Not sure on policy for photo/raytrace composites, so I won't
post the actual image here. I'm quite pleased with it though:

http://billhails.net/Gallery/visitor.html

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

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I'm having trouble figuring out which bit *isn't* real... which is the 
idea, presumably. ;-)

Post a reply to this message

Orchid XP v2 wrote:

> I'm having trouble figuring out which bit *isn't* real... which is the
> idea, presumably. ;-)

Thanks! that's precisely the idea of course. I personally don't have
a problem with images of this type, though this one was really just
a proof of concept using an existing model from an earlier pic.

I really love the idea of making something that's obviously impossible
appear real, I guess lots of people into raytracing have the same
instinct.

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

Post a reply to this message

Bill Hails wrote:
> Orchid XP v2 wrote:
> 
> 
>>I'm having trouble figuring out which bit *isn't* real... which is the
>>idea, presumably. ;-)
> 
> 
> Thanks! that's precisely the idea of course. I personally don't have
> a problem with images of this type, though this one was really just
> a proof of concept using an existing model from an earlier pic.
> 
> I really love the idea of making something that's obviously impossible
> appear real, I guess lots of people into raytracing have the same
> instinct.
> 
This was the earliest impetus for developing raytracing techniques I 
believe.  At any rate it is a lovely image.  I wonder if that lovelyness 
is part of what may seem not quite believeable bacause what we have is 
beautiful, delicate, diffuse, space-creating natural light, together 
with frozen motion.

Post a reply to this message

Jim Charter wrote:

> Bill Hails wrote:
>> Orchid XP v2 wrote:
>> 
>> 
>>>I'm having trouble figuring out which bit *isn't* real... which is the
>>>idea, presumably. ;-)
>> 
>> 
>> Thanks! that's precisely the idea of course. I personally don't have
>> a problem with images of this type, though this one was really just
>> a proof of concept using an existing model from an earlier pic.
>> 
>> I really love the idea of making something that's obviously impossible
>> appear real, I guess lots of people into raytracing have the same
>> instinct.
>> 
> This was the earliest impetus for developing raytracing techniques I
> believe.  At any rate it is a lovely image.  I wonder if that lovelyness
> is part of what may seem not quite believeable bacause what we have is
> beautiful, delicate, diffuse, space-creating natural light, together
> with frozen motion.

Thanks Jim, insightful as ever.

I think I figured out a few things that detract from a perfectly
natural image.

Firstly I didn't really pay any attention to the relative camera
perspectives of the photo and the render, they should coincide
for a believable image, I mean if the photo is with a 50mm lens,
then the render should try to emulate the same angle of view.

Secondly the light intensity isn't correlated, I should take into
account how much light the (real) mirrorball actually reflects,
probably no more than 70% or so.

Thirdly, I had to scale the render somewhat to fit the photo, better
to render at the correct size in the first place.

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

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> I really love the idea of making something that's obviously impossible
> appear real, I guess lots of people into raytracing have the same
> instinct.

This is the entire purpose of raytracing! :-D

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It doesn't seem to be casting much shadow on the room objects and lacking a
reflection in the window, but I'm just nitpicking :).

Otherwise, well done.

Post a reply to this message

"Mienai" <Mienai> wrote:

> It doesn't seem to be casting much shadow on the room objects and lacking
> a reflection in the window, but I'm just nitpicking :).
> 
> Otherwise, well done.

Yes, the interaction is all one way of course. The standard solution
I believe would be to start to model other parts of the scene to allow
the object to cast shadows and reflections, but that's starting to feel
like hard work for just a PoC.

Next I'm going to hover a 30 foot flying saucer over our back lawn :-)

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

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"Bill Hails" <me### [at] billhailsnet> schreef in bericht
news:44435f98@news.povray.org...
> Next I'm going to hover a 30 foot flying saucer over our back lawn :-)
>
Oh dear!!! I have always dreamed of doing that...really!!!!  :-)
Nice image, Bill!

Thomas

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"Bill Hails" <me### [at] billhailsnet> schreef in bericht
news:44435f98@news.povray.org...
> Next I'm going to hover a 30 foot flying saucer over our back lawn :-)
>
Looking out of my window, I just got one!!!

