assumes it's the second parameter and is happy.
With your 4th example the minus sign is taken as a mathematical operation 
operating on the vector which evaluates to <-1,-1,0>. Then when POV-Ray 
looks for the second parameter it can't find it and complains.

Regards,
Chris B.

Post a reply to this message