High!

Several days have passed, and I tried to improve the appearance of my 
asteroidal moon, mostly be applying additional 3D noise to the surface 
(in the case of the image attached here, by replacing the original 
noise_3d(x, y, z) by noise_3d(pow(x, 3), pow(y, 3), pow(z, 3)), which in 
fact added subtle waves to the terrain relief).

But still the problem is, that with the crackle pattern (with form set 
to <n, 0, 0>), the craters are in fact "bubbles" of empty space 
distributed randomly inside the raw isosurface moon body and not 
necessarily cut in half by its surface, so that many craters still are 
gaping holes rather than shallow depressions.

How can I get rid of this? Is there something like UV mapping for 
isosurfaces which guarantees that only craters cut in half by the 
surface are generated?

Is it possible to write a "core function" which, on the x-y plane, 
generates a roughly symmetric (perhaps slightly turbulated) 
cross-section of a crater, with terraced walls, a rim higher than the 
surrounding terrain and even a central peak, which then is transferred 
to a circular structure by applying trigonometric functions (?), which 
in turn are distributed randomly (also with random variations in depth, 
diameter, terracing and height of central peak) across the existing 
asteroid surface?

Where can I find the mathematical resources to design such a function?

See you in Khyberspace!

Yadgar

Now playing: Pirates of Love (Zara)

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Attachments:
Download '2006-06-24 michatopia, moon .jpg' (20 KB)

Preview of image '2006-06-24 michatopia, moon .jpg'

Jörg 'Yadgar' Bleimann wrote:

> High!
> 
> [...]
> How can I get rid of this? Is there something like UV mapping for
> isosurfaces which guarantees that only craters cut in half by the
> surface are generated?

You could create the isosurface without holes then use trace() and
difference out the craters, but that doesn't help with the rims.

You could use trace and a blob rather than an isosurface, but again
the rims are tricky (or impossible).

You might be able to add the crackle pigment as a function to
the isosurface, but I'm not sure how that would turn out.

> Is it possible to write a "core function" which, on the x-y plane,
> generates a roughly symmetric (perhaps slightly turbulated)
> cross-section of a crater, with terraced walls, a rim higher than the
> surrounding terrain and even a central peak, which then is transferred
> to a circular structure by applying trigonometric functions (?), which
> in turn are distributed randomly (also with random variations in depth,
> diameter, terracing and height of central peak) across the existing
> asteroid surface?
> 
> Where can I find the mathematical resources to design such a function?
> 
> See you in Khyberspace!
> 
> Yadgar
> 
> Now playing: Pirates of Love (Zara)

-- 
Bill Hails
http://billhails.net/

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High!

Bill Hails wrote:

> You could create the isosurface without holes then use trace() and
> difference out the craters, but that doesn't help with the rims.

Interesting approach... perhaps I would even be able to generate halfway 
believable rims!

> You might be able to add the crackle pigment as a function to
> the isosurface, but I'm not sure how that would turn out.

This is exactly what I did in my current attempts!

See you in Khyberspace!

Yadgar

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Jörg 'Yadgar' Bleimann wrote:
> High!
> 

For future reference, when greeting people in English, the proper 
spelling of it is "Hi!" not "High!"  They are both pronounced the same, 
but the meanings are completely different.

Just thought you might like to know.  I understand we have a lot of 
people here that speak English as a second, or even third or fourth 
language, and I most of them want to be told when they say something 
wrong or that doesn't make sense.

-DJ

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Thought I'd have a go at this one...