Thomas

Post a reply to this message

Attachments:
Download 'flyingsaucer.jpg' (8 KB)

Preview of image 'flyingsaucer.jpg'

Thomas de Groot wrote:

> 
> "Bill Hails" <me### [at] billhailsnet> schreef in bericht
> news:44435f98@news.povray.org...
>> Next I'm going to hover a 30 foot flying saucer over our back lawn :-)
>>
> Looking out of my window, I just got one!!!
> 
> Thomas

:-)

here's mine
http://billhails.net/Gallery/Saucer.html

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

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Oddly enough, one showed up in an HDR image...

http://www.gate.net/~hobbes/UFO.jpg



Kyle

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And I was just glancing through some family shots:
http://www21.brinkster.com/jrcsurvey/skiing/index.html

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Bill Hails <bil### [at] europeyahoo-inccom> wrote:
> Not sure on policy for photo/raytrace composites, so I won't
> post the actual image here. I'm quite pleased with it though:
>
> http://billhails.net/Gallery/visitor.html
>

The message below is driving me mad. I am sure that you could post it here.
Just to let me have a look. Pretty Please :-)


Access to this web site has been blocked because it's content has been
classified as inappropriate by Rolls-Royce.

If you require access to this site please contact your IT Manager.

Stephen

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Bill Hails <bil### [at] europeyahoo-inccom> wrote:
>
> http://billhails.net/Gallery/visitor.html

Do you usually look at the floor with that telescope, or is it installed
upside-down just to match the ad in the circular? ;-)

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Stephen wrote:

> Bill Hails <bil### [at] europeyahoo-inccom> wrote:
>> Not sure on policy for photo/raytrace composites, so I won't
>> post the actual image here. I'm quite pleased with it though:
>>
>> http://billhails.net/Gallery/visitor.html
>>
> 
> The message below is driving me mad. I am sure that you could post it
> here. Just to let me have a look. Pretty Please :-)
> 
> 
> Access to this web site has been blocked because it's content has been
> classified as inappropriate by Rolls-Royce.
> 
> If you require access to this site please contact your IT Manager.
> 
> Stephen

I guess you work for Rolls Royce and you're trying to view it from work?
Maybe they've got something against my web hosts?

anyway, here 'tis

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

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Attachments:
Download 'visitor.jpg' (64 KB)

Preview of image 'visitor.jpg'

Cousin Ricky wrote:

> Bill Hails <bil### [at] europeyahoo-inccom> wrote:
>>
>> http://billhails.net/Gallery/visitor.html
> 
> Do you usually look at the floor with that telescope, or is it installed
> upside-down just to match the ad in the circular? ;-)

I guess a sensible answer is in order :-)
It's pointed at the floor so it can't be pointing at the sun.

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

Post a reply to this message

Bill Hails <me### [at] billhailsnet> wrote:
>
> I guess you work for Rolls Royce and you're trying to view it from work?
> Maybe they've got something against my web hosts?
>
> anyway, here 'tis
>

Thanks Bill now I can see what the excitement is about. It looks very good,
I hope that it (?) is house trained.
I am working at RR on a contract and two weeks ago someone attacked their
site so the shutters came down with a clang. I can’t even get my personal
email now. Which doesn’t make the job any easier as they’ve not set up my
R-R email account.

Stephen

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Bill Hails wrote:
> Not sure on policy for photo/raytrace composites, so I won't
> post the actual image here. I'm quite pleased with it though:
> 
> http://billhails.net/Gallery/visitor.html
> 

Very nice, Bill. I think it would look more "integrated" if the textures 
were less reflective, so you will see a bit of the shading of the object 
"matching" the real scene lighting.

BTW, I purchased a very good mirror ball some months ago, but I found my 
camera only has autofocus, and it refuses to focus the on reflected 
environment, so I can't get a sharp HDRI. The lighting comes out very 
nice, but the reflections are always very blurred... anyone go a trick 
for this situation? Or should I buy a camera with manual focus?

