I like the image itself, it's a very artistic-looking render. Like a painting.

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On 3/9/23 20:51, Kenneth wrote:
> I like the image itself, it's a very artistic-looking render. Like a painting.
> 

Thanks. :-)

I'll attach another I liked while playing. Same set up with complex 
functions, but much lower power exponents. Plus adding in some spiral 
action in the middle.

Another bit I stumbled across working with cf_pow() 'warping' is the 
effective change in scaling from the origin outward makes it pretty easy 
to set up images which change from a near constant color away from the 
origin to something where the f_hash()-ing is clear.

In other words, when the changes in region due the f_hash(), and/or 
higher cf_pow exponents, are happening at >>1 per pixel we end up with 
kind of an aggregate color. As we move to the origin things spread out 
and and we get a fade-in effect. FWIW, I guess, but neat. Hints at a 
possible general technique with on top of f_hash() for fading in or out 
of near constant colors.

Bill P.

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Attachments:
Download 'kaboomkeep3.jpg' (498 KB)

Preview of image 'kaboomkeep3.jpg'

Op 10-3-2023 om 11:08 schreef William F Pokorny:
> On 3/9/23 20:51, Kenneth wrote:
>> I like the image itself, it's a very artistic-looking render. Like a 
>> painting.
>>
> 
> Thanks. :-)
> 
> I'll attach another I liked while playing. Same set up with complex 
> functions, but much lower power exponents. Plus adding in some spiral 
> action in the middle.
> 
> Another bit I stumbled across working with cf_pow() 'warping' is the 
> effective change in scaling from the origin outward makes it pretty easy 
> to set up images which change from a near constant color away from the 
> origin to something where the f_hash()-ing is clear.
> 
> In other words, when the changes in region due the f_hash(), and/or 
> higher cf_pow exponents, are happening at >>1 per pixel we end up with 
> kind of an aggregate color. As we move to the origin things spread out 
> and and we get a fade-in effect. FWIW, I guess, but neat. Hints at a 
> possible general technique with on top of f_hash() for fading in or out 
> of near constant colors.
> 
> Bill P.
> 

Ooh! This one is nice! Going to download it: could be useful for 
something ;-)

-- 
Thomas

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On 3/10/23 07:11, Thomas de Groot wrote:
> Ooh! This one is nice! Going to download it: could be useful for 
> something 😉

:-) How about a POV-Ray, user ink blot test image?

"That Looks like an ink blot test," is what I thought on getting the 
result - and I'm never letting you all know I see in there! ;-)

Here again a complex function 'warp' acting on a small portion of a 
photograph; where I also used those undocumented / hidden, image_map, 
repeat and offset options.

Bill P.

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Attachments:
Download 'povrayinkblottest.jpg' (409 KB)

Preview of image 'povrayinkblottest.jpg'

Op 11-3-2023 om 10:17 schreef William F Pokorny:
> On 3/10/23 07:11, Thomas de Groot wrote:
>> Ooh! This one is nice! Going to download it: could be useful for 
>> something 😉
> 
> :-) How about a POV-Ray, user ink blot test image?
> 
> "That Looks like an ink blot test," is what I thought on getting the 
> result - and I'm never letting you all know I see in there! ;-)
> 
LOL! I wont either! ;-)

> Here again a complex function 'warp' acting on a small portion of a 
> photograph; where I also used those undocumented / hidden, image_map, 
> repeat and offset options.
> 
> 
Fascinating stuff indeed.

-- 
Thomas

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William F Pokorny <ano### [at] anonymousorg> wrote:
>
> :-) How about a POV-Ray, user ink blot test image?
>

That is really interesting and fabulous! I can imagine all sorts of
different-looking and visually unexpected results from using this technique.

One possible use would be for texturing the walls in a room-- like wall paper.
Or for creating designs for floor rugs and carpets.