// Asteroid
#version 3.6;
// ==============================================================
#default{finish{ambient 0}}
#global_settings{assumed_gamma 1.0 max_trace_level 5}

#declare f_bozo1 = // similar to noise3d
function{pigment{bozo scale 0.5 color_map{[0 color rgb 0] [1 color rgb 1]}}}

#declare f_craters =
function{
  pigment{
    crackle form <1.2, 0, 0> // never really played with this one, thaks
Yadgar!
    scale 0.3
    color_map{
      [0.00 color rgb 1.00] // centre of crater, lowest part
      [0.30 color rgb 0.80] //
      [0.35 color rgb 0.40] // rim, higher than surrounding area
      [0.40 color rgb 0.5] // level of area outside the crater
      [1.00 color rgb 0.5]
    }
  }
}

/*
the f_craters function is subtracted from the basic asteroid shape, so the
lowest points get the highest numbers, since you are subtracting more.
*/

// --------------------------------------------------------------
isosurface{
  function{
    (x*x)+(y*y*1.8)+(z*z*1.5)-1 // basic sphere function, scaled to be more
elliptical
    +f_bozo1(x,y,z).red*0.35 // deforms the ellipse shape
    +f_craters(x,y,z).red*0.05 // adjust the '*0.05' part to change the
depth of the craters
  }
  contained_by{box{<-1, -1, -1>, <1, 1, 1>}}
  threshold 0
  accuracy 0.001
  max_gradient 4
  texture{pigment{color rgb 1} finish{diffuse 0.6}}
}

light_source{<-10, 10, -5> color rgb 1}
light_source{< 10, -10, -5> color rgb<0.2, 0.4, 1.0>*0.25}

camera{
  location <0, 1, -4>
  up y*(image_height/image_width)
  right x
  sky y
  look_at <0, 0, 0>
  angle 36
}
// -------------------------------------------------- end of file

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Attachments:
Download 'asteroid.jpg' (6 KB)

Preview of image 'asteroid.jpg'

A potato-cheese with holes! Delicious! Nyam!



Doesn't looks very realistic. Might be, the crater edges are to straight. 
And the entire object (asteroid and craters) is too regular, somehow. Not in 
shape, but in surface characteristica. Too plain. Too smooth.

I believe you would be well-advised to consult photos of asteroid or moons 
surfaces to get some good ideas. Surfaces are not really plain but bear tiny 
difference in surface heights and surface roughness.

But your project is promising. Go on, and you will create a great model of 
an asteroid!

Greetings,

Sven

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High! ;-))

> For future reference, when greeting people in English, the proper spelling 
> of it is "Hi!" not "High!"

Of course I know... but I use "High!" deliberately as a kind of oxymoron to 
indicate my preferred state of mind , which is, by the way, not induced by 
any chemical additives, but by such mindblowing things like raytracing, 
electronic organs, extrasolar planets and Afghanistan!

See you in Khyberspace!

Yadgar

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High!

Sven Littkowski wrote:

> I believe you would be well-advised to consult photos of asteroid or moons 
> surfaces to get some good ideas. Surfaces are not really plain but bear tiny 
> difference in surface heights and surface roughness.

Yes, I've seen this on close-up NEAR photos of (433)Eros... and I had 
some headache to find out how to add such small-scale noise to the 
surface! Should I try noise_generator_3d rather than noise_3d?

See you in Khyberspace!

Yadgar

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Jörg 'Yadgar' Bleimann nous apporta ses lumieres en ce 26/06/2006 16:38:
> High!
> 
> DJ Wiza wrote:
> 
>> For future reference, when greeting people in English, the proper 
>> spelling of it is "Hi!" not "High!"  They are both pronounced the 
>> same, but the meanings are completely different.
> 
> Of course I know... but I deliberately use "High!" as a little pun to 
> indicate my favourite state of mind... which, by the way, is not induced 
> by hemp products, but by such mindblowing things and experiences like 
> raytracing, electronic organs, extrasolar planets, swamp mud orgies and 
> Afghanistan!
> 
> See you in Khyberspace!
> 
> Yadgar
> 
> P. S. Micro$oft Outlook Express sucks!!! I tried to post this already 
> this afternoon (CET) from a workplace computer, which of course runs 
> under Windoze... but it didn't show up at all on the server!
Still using Thunderbird 1.0! That's an antique. Newest is 1.5.0.4.
Both of your messages made it trough.