P.S.: I tried to create the HDRI also with MegaPOV HDR output, without 
having to resort to external utilities, but I'm still polishing the 
method. It uses concentric spheres for each exposure shot, and 
successive transparency with increasing ambient values, but it's 
somewhat esoteric to adjust by now.

--
Jaime

Post a reply to this message

> BTW, I purchased a very good mirror ball some months ago, but I found my
> camera only has autofocus, and it refuses to focus the on reflected
> environment, so I can't get a sharp HDRI. The lighting comes out very
> nice, but the reflections are always very blurred... anyone go a trick
> for this situation? Or should I buy a camera with manual focus?

Best to have a camera with manual focus and shutter speed ability.  (I also
use these functions often for regular photography with my camera).
Nowadays you can get digital cameras with these functions for fairly cheap.
 (Better yet you can go DSLR if you have the money...one day... one day...)

> P.S.: I tried to create the HDRI also with MegaPOV HDR output, without
> having to resort to external utilities, but I'm still polishing the
> method. It uses concentric spheres for each exposure shot, and
> successive transparency with increasing ambient values, but it's
> somewhat esoteric to adjust by now.
>
> --
> Jaime

Can you try averaging the images using a weighting appropriate to the
reltive f-stops and camera response curve?


-tgq

Post a reply to this message

Trevor G Quayle wrote:
> Best to have a camera with manual focus and shutter speed ability.
> (I also use these functions often for regular photography with my
> camera). Nowadays you can get digital cameras with these functions
> for fairly cheap. (Better yet you can go DSLR if you have the
> money...one day... one day...)

   I know very little about cameras: this is the first time I own a
camera in my life, believe it or not... the problem is that I didn't
have HDRI in mind when I purchased it, so following Murphy's law I
did chose the wrong one.

> Can you try averaging the images using a weighting appropriate to the
>  reltive f-stops and camera response curve?

   Very good suggestion, but I would have to learn *a lot* about
photography to be able to do this... Now that I remember, my brother was
into the photographic hobby some years ago and perhaps he still has some
basic books around (I only have to find the time to read them... :)

--
Jaime

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Perhaps it's just a coincidence, but some weeks ago they appeared over 
the autobahn:

Post a reply to this message

Attachments:
Download 'autobahn-060219-ufo.jpg' (91 KB)

Preview of image 'autobahn-060219-ufo.jpg'

Jaime Vives Piqueres <jai### [at] ignoranciaorg> wrote:
> > Can you try averaging the images using a weighting appropriate to the
> >  reltive f-stops and camera response curve?
>
>    Very good suggestion, but I would have to learn *a lot* about
> photography to be able to do this... Now that I remember, my brother was
> into the photographic hobby some years ago and perhaps he still has some
> basic books around (I only have to find the time to read them... :)
>
> --
> Jaime

Here is my attempt at doing this (I assume I know what you are doing, i.e.
you are trying to assemble a series of LDR images into an HDR image within
POV).  The difficult part is determining a camera response curve (similar
to monitor gamma) and the relative/absolute F-Stop values for the given
images. I'm not even sure I've applied the response curve correctly here,
but it seems ok even though the results are slightly different than that
obtained using HDRShop.

//start

#declare CamRsp=2.2;//Camera response curve
#declare NumMaps=5;

#declare
Maps=array[NumMaps][2]{{"Chateau-4","-4"},{"Chateau-2","-2"},{"Chateau+0","0"},{"Chateau+2","2"},{"Chateau+4","4"}}//{i
mage,
absolute FStop value}

#local PIMAGE = function {
  pigment{onion
    pigment_map{
    #local i=0;#while (i<NumMaps)
      [i/NumMaps     image_map {jpeg Maps[i][0] interpolate 2 map_type 1}]
      [(i+1)/NumMaps image_map {jpeg Maps[i][0] interpolate 2 map_type 1}]
    #local i=i+1;#end
    }
    phase -0.5/NumMaps
    scale<1,1,-1>*NumMaps
  }
}

