dlm wrote:

> Quite pleasing!.

Thanks!

> "Bill Hails" <bil### [at] europeyahoo-inccom> wrote in message
> news:4282738c@news.povray.org...
>> Hi, back to basics.
>>
>> Lathes and procedural textures/materials
>>
>> 1. I have no idea yet how to mould a handle and a spout
>> onto the teapot, but I hope I'll figure something out.
>>
>> 2. There's something not quite right about the china, too
>> "soft"? but I don't know how to improve it.
> Your china is porcelain. Heavy duty cafeteria porcelain. Fine bone china
> is whiter, thinner and somewhat translucent.

I should have said porcelain, sorry. I still don't think it looks quite
right, something makes it appear like I'm using focal blur when I'm not,
esp. the top right cup.

> Of course you might have something else in mind, like "the Utah teapot"
> http://www.sjbaker.org/teapot/

I knew it existed, thanks for the link. I did say "back to basics"
so the connection had occurred to me, However I'm lucky enough to
work very near London's Chinatown, and many of the cafe's serve
tea in these elegant tea services, so I bought one from a local
Chinese shop and brought it home to model it (and enjoy the tea).

> 
> 
>>
>> 3. I'm quite happy with the wood texture, but I could take
>> it further.
> Nice.

I was thinking some localised abrasion might help.

>>
>> 4. I realise the bubble in the tea looks fake, I'll work more
>> on that.
> What bubble? ior=1?
> The meniscus is nicely modelled.

bubble is difference { union { object { Tea } sphere } sphere }
meniscus is difference { object { Tea } union { cylinder torus scale <R, 1, 
R> } }

>>
>> My big question is, I'd like to get some turbulence and
>> variation in the colour of the tea, especially around the
>> tea leaves, due to convection, but again I'm at a loss.
> Turbulence. Do you mean something like a fractal volume with a lower ior?

yeah, f_noise3d or f_ridged_mf might do it, if I subtract lots of it
from a sphere around the tealeaves.

> Color variation. You're looking to see a pigment density gradient in the
> vicinity of the leaves?

more of a "fire" or "smoke" effect as the pigment seeps out of the leaves.
I have noticed the effect while drinking tea and modelling :-)

> What kind of tea is that pink?

It looked pretty close to the tea I was drinking at the time.

> Steam/media above the surface?

maybe, but every element I add is another element I have to get right,
hopefully the turbulence in the liquid will be enough to suggest heat.

> Apart from the edges where there is a clear color intensity gradient, the
> bulk of the tea has a very uniform color.
> With a light absorbing medium the intensityyou expect the Beer-Lambert law
> to operate
> A=ECd where A=-log10(transmission), E is the extinction coefficient, C is
> the concentration of the absorbing solute and d is the length of the
> optical path.
> Given all that, the tea at the bottom of the cup should be darker.

I just took it from the manual:

"If you set fade_power in the interior of an object at 1000 or above, a 
realistic exponential attenuation function will be used:

 
  Attenuation = exp(-depth/fade_dist)"
 
> Looking forward to another cup...

Thanks very much for your comments.

> 
> DLM
> 
> 
>>
>> I'd appreciate any helpful criticisms, I can post source
>> for the textures if anyone's interested.
>>
>> --
>> Bill Hails
>> http://thyme.homelinux.net/

-- 
Bill Hails
http://thyme.homelinux.net/

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