Warp <war### [at] tagpovrayorg> wrote:
>   I think a simple plane with a proper normal block would have resulted
> in a practically identical image but much faster.

Would the shading due to the caustics still be correct?

In any case, using an isosurface instead of a plane didn't slow it down that
much. And I just can't help thinking of normals as 'cheating' ;-)

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Bill Pragnell wrote:
> Would the shading due to the caustics still be correct?

  Why wouldn't it?

> In any case, using an isosurface instead of a plane didn't slow it down that
> much. And I just can't help thinking of normals as 'cheating' ;-)

  Everything is "cheating" in rendering. It's just smart to use the
cheats which will produce the same results faster.

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> Bit quiet on p.b.i. at the moment, so here's some shiny things.
> 
> These are the Platonic, Archimedean and Catalan solids. How many can you name
> without resorting to wikipedia or wolfram? :-)
> 
> 
> 
> ------------------------------------------------------------------------
> 
Really nice, as usual ;-)

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Warp <war### [at] tagpovrayorg> wrote:
> Bill Pragnell wrote:
> > Would the shading due to the caustics still be correct?
>
>   Why wouldn't it?

Well, if my isosurface were more deeply ridged, there'd be shadowed areas in the
photon maps that normals wouldn't produce. But this probably isn't happening
here, I ended up with very shallow features.

Aside from that, I just assumed that the normal block wouldn't be used when
applying photon maps to surfaces. For no good reason, other than that normals
aren't used in radiosity unless specified. I can't find any mention of it in
the docs. I'll try it later, then I'll know... :)

>   Everything is "cheating" in rendering. It's just smart to use the
> cheats which will produce the same results faster.

True. At least (in general) cheating with actual geometry is a little closer to
reality. But I agree it would seem to make little or no difference in this
case.

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Darren New wrote:
> Bill Pragnell wrote:
>> Bit quiet on p.b.i. at the moment, so here's some shiny things.
> 
> Ooooooo!  A spaaaarkly!
> 

LOL

-- 
~Mike

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"Bill Pragnell" <bil### [at] hotmailcom> wrote:
> Bit quiet on p.b.i. at the moment, so here's some shiny things.
>

Very, very beautiful! Especially the lighting and the colored shadows. I tried
something similar with a simple glass sphere and photons a few weeks ago, but
the shadow was much too dark. Maybe the "count" was too low. I'm not so
experienced with glass like objects, because I have frustrating results most of
the time and therefore don't really dare to raytrace them often ...
But now with this proof, that they can look really good, I will try again
sometime in the future.

> These are the Platonic, Archimedean and Catalan solids. How many can you name
> without resorting to wikipedia or wolfram? :-)

.... dodecahedron, icosahedron ... uhm ...

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On Wed, 24 Jun 2009 16:45:35 -0400, Bill Pragnell wrote:

> Bit quiet on p.b.i. at the moment, so here's some shiny things.

Shiny!  I like the textures & colours.... :-)

Reminds me a lot of the polyhedral dice I have around ehre somewhere.

Jim

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"Simone" <inf### [at] alienenterprisesde> wrote:
> Very, very beautiful! Especially the lighting and the colored shadows.

Thank you!

> I tried
> something similar with a simple glass sphere and photons a few weeks ago, but
> the shadow was much too dark. Maybe the "count" was too low.

The shadows are bright in my image because I used radiosity with a bright
environment, so there are no completely shadowed areas. However, if you have a
sphere and a single light source, a largely dark shadow with a single bright
spot is to be expected. It only looks odd because you don't often get that
lighting setup in reality.

Having said that, count does need to be fairly high to get good results. I
typically use at least 1e6, but 1e4-1e5 could be sufficient for something
really simple like a sphere.

> I'm not so
> experienced with glass like objects, because I have frustrating results most of
> the time and therefore don't really dare to raytrace them often ...
> But now with this proof, that they can look really good, I will try again
> sometime in the future.

Sometimes, the knowledge that something can be done is all the motivation you
need to work out how to do it. :)

Bill

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> "Bill Pragnell" <bil### [at] hotmailcom> wrote:
>> Bit quiet on p.b.i. at the moment, so here's some shiny things.
>>
> 
> Very, very beautiful! Especially the lighting and the colored shadows. I tried
> something similar with a simple glass sphere and photons a few weeks ago, but
> the shadow was much too dark. Maybe the "count" was too low. I'm not so
> experienced with glass like objects, because I have frustrating results most of
> the time and therefore don't really dare to raytrace them often ...
> But now with this proof, that they can look really good, I will try again
> sometime in the future.
> 
>> These are the Platonic, Archimedean and Catalan solids. How many can you name
>> without resorting to wikipedia or wolfram? :-)
> 
> .... dodecahedron, icosahedron ... uhm ...
> 
> 
> 
When tracing a sphere with photons, it's normal to get a (very) dark 
shadow with a bright spot in the center. If the sphere is to far away 
from the surface receiving the shadow, the photons will have converged 
to the focal point and spread again, possibly to an area much larger 
than the sphere.

Glass objects, as well as metallic ones, need some environment to look 
good. You also need something to get some light in the shadowed areas. 
It can be a shadowless light source set to NOT cast photons, or it can 
be radiosity.

Photons block for a fill light:
photons{refraction off reflection off}


Alain

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Alain wrote:
> Glass objects, as well as metallic ones, need some environment to look
> good. You also need something to get some light in the shadowed areas.
> It can be a shadowless light source set to NOT cast photons, or it can
> be radiosity.

  Or simply use multiple light sources. A single light source,
especially in "interior" scenes, tends to look a bit dull (although it
can be used effectively as well).

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