-- 
Alain
-------------------------------------------------
Never delay the ending of a meeting or the beginning of a cocktail hour.

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Dr. Egon Kasper wrote:
> High! ;-))
> 
>>For future reference, when greeting people in English, the proper spelling 
>>of it is "Hi!" not "High!"
> 
> Of course I know... but I use "High!" deliberately as a kind of oxymoron to 
> indicate my preferred state of mind , which is, by the way, not induced by 
> any chemical additives,

'Lo...     ;-)

I always understood your "High" that way.

>                          but by such mindblowing things like raytracing, 
> electronic organs, extrasolar planets and Afghanistan!
> 
> See you in Khyberspace!
> 
> Yadgar 

Besides raytracing and computers, I've always been particularly 
fascinated by pipe organs -- both classic/church style and theater style 
-- and their appropriate music.  (These pipe organ styles are quite 
different both in their sound and in their construction.)

      -=- Larry -=-

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I added a few more layers of detail, and some turbulence to the bozo
pigment.  I think it looks much more 'asteroidy' now, and less like an
unfortunate vegetable.

Post a reply to this message

Attachments:
Download 'asteroid.jpg' (32 KB)

Preview of image 'asteroid.jpg'

Mark Birch wrote:
> I added a few more layers of detail, and some turbulence to the bozo
> pigment.  I think it looks much more 'asteroidy' now, and less like an
> unfortunate vegetable.

Absolutely; bravo.

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High!

Larry Hudson wrote:

> Besides raytracing and computers, I've always been particularly 
> fascinated by pipe organs -- both classic/church style and theater style 
> -- and their appropriate music.  (These pipe organ styles are quite 
> different both in their sound and in their construction.)

Ah, theatre organs... have you heard this: 
http://www.hauptwerk.co.uk/AudioDemos/Hauptwerk2-MDAWurliTzer1.mp3 ?

Its from the famous Hauptwerk virtual organ project site... really 
groovy sound, I just imagine Richard Rodgers' famous "Slaughter on Tenth 
Avenue" being played on such an organ...

But my interest in organs currently focuses on 70s analogue electronic 
organs (of which of course quite a lot models were built in theatre 
style, for example the Dutch-made Eminent Grand Theatre series, or large 
Kimball organs such as the famous-infamous Xanadu) and of course classic 
electro-magnetic Hammonds.

B-3s are not exactly affordable these days, but at least I own two 70s 
transistorized analogue organs, a budget-class Eminent and a 
middle-class Yamaha (those Japanese organs are just indestructible and 
doing well even after 30 years!). But I still hope to get myself a 
Technics SX-U90 some day... the "dream ship" of my teenage days!

The small Eminent (a Solina P-240) I even started to model with PoV-Ray...

See you in Khyberspace!

Yadgar

Now playing: Is it Love? (Jon and Vangelis)
Now practising: Mr. Sandman

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High!

Mark Birch wrote:
> I added a few more layers of detail, and some turbulence to the bozo
> pigment.  I think it looks much more 'asteroidy' now, and less like an
> unfortunate vegetable.

Awesome... shows me how long a way I still have to go! But how long did 
it take to render?

See you in Khyberspace!

Yadgar

Now playing: Back to School (Jon and Vangelis)

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> Awesome... shows me how long a way I still have to go! But how long did
> it take to render?
>

Rendered in 2min 14s at 512x384 on a 1.8GHz P4 (no antialiasing).
Antialiasing slows it down quite alot, depending on settings.
I think the version I posted took about 8min with +am1 +a0.3

Here is the code:

// Asteroid
#version 3.6;
// ==============================================================
#default{finish{ambient 0}}
#global_settings{assumed_gamma 1.0 max_trace_level 5}

