On 2013-12-16 02:03, clipka wrote:
> Note that it is not your s itself that matters, but the size of the
> resulting structures. You're at 3e-5 there (for s=1), which is obviously
> still close enough to 1e-6 to give you problems.
>
> Also note how your scene is unconventionally small anyway, with the
> primary scene content having a size in the order of 0.1 units (again at
> s=1).
>
> I'm sorry to say this, but POV-Ray wasn't designed with this scenario in
> mind. Traditionally, scenes are designed with the primary content having
> a size in the order of 1 unit or above.

Thank you for your explanations. So, in order for POV-Ray to work 
properly, the distance between any two geometrical features (such as the 
inner and outer surface of a thin shell) must be well above 1e-6 POV-Ray 
units? This raises a few questions.

1. Is this documented somewhere? I cannot be the only one who is 
affected by this. Again, IMHO, this is a major deficiency in POV-Ray 
that people should know about, or they will get unexpected/wrong 
behavior. For instance, they can't use SI units for a scene involving 
micrometer-scale objects.

2. What about fractals? They certainly range to much smaller scales 
easily, even if the global size is, say, in the order of 1 unit.

3. Could you please, if you can, point me to the location in the source 
code where this constant is set/used?. I'd like to experiment with this 
a bit.

-Roman

Post a reply to this message