On:

cylinder {
<-1.835, 1.012, -0.3288>, <-1.835, 1.012, -0.3288>, 0.02201

I Get:
Parse Error: Degenerate cylinder, base point = apex point.

Can I tell povray to ignore such an invalid cylinder def?

Cheers,
Jurgen

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jfd wrote:
> On:
> 
> cylinder {
> <-1.835, 1.012, -0.3288>, <-1.835, 1.012, -0.3288>, 0.02201
> 
> I Get:
> Parse Error: Degenerate cylinder, base point = apex point.
> 
> Can I tell povray to ignore such an invalid cylinder def?
> 
> Cheers,
> Jurgen
> 
> 

Are you trying to make a disk (i.e. 2D cylinder)?  If so there is a disk 
object, I believe it is in "shapes.inc" (search the help file for 
"disk").  Otherwise, why not draw the disk as being a very, very thin 
cylinder:

cylinder {
<-1.835, 1.012, -0.3287>, <-1.835, 1.012, -0.3288>, 0.0220 }

Bryan

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> Can I tell povray to ignore such an invalid cylinder def?

I don't think so. If you're generating the cylinder automatically, you'll
probably have to use an #if to avoid creating it in the degenerate case. =(

 - Slime
 [ http://www.slimeland.com/ ]

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In article <42a0ccc8$1@news.povray.org>, "Slime" <fak### [at] emailaddress> 
wrote:

>>> Can I tell povray to ignore such an invalid cylinder def?
>>
>>I don't think so. If you're generating the cylinder automatically, you'll
>>probably have to use an #if to avoid creating it in the degenerate case. =(
>>
>> - Slime
>> [ http://www.slimeland.com/ ]

i agree slime but, if cylinder like this is generated automatically, i 
think there are some problems into the "generator" :)))

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kurtz le pirate nous apporta ses lumieres en ce 2005-06-04 06:17:
> In article <42a0ccc8$1@news.povray.org>, "Slime" <fak### [at] emailaddress> 
> wrote:
> 
> 
>>>>Can I tell povray to ignore such an invalid cylinder def?
>>>
>>>I don't think so. If you're generating the cylinder automatically, you'll
>>>probably have to use an #if to avoid creating it in the degenerate case. =(
>>>
>>>- Slime
>>>[ http://www.slimeland.com/ ]
> 
> 
> i agree slime but, if cylinder like this is generated automatically, i 
> think there are some problems into the "generator" :)))
In that case, POV Ray should issue a warning and continue, not stop with an error. If
you have a 
degenerate triangle, you get a warning and the parsing proceed. If you get a
degenerate bounding 
box, you get a warning and parsing proceed. That last one hapened to me while making a
macro.
The behaviour I expect: there is a degenerate <anything>, issue a warning, completely
ignore that 
element, proceed with the rest of the scene.

Alain

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> The behaviour I expect: there is a degenerate <anything>, issue a warning,
completely ignore that
> element, proceed with the rest of the scene.
>
> Alain

Thanks for your reactions guys. I agree with Alain that povray could simply
proceed after a warning. I can't change the generator (molmol).

Thanks,
Jurgen

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Alain <ele### [at] netscapenet> wrote:
> The behaviour I expect: there is a degenerate <anything>, issue a warning,
> completely ignore that element, proceed with the rest of the scene.

hmm, could we go as far as saying that there is a consistency issue? A
degenerate cylinder gives a parse error. I could imagine at least one good
reason for that: POV-Ray prevents the caps of the cylinder from being
co-incident surfaces. Now, a degenerate box (with one and only one
dimension set to 0) raises no error, no warning, and is rendered as a
rectangle with no thickness... Am i missing something?

JYR

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