#declare f_bozo1 = // similar to noise3d
function{
  pigment{
    bozo
    noise_generator 3
    scale 0.35
    turbulence 0.30
    color_map{
      [0 color rgb 0]
      [1 color rgb 1]
    }
  }
}

#declare f_craters =
function{
  pigment{
    crackle form <1.2, 0, 0> // never really played with this one, thaks
Yadgar!
    turbulence 0.1 omega 0.6
    scale 0.15
    color_map{
      [0.00 color rgb 1.00] // centre of crater, lowest part
      [0.25 color rgb 0.75]
      [0.33 color rgb 0.25]
      [0.40 color rgb 0] // crater rim
      [1.00 color rgb 0] // level of area outside the crater
    }
  }
}

#declare f_granite =
function{
  pigment{
    granite
    scale 0.08
    color_map{
      [0 color rgb 0]
      [0.5 color rgb 0]
      [1 color rgb 1]
    }
  }
}

// --------------------------------------------------------------
isosurface{
  function{
    (x*x)+(y*y*2.2)+(z*z*1.5)-1
    +f_bozo1(x,y,z).red*0.300
    +f_craters(x,y,z).red*0.030
    +f_craters(x*2,y*2,z*2).red*0.020
    +f_granite(x,y,z).red*0.01
  }
  contained_by{box{<-1, -1, -1>, <1, 1, 1>}}
  threshold 0
  accuracy 0.005
  max_gradient 7.5
  texture{
    pigment{color rgb 1}
    finish{diffuse 1 brilliance 2}
  }
}

light_source{<-10, 10, 5> color rgb 1.5}
light_source{< 10, -10, -5> color rgb<0.2, 0.5, 1.0>*0.15}

camera{
  location <0, 1, -4>
  up y*(image_height/image_width)
  right x
  sky y
  look_at <0, 0, 0>
  angle 36
}
// -------------------------------------------------- end of file

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Jörg 'Yadgar' Bleimann wrote:

> Ah, theatre organs... have you heard this: 
> http://www.hauptwerk.co.uk/AudioDemos/Hauptwerk2-MDAWurliTzer1.mp3 ?

Love it!  :-)

> Its from the famous Hauptwerk virtual organ project site... really 
> groovy sound, I just imagine Richard Rodgers' famous "Slaughter on Tenth 
> Avenue" being played on such an organ...

I do have an old, monophonic recording of George Wright playing 
Slaughter, but at the moment I don't recall what specific organ it was on.

I'm attaching a photo of myself at my (electronic) organ.  I have fun 
with this picture, it's surprising how many people don't "get it". 
(Hint, it's a paste-up -- two shots cut and pasted then recopied.  I did 
this long before I had a computer, let alone, any graphics editor.)

      -=- Larry -=-

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Attachments:
Download 'organ.jpg' (148 KB)

Preview of image 'organ.jpg'

Larry Hudson wrote:
> 
> I'm attaching a photo of myself at my (electronic) organ.  I have fun
> with this picture, it's surprising how many people don't "get it".
> (Hint, it's a paste-up -- two shots cut and pasted then recopied.  I did
> this long before I had a computer, let alone, any graphics editor.)

It reminds me of one of the Naked Gun -movies. I think it's 2½, but
could also be 1.

-- 
Eero "Aero" Ahonen
   http://www.zbxt.net
      aer### [at] removethiszbxtnetinvalid

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just followed this thread for a while, and as I'd a little time
yesterday evening, I played around with different layers and came up
with this one.

Still some texture issues. Maybe I'll try to add some normals as well.