#local FRd=function(x,y,z) {max(
  #local i=1;#while (i<=NumMaps)
    #local FS=val(Maps[i-1][1]);

pow(PIMAGE(i*x/sqrt(x*x+y*y+z*z),i*y/sqrt(x*x+y*y+z*z),i*z/sqrt(x*x+y*y+z*z)).red,CamRsp)/pow(2,FS),
  #local i=i+1;#end
0)}
#local FGn=function(x,y,z) {max(
  #local i=1;#while (i<=NumMaps)
    #local FS=val(Maps[i-1][1]);

pow(PIMAGE(i*x/sqrt(x*x+y*y+z*z),i*y/sqrt(x*x+y*y+z*z),i*z/sqrt(x*x+y*y+z*z)).green,CamRsp)/pow(2,FS),
  #local i=i+1;#end
0)}
#local FBl=function(x,y,z) {max(
  #local i=1;#while (i<=NumMaps)
    #local FS=val(Maps[i-1][1]);

pow(PIMAGE(i*x/sqrt(x*x+y*y+z*z),i*y/sqrt(x*x+y*y+z*z),i*z/sqrt(x*x+y*y+z*z)).blue,CamRsp)/pow(2,FS),
  #local i=i+1;#end
0)}


#declare Stops=0;

#declare Tex1=
  texture{
    pigment{average
      pigment_map{
          [function{FRd(x,y,z)/10000} color_map{[0 rgb 0][1 rgb <1,0,0>]}]
          [function{FGn(x,y,z)/10000} color_map{[0 rgb 0][1 rgb <0,1,0>]}]
          [function{FBl(x,y,z)/10000} color_map{[0 rgb 0][1 rgb <0,0,1>]}]
      }
    }
    finish {ambient 3*pow(2,Stops)*10000 diffuse 0}
  }

//

-tgq

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Jaime Vives Piqueres wrote:

> Bill Hails wrote:
>> [...]
> 
> Very nice, Bill. I think it would look more "integrated" if the textures
> were less reflective, so you will see a bit of the shading of the object
> "matching" the real scene lighting.

Yes, I'll give it a try, but the least reflective part, the wing, is
imo the least integrated-looking part of the model. I think another
part of the problem was that the HDRI was only composed of 3 images
+/- 3 stops each, not a very H DRI :-)

> BTW, I purchased a very good mirror ball some months ago, but I found my
> camera only has autofocus, and it refuses to focus the on reflected
> environment, so I can't get a sharp HDRI. The lighting comes out very
> nice, but the reflections are always very blurred... anyone go a trick
> for this situation? Or should I buy a camera with manual focus?

Yes, that would help, but autofocus can sometimes be persuaded to
focus on a reflection.

There are some nice "creative compacts" that allow manual control,
and if you want to go the distance, a digital SLR is a wonderful
thing but tbh it was my sudden discovery of photography that has
kept me away from povray for so long, and you wouldn't want that
to happen to you would you? :-)

> P.S.: I tried to create the HDRI also with MegaPOV HDR output, without
> having to resort to external utilities, but I'm still polishing the
> method. It uses concentric spheres for each exposure shot, and
> successive transparency with increasing ambient values, but it's
> somewhat esoteric to adjust by now.
> 
> --
> Jaime

I've not tried that myself.

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

Post a reply to this message

Trevor G Quayle wrote:
> Here is my attempt at doing this (I assume I know what you are doing, i.e.
> you are trying to assemble a series of LDR images into an HDR image within
> POV).  The difficult part is determining a camera response curve (similar
> to monitor gamma) and the relative/absolute F-Stop values for the given
> images. I'm not even sure I've applied the response curve correctly here,
> but it seems ok even though the results are slightly different than that
> obtained using HDRShop.

   Thanks for sharing! I didn't try to understand what you done there, 
but it gives much better results than the simple linear approach I was 
using. And it's also much more practical to have it on a single layer, 
of course. Now, if I can convince the camera to focus on the reflection...

--
Jaime

Post a reply to this message

Bill Hails wrote:
> Yes, that would help, but autofocus can sometimes be persuaded to
> focus on a reflection.

