"TC" <do-not-reply@i-do get-enough-spam-already-2498.com> wrote:
> But let us be glad that not every stone is a sparkling diamond...  it would
> become boring after a while.

True, and I'm glad I took the opportunity to try a translucent rock texture. But
Warp's right, this image isn't nearly as pretty as the first one. I think I'll
try a glass version to see how it looks...

> So: well done! I am looking forward for more :-)

Thank you, so am I! Although I'm undecided as to how to present the next lot.

Bill

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"Bill Pragnell" <bil### [at] hotmailcom> wrote:
> So, the next batch of polyhedra. This little lot are the Johnson solids,
> basically all the convex polyhedra composed only of regular polygons, that
> aren't either Platonic or Archimedean solids.

.... nor prisms or antiprisms. Otherwise we'd have an infinite lot of them :P

> There's 92 of them, so I thought
> the best way to show them off equally was another overhead view, in a spiral
> pattern this time. Rather than use the glass again, I thought I'd go for a
> polished stone look... mostly successful, I think.

Very beautifully arranged & illuminated (again!).

> (took 140 hours to render at 2000x2000 - eek!)

Sounds to me like a case of "ur doin' it wrong": I see nothing in that shot that
would justify such a long render time. Maybe too high-res area lighting? (Using
the "jitter" keyword is much superior to increasing maximum resolution.) Or
maybe too high-quality radiosity settings?

(Then again it's just a gut feeling, and maybe I'm missing something.)

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"clipka" <nomail@nomail> wrote:
> "Bill Pragnell" <bil### [at] hotmailcom> wrote:
> > (took 140 hours to render at 2000x2000 - eek!)
>
> Sounds to me like a case of "ur doin' it wrong": I see nothing in that shot that
> would justify such a long render time.

Yes, it's entirely possible. However, refining the render time would probably
take me several evenings' tinkering with the source, whereas if I just did
something else during that time it's half finished anyway. :) The isosurface
floor could probably use a smaller max_gradient, I could certainly get away
with a lower-res area_light, radiosity quality may well be too high, and I seem
to recall that the default media sampling (which this uses) is unwise. Including
the media seemed to produce the biggest slow-down... and, of course, merely
activating the aa on a scene like this is a huge drag.

(2000x2000 is also 4x the pixels posted here, but I guess you twigged that!)

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> "clipka" <nomail@nomail> wrote:
>> "Bill Pragnell" <bil### [at] hotmailcom> wrote:
>>> (took 140 hours to render at 2000x2000 - eek!)
>> Sounds to me like a case of "ur doin' it wrong": I see nothing in that shot that
>> would justify such a long render time.
> 
> Yes, it's entirely possible. However, refining the render time would probably
> take me several evenings' tinkering with the source, whereas if I just did
> something else during that time it's half finished anyway. :) The isosurface
> floor could probably use a smaller max_gradient, I could certainly get away
> with a lower-res area_light, radiosity quality may well be too high, and I seem
> to recall that the default media sampling (which this uses) is unwise. Including
> the media seemed to produce the biggest slow-down... and, of course, merely
> activating the aa on a scene like this is a huge drag.
> 
> (2000x2000 is also 4x the pixels posted here, but I guess you twigged that!)
> 
> 
Did you use adaptive for your area_light? It can greatly improve the 
rendering speed. With adaptive 1, a 65x65 area_light is barely slower 
than a 4x4 or 5x5 one without.

You may have inefecient bounding. If your construction make it that 
there are no bounding of your objects (intersection of planes), then 
each ray hace to be tested against every planes of every object. adding 
a bounded_by to your objects may greatly speed up the rendering.


Alain

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"Bill Pragnell" <bil### [at] hotmailcom> wrote:
> Yes, it's entirely possible. However, refining the render time would probably
> take me several evenings' tinkering with the source, whereas if I just did
> something else during that time it's half finished anyway. :) The isosurface
> floor could probably use a smaller max_gradient, I could certainly get away
> with a lower-res area_light, radiosity quality may well be too high, and I seem
> to recall that the default media sampling (which this uses) is unwise. Including
> the media seemed to produce the biggest slow-down... and, of course, merely
> activating the aa on a scene like this is a huge drag.

Um... yeah, if aside from area lights and radiosity you also did use isosurfaces
and media, then I'll keep my cake-hole shut :X

BTW, I don't agree with the other posters that the shot would look much better
with transparent material; you win the caustics, but I guess you lose a lot on
the shadow effect that this image shows off very impressively.

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Alain <aze### [at] qwertyorg> wrote:
> Did you use adaptive for your area_light?

I never use area lights without it!

> You may have inefecient bounding.

Good thought, but my objects are meshes, so I assume they are bounded optimally.

I blame the media ;-)

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"clipka" <nomail@nomail> wrote:
> Um... yeah, if aside from area lights and radiosity you also did use isosurfaces
> and media, then I'll keep my cake-hole shut :X

The isosurface isn't obvious (although probably more needed than in the other
image), but I would expect you to spot the media in the subsurface scattering
on those gems... :-D

> BTW, I don't agree with the other posters that the shot would look much better
> with transparent material; you win the caustics, but I guess you lose a lot on
> the shadow effect that this image shows off very impressively.

I thankyou. I may still try the glass version too though!

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"Bill Pragnell" <bil### [at] hotmailcom> wrote:
> Good thought, but my objects are meshes, so I assume they are bounded optimally.

In fact, "more than optimally" if there is such a thing :) (In addition to
having a fitting bounding box for the whole object, meshes use an internal
bounding hierarchy for the individual triangles.)

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"Bill Pragnell" <bil### [at] hotmailcom> wrote:
> "clipka" <nomail@nomail> wrote:
> > Um... yeah, if aside from area lights and radiosity you also did use isosurfaces
> > and media, then I'll keep my cake-hole shut :X
>
> The isosurface isn't obvious (although probably more needed than in the other
> image), but I would expect you to spot the media in the subsurface scattering
> on those gems... :-D

Now that you mention it...

.... honestly I still don't :}

Maybe it's one of those subtle things you only notice when it's missing, like in
"I can't really tell why, but the material doesn't look convincing to me"; and
maybe the 2000x2000 shot reveals it more clearly.

Anyway, I take that as a hint to get back into gear for further integration of
the experimental SSLT code :P

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Bill Pragnell wrote:
> "clipka" <nomail@nomail> wrote:
>> "Bill Pragnell" <bil### [at] hotmailcom> wrote:
>>> (took 140 hours to render at 2000x2000 - eek!)
>> Sounds to me like a case of "ur doin' it wrong": I see nothing in that shot that
>> would justify such a long render time.
> 
> Yes, it's entirely possible.

  I'm pretty certain that if instead of an isosurface you used a plane
with the proper normal block, you would get an almost identical image in
1/10th of the rendering time, if not even faster.

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