...dave


Jörg 'Yadgar' Bleimann schrieb:
> High!
> 
> Several days have passed, and I tried to improve the appearance of my
> asteroidal moon, mostly be applying additional 3D noise to the surface
> (in the case of the image attached here, by replacing the original
> noise_3d(x, y, z) by noise_3d(pow(x, 3), pow(y, 3), pow(z, 3)), which in
> fact added subtle waves to the terrain relief).
> 
> But still the problem is, that with the crackle pattern (with form set
> to <n, 0, 0>), the craters are in fact "bubbles" of empty space
> distributed randomly inside the raw isosurface moon body and not
> necessarily cut in half by its surface, so that many craters still are
> gaping holes rather than shallow depressions.
> 
> How can I get rid of this? Is there something like UV mapping for
> isosurfaces which guarantees that only craters cut in half by the
> surface are generated?
> 
> Is it possible to write a "core function" which, on the x-y plane,
> generates a roughly symmetric (perhaps slightly turbulated)
> cross-section of a crater, with terraced walls, a rim higher than the
> surrounding terrain and even a central peak, which then is transferred
> to a circular structure by applying trigonometric functions (?), which
> in turn are distributed randomly (also with random variations in depth,
> diameter, terracing and height of central peak) across the existing
> asteroid surface?
> 
> Where can I find the mathematical resources to design such a function?
> 
> See you in Khyberspace!
> 
> Yadgar
> 
> Now playing: Pirates of Love (Zara)
> 
> 
> ------------------------------------------------------------------------
>

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Attachments:
Download 'asteroid_01_800x600.jpg' (42 KB)

Preview of image 'asteroid_01_800x600.jpg'

Larry Hudson <org### [at] yahoocom> wrote:
> I'm attaching a photo of myself at my (electronic) organ.  I have fun
> with this picture, it's surprising how many people don't "get it".
> (Hint, it's a paste-up -- two shots cut and pasted then recopied.  I did
> this long before I had a computer, let alone, any graphics editor.)
>
>       -=- Larry -=-

WOW!  I bet you're a great drummer too!  I can hear some pretty complex
syncopation with three hands!

RG

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High!

Larry Hudson wrote:

> I'm attaching a photo of myself at my (electronic) organ.  I have fun 
> with this picture, it's surprising how many people don't "get it". 
> (Hint, it's a paste-up -- two shots cut and pasted then recopied.  I did 
> this long before I had a computer, let alone, any graphics editor.)

...but the third manual is real, isn't it? What brand is it - a Baldwin 
or a Wurlitzer?

See you in Khyberspace!

Yadgar

Now playing: Underpass (John Foxx)

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Jörg 'Yadgar' Bleimann wrote:
> High!
> 
> Larry Hudson wrote:
> 
>> I'm attaching a photo of myself at my (electronic) organ.  I have fun 
>> with this picture, it's surprising how many people don't "get it". 
>> (Hint, it's a paste-up -- two shots cut and pasted then recopied.  I 
>> did this long before I had a computer, let alone, any graphics editor.)
> 
> 
> ...but the third manual is real, isn't it? What brand is it - a Baldwin 
> or a Wurlitzer?
> 
> See you in Khyberspace!
> 
> Yadgar
> 
> Now playing: Underpass (John Foxx)

Yes it is a real three-manual organ.  An uncommon make -- Artisan. 
Believe it or not, it was a kit, and I built myself.  It was a two to 
three year project, because you could buy it a piece at a time.  The 
console was complete, but I did all the electronics and wiring in it. 
Unfortunately, this brand is no longer available.  But it _was_ a fun 
project.

      -=- Larry -=-

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High!

Larry Hudson wrote:

> Yes it is a real three-manual organ.  An uncommon make -- Artisan. 
> Believe it or not, it was a kit, and I built myself.  It was a two to 
> three year project, because you could buy it a piece at a time.

Artisan - never heard of it! But organ kits are familiar to me, as here 
in Germany, from the 60s to the early 80s they were also pretty common - 
perhaps you have heard of the German organ kit companies Wersi and Dr. 
Böhm! Even I easily could have ended up as a kit organ builder in my 
teens - but instead decided to buy me a Commodore 64 rather than a Wersi 
Orion kit!

Wersi still exists, but now they sell only ready-made (and very 
expensive) organs, as nowadays except for some analogue organ fanatics 
nobodys want to take on year-long construction work in the hobby 
basement room!

