Insufficient coffee made me forget to ask about scaling and repeating the image
mapping by omitting once and perhaps doing other clever things...

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On 10-10-2014 15:45, Bald Eagle wrote:
> I might see if I can mesh model something, but I haven't really ever used a mesh
> modeler.  Not looking forward to making all those acanthus leaves and
> scrollwork...

Both methods (sdl or modeller) have their pro and cons. With both you 
need only to model a small part of the object and then copy 
 >mirror>paste that to obtain the final result, with the better 
alternative being: doing those last actions in POV-Ray. . I think that 
sdl would take a little more time to get there but the basic workflow is 
the same. For really complex models mesh2 models are to be preferred to 
sdl models as they can be significantly faster to render. However, that 
is less of an issue nowadays with faster PC's.

> A heightfield might give me something I could image map just to see if I like
> one particular design more than another.  Though a nicely shaded planar image
> map would likely serve the same purpose.

Yes, but you need a good quality height map for your height_field and 
that is a bit more difficult to achieve imo.

>
> Lastly, I was toying with cobbling together an SDL object that would mimic the
> gross contours of the object and then image map over that to quickly give a
> textured object with an actual 3D shape.  Worth doing?

Yes, worth the try if the object is not too prominent in the camera view.

>
> {"No, you dolt - use a modeler, or perform another blood sacrifice and be
> inculcated with the sacred power of POV SDL....")

I would do both, which means /two/ blood sacrifices of course as you 
need the infernal modeller powers too... ;-)

Thomas

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On 10-10-2014 16:09, Bald Eagle wrote:
> Insufficient coffee made me forget to ask about scaling and repeating the image
> mapping by omitting once and perhaps doing other clever things...
>

Hmm. If considering your image, which is circular, I guess you will need 
'once'...

Thomas

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Thomas de Groot <tho### [at] degrootorg> wrote:

> Hmm. If considering your image, which is circular, I guess you will need
> 'once'...

I was thinking that since it's circular, if I had it repeat across the surface
so that I had 2 full images, each hemispherical, then I could map it onto an
oblate spheroid and then bury it halfway into the ceiling.

So there.

With regard to blood sacrifice, clipka has slayed the Gamma Dragon, so now
THAT's not an option.  Somehow Spline Ducks don't quite have the same sense of
grandeur.  But then..  wait ...  yes!  The Stanford Chocolate Bunny!!!

Bring out the Holy Hand Grenade!

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On 10/10/14 15:48, Bald Eagle wrote:
> 
> Bring out the Holy Hand Grenade!
> 

And the LORD spake, saying, "First shalt thou take out the Holy Pin,
then shalt thou count to three, no more, no less.
Three shall be the number thou shalt count, and the number of the
counting shall be three.
Four shalt thou not count, neither count thou two, excepting that thou
then proceed to three.
Five is right out.
Once the number three, being the third number, be reached, then lobbest
thou thy Holy Hand Grenade of Antioch towards thy foe, who being naughty
in My sight, shall snuff it.

John (Bishop of Antioch)
-- 
Protect the Earth
It was not given to you by your parents
You hold it in trust for your children

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Am 10.10.2014 15:45, schrieb Bald Eagle:

> The counting still seems weird, like the way ACLU or Microsoft counts.  0, 1, 2,
> 5.  Who do I need to have induct me into the inner circle, what blood sacrifice
> needs to be made for me to pierce the veil of the Inner Mysteries of POV-Ray
> mapping codes?  Are those missing constants are only known to the 3&4th Degree
> Master Masons?  I'm guessing they map a _pyramidal_ sweep, or the obverse of
> worthless Federal Reserve Notes...

Well, the truth about those missing values is more along the profane 
Microsoft lines: They have been reserved for /some/ other fancy mappings 
since so long ago - without ever actually being implemented - that even 
the memory of /what/ mappings those were supposed to be is lost in the 
absorbing and scattering media of time.


> Lastly, I was toying with cobbling together an SDL object that would mimic the
> gross contours of the object and then image map over that to quickly give a
> textured object with an actual 3D shape.  Worth doing?

Worth trying at least.