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On 10/03/2023 00:39, William F Pokorny wrote:
> In the past few years Ingo, Tor Olav and others have played around with 
> include files supporting complex numbers for sound and images. Attached 
> is an image using a few of 30 plus inbuilt complex functions added to 
> the povr fork. Mostly just wrapping the complex functions coming with 
> C++11, but sometimes using function names more in line with the existing 
> complex includes and POV-Ray's function naming.
> 
> In povr, to work with the existing function vm, packing two 32 bit 
> floats into a double space as the complex value and all complex function 
> code runs at single float accuracy.
> 
> 

Sorry to re-open this old discussion. I didn't know this pov4 group exist :(


Anyway, i too have worked a lot in the world of complex numbers. I
started to write a macro library that implements complex functions using
povray "function".

And so: is "cfunctions.inc" just an encapsulation of C functions ?
Does v4 include a new data type like c = <re,im> with the possibility to
access c.re and c.im ?

I'm attaching my "complex_functions.inc" just in case ... I continue to
develop it or I wait for v4 ?

last thing : where can I find "cfunctions.inc" ?






-- 
Kurtz le pirate
Compagnie de la Banquise

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Attachments:
Download 'complex_functions.inc.txt' (34 KB)

hi,

kurtz le pirate <kur### [at] gmailcom> wrote:
> ...
> last thing : where can I find "cfunctions.inc" ?

installs as part of 'povr' branch (published in p.b.programming)


regards, jr.

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On 28/04/2023 16:10, jr wrote:
> hi,
> 
> kurtz le pirate <kur### [at] gmailcom> wrote:
>> ...
>> last thing : where can I find "cfunctions.inc" ?
> 
> installs as part of 'povr' branch (published in p.b.programming)
> 
> 
> regards, jr.
> 

Find. Thank jr

But as I suspected, the functions are just calls to internal functions.
so I will continue my work






-- 
Kurtz le pirate
Compagnie de la Banquise

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On 4/29/23 02:28, kurtz le pirate wrote:
>> hi,
>>
>> kurtz le pirate<kur### [at] gmailcom>  wrote:
>>> ...
>>> last thing : where can I find "cfunctions.inc" ?
>> installs as part of 'povr' branch (published in p.b.programming)
>>
>>
>> regards, jr.
>>
> Find. Thank jr
> 
> But as I suspected, the functions are just calls to internal functions.
> so I will continue my work
> 

Glad you found your path forward (jr, thanks for providing the pointer 
to the include file).

Thanks for posting your complex function include!

I'd looked at Tor Olav's and Ingo's include file efforts in this 
direction as I coded up the C++11 complex function wrappers, but I 
didn't have yours in hand. I've stored a copy as a reference in my work 
directory so I have it should I come back for more play.

Bill P.


--- Thinking aloud

One of the povr ideas / v4.0 suggestions I'm carrying around in my head 
is to drop the inbuilt fractal stuff - the julia shape and perhaps the 
julia, mandel and magnet patterns - as inbuilt code.

The julia shape is interesting, but aside from the pulled taffy shape 
most everyone seems to try, I don't see a common use for a julia shape 
in a ray tracer. I've taken shots at rendering some of the other 
julia-shape (sub-shapes) but I've not had luck finding anything I think 
useful to the mainstream. Plus, I've found the julia shape to be quite 
slow and glitchy.

The fractal patterns are more useful I think, but wish we'd not ended up 
with so many explicit versions (internally) for differing powers. I've 
not done any performance comparisons to the generic forms though...

I also don't know what I'm really doing in this area of POV-Ray - or 
with fractals in fact! Been holding off pulling it all from povr. This 
partly due finding recursive algorithm's - with which I'd had some luck 
back in the 2000s - to be pretty unstable today when I went to try some 
things recently...

I have in my head that I'd read somewhere there are fractal forms which 
are continuous? If so, these 'kinds' might make for more useful shapes / 
isosurfaces / patterns. But, yep! I'm just yapping. I don't know what 
I'm doing with respect to fractals...

Bill P.

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