clipka <ano### [at] anonymousorg> wrote:

>
> There's a twofold problem here:
>
[snip
> - Whatever the details of such countermeasure would be, it would
> inevitably involve looking at the true geometric surface normal.
> Unfortunately, POV-Ray currently only passes around the fake-smoothed
> surface normal and the perturbed surface normal.
>

*Thanks* for taking the time to explain this. It *is* a complex subject.

I need a little clarifaction, just to improve for my own understanding:

I take the "true geometric surface normal" to mean the unalterted,
un-interpolated *single* normal on the face of the flat triangle. Is that
correct?

Also: It is becoming clearer to me as to why SSLT works better on an object with
finer-and-finer triangle subdivisions (and perhaps not so well with large flat
'mathematical' slabs like a box object?) The smaller triangles-- curving away at
slightly different angles-- cause the (many) incoming rays (and subsequent
subsurface 'volume gathering') to be averaged together in a smoother way, with
the artifacts contributing less to the 'larger' average, or being swamped by it.
This is my layman's understanding, anyway ;-)  Please correct me if I'm mistaken
or hopelessly wrong. If I'm at least somewhat correct, then POV-Ray's in-built
documentation doesn't actually mention the need for finer triangle-mesh
subdivisions, to get a smoother look. Perhaps it should, in light of Flyer X's
results.

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