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> Well, the truth about those missing values is more along the profane
> Microsoft lines: They have been reserved for /some/ other fancy mappings
> since so long ago - without ever actually being implemented - that even
> the memory of /what/ mappings those were supposed to be is lost in the
> absorbing and scattering media of time.

Yes, I've had a number of "This Space Reserved" issues.
Now if only I'd taken that 2 seconds to add the comment in the code...

This also makes me wonder of you can map things onto media....  :O


> Worth trying at least.

Touche'.

I've hand coded my ceiling lamps out of spheres, cylinders, cones, and sphere
sweeps, so now I'm going to take a whack at the medallion.  I might see if I
have enough interconnecting brain cells to plot pixels varying in grayscale
value with the sine of the distance from the origin, make that a heightfield,
and then slap my image map onto that...

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Am 10.10.2014 22:04, schrieb Bald Eagle:
>
>
>> Well, the truth about those missing values is more along the profane
>> Microsoft lines: They have been reserved for /some/ other fancy mappings
>> since so long ago - without ever actually being implemented - that even
>> the memory of /what/ mappings those were supposed to be is lost in the
>> absorbing and scattering media of time.
>
> Yes, I've had a number of "This Space Reserved" issues.
> Now if only I'd taken that 2 seconds to add the comment in the code...
>
> This also makes me wonder of you can map things onto media....  :O

Well, you can use patterns to control the density.


>> Worth trying at least.
>
> Touche'.
>
> I've hand coded my ceiling lamps out of spheres, cylinders, cones, and sphere
> sweeps, so now I'm going to take a whack at the medallion.  I might see if I
> have enough interconnecting brain cells to plot pixels varying in grayscale
> value with the sine of the distance from the origin, make that a heightfield,
> and then slap my image map onto that...

Function image, maybe? (You can generate an internal greyscale image 
from a function, and use that as input for a height field.)

Isosurface?

Parametric?

Lathe?

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

> Function image, maybe? (You can generate an internal greyscale image
> from a function, and use that as input for a height field.)

http://www.povray.org/documentation/view/3.6.0/379/
That was an option I was unaware of.  Too much cool stuff to play with!  :)

> Isosurface?
That could totally be a very cool option considering what I've seen people do
with isosurfaces.  Especially since it's a small scene element and so might not
be a huge bottleneck.

> Parametric?
> Lathe?

Both good suggestions I'll have to explore.

With regard to the complex topology of some of the furniture, I'm wondering if
something like a sphere sweep would get me the bulk of what I was aiming for
quickly - especially in the case of the scroll work.  IIRC, there's a "cone
sweep" - is there a cylinder sweep?  blob sweep?
I suppose those are all just specific instances of "follow this spline and plot
this object{X} at the current point", so I could try and code that generalized
case by hand...

Thanks for the suggestions as always.  There are few threads I fail to profit
from in some way.

{Have a great weekend everyone!}

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> Thomas de Groot <tho### [at] degrootorg> wrote:
>
>> Hmm. If considering your image, which is circular, I guess you will need
>> 'once'...
>
> I was thinking that since it's circular, if I had it repeat across the surface
> so that I had 2 full images, each hemispherical, then I could map it onto an
> oblate spheroid and then bury it halfway into the ceiling.
>
> So there.
>
> With regard to blood sacrifice, clipka has slayed the Gamma Dragon, so now
> THAT's not an option.  Somehow Spline Ducks don't quite have the same sense of
> grandeur.  But then..  wait ...  yes!  The Stanford Chocolate Bunny!!!
>
> Bring out the Holy Hand Grenade!
>
Take a simple sphere, unevently scalled, and simply apply your image to 
it as an image_map.
Something like this:

sphere{0, 1 scale <1,1, 0.2>
  pigment{
   image_map{ png "Medaillon1.png" translate -0.5 scale 2}
  rotate 90*x
  rotate y*Light_source_Fudge_Angle
  translate Final_Location
}

As the image is scaled to the same dimention as the sphere, you don't 
need to use once.

Now, you only need to make sure that it's correctly oriented relative 
the dominent light source so that the shadowings are coherent.

A beter way would be to create a hightfield of your medaillon and use 
water_level to cut out the base. That way, the shadows will always be 
correct.




Alain

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