   The
> console was complete, but I did all the electronics and wiring in it. 
> Unfortunately, this brand is no longer available.  But it _was_ a fun 
> project.

With Hammond-like drawbars or more theatre-style?

As I just mentioned analogue organ fanatics - there exists a forum 
dedicated to analogue electr(on)ic organs from Hammond's A series to 
mid-80s semi-digital Technicses and Yamahas: http://www.analogorgel.de - 
it's mostly German-spoken, but speakers of English are equally welcome, 
we also have an English sub-forum!

Perhaps we can meet there and talk organs...

See you in Khyberspace!

Yadgar

Now playing: One Vision (Queen)

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Jörg 'Yadgar' Bleimann wrote:
> High!
> 
> Larry Hudson wrote:
> 
>> Yes it is a real three-manual organ.  An uncommon make -- Artisan. 
>> Believe it or not, it was a kit, and I built myself.  It was a two to 
>> three year project, because you could buy it a piece at a time.
> 
> Artisan - never heard of it! But organ kits are familiar to me, as here 
> in Germany, from the 60s to the early 80s they were also pretty common -

It was a pretty small company, located in Pasadena, California -- about 
70 miles from where I live, Ventura.  (Actually, it was Altadena, which 
is "next door" to Pasadena.)

> perhaps you have heard of the German organ kit companies Wersi and Dr. 
> Böhm! Even I easily could have ended up as a kit organ builder in my 
> teens - but instead decided to buy me a Commodore 64 rather than a Wersi 
> Orion kit!

I seem to recall hearing the Wersi name, but I'm not familiar with them. 
  As to organs vs computers, after I got the computer bug I've kinda let 
the organ go.  I rarely touch it anymore, and I never was able to play 
very well anyway.  (What's more, right now it's BADLY out of tune.) 
:-(   Still love to listen to them, of course.

My first computer was an Altair (remember them?).  That's the one that 
first really started the PC "revolution".  Of course, they weren't 
called PCs back then.  The Altair was first described in the January 
1975 issue of Popular Electronics magazine.  I got mine around September 
or October that year.  (It had all of 1K of memory!)

>> console was complete, but I did all the electronics and wiring in it. 
>> Unfortunately, this brand is no longer available.  But it _was_ a fun 
>> project.
> 
> 
> With Hammond-like drawbars or more theatre-style?

Definitely theater-style, but with classic-style voicing instead.
Personally, I've always disliked the Hammond drawbar sound.  As I 
mentioned earlier, my main interest is pipe organs, so I only like 
electronic organs that try to simulate pipes.  Hammonds have their own 
unique sound which doesn't appeal to me.  I do like synthesizers though, 
but they're an entirely different class of instrument.  One unsual 
recording I have is the COMPLETE Ravel Bolero on synthesizer. 
Fascinating.  (And somewhat amusing because it ends with synthesized 
audience applause, complete with whistling and such.)   :-)

> As I just mentioned analogue organ fanatics - there exists a forum 
> dedicated to analogue electr(on)ic organs from Hammond's A series to 
> mid-80s semi-digital Technicses and Yamahas: http://www.analogorgel.de - 
> it's mostly German-spoken, but speakers of English are equally welcome, 
> we also have an English sub-forum!
> 
> Perhaps we can meet there and talk organs...

Hmmm...  I might check it out.  Also, I think this thread should be 
moved to the povray off-topic as well.  But so far, I've never bothered 
with reading that group.  Let me know if you want to continue there, and 
I will start looking into the OT group.

> See you in Khyberspace!
> 
> Yadgar
> 
> Now playing: One Vision (Queen)

      -=- Larry -=-

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Message to Jörg 'Yadgar' Bleimann

I have a Technics SXU-90 I have to say goodbye to.  Do you want it?
email me : Pau### [at] brisbaneqldgovau

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