   I tried some weird tricks, but none worked... :(

> There are some nice "creative compacts" that allow manual control,
> and if you want to go the distance, a digital SLR is a wonderful
> thing but tbh it was my sudden discovery of photography that has
> kept me away from povray for so long, and you wouldn't want that
> to happen to you would you? :-)

   That can't happen to me... I'm too lazy to change now! Anyhow, I will 
not try... ;)

--
Jaime

Post a reply to this message

Jaime Vives Piqueres <jai### [at] ignoranciaorg> wrote:
> Trevor G Quayle wrote:
> > Here is my attempt at doing this (I assume I know what you are doing, i.e.
> > you are trying to assemble a series of LDR images into an HDR image within
> > POV).  The difficult part is determining a camera response curve (similar
> > to monitor gamma) and the relative/absolute F-Stop values for the given
> > images. I'm not even sure I've applied the response curve correctly here,
> > but it seems ok even though the results are slightly different than that
> > obtained using HDRShop.
>
>    Thanks for sharing! I didn't try to understand what you done there,
> but it gives much better results than the simple linear approach I was
> using. And it's also much more practical to have it on a single layer,
> of course. Now, if I can convince the camera to focus on the reflection...
>
> --
> Jaime

What I did was not too difficult.
1) First I mapped the images using the onion pattern to enable being able to
use loops to simplify the code for varying numbers of input images.
2) Then for each onion layer (representing each LDRI) convert the image
colour (for each r,g,b channel) by COL^CamRsp which converts the pixel
colour to the corresponding real world colour according to the camera
response.
3) Divide the resulting colour by 2^FStop, this coverts the colour of the
corresponding image to its equivilant at 0 stops.
4) Use the max colour found.  Any colours that were clipped in the
corresponding LDRIs (i.e. values of 0 or 1) get dropped out.  (Any colours
that were still clipped at the lowest and highest fstop values will still
be clipped however)

This is a very rough method and assumes that you know the camera response
and the FStop values of each LDRI.  Programs like HDRShop can do a much
better job of estimating these sorts of things.

There is no need to add the successive images together, (as it wouldn't give
the proper result anyways). What HDRI creation is trying to achieve, is find
the real world brightness of every pixel in the image.  If you had only one
image, but there were no clipped colours, then it could act directly like
an HDRI.  However, due to photographic and image storage restrictions,
colour do get clipped.  rgb values are limited to 1, but brightnesses of
lights tend to be much higher, especially as the FStop value gets higher,
and they get clipped to 1 in the image file.  On the other hand, dark
shadow areas can get clipped to 0 due to decimal place truncation at lower
FStop values.

So basically if you take a low FStop image and a high FStop image, convert
them to an equal FStop level, then you just need to check for the greatest
pixel valuebetween the two.  Ideally, for pixels not clipped in either
LDRI, the values should be the same.  For any pixel that was clipped in one
LDRI but not the other, the clipped one will get dropped out.  And for any
pixel clipped in both, well it'll stay clipped, as there is no easy way to
determine the actual value, there isn't enough information.

Hope this helps you understand HDRI and what I did a bit more and I didn't
bore you to death.  I don't profess to be an expert, but I have been
working with HDRI a lot lately so have had to get to understand it myself.

(FYI: in case you don't know, FStops double (or half) the light let in, so
an increase of an image of n Stops will result in an image 2^n times
brighter.)

-tgq

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High!

Bill Hails wrote:

> I guess a sensible answer is in order :-)
> It's pointed at the floor so it can't be pointing at the sun.

As an amateur stargazer myself, I would like to ask what aperture do you 
have there - seems to me it's a 6-incher, isn't it?

See you in Khyberspace!

Yadgar

Now playing: El Greco, Movement 2 (Vangelis)

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Sorry, Jörg, I've been away for a few days.

Jörg 'Yadgar' Bleimann wrote:

> High!
> 
> Bill Hails wrote:
> 
>> I guess a sensible answer is in order :-)
>> It's pointed at the floor so it can't be pointing at the sun.
> 
> As an amateur stargazer myself, I would like to ask what aperture do you
> have there - seems to me it's a 6-incher, isn't it?

11cm Russian-made TAL-1, I can see the rings of Saturn on a clear night :-)

> See you in Khyberspace!
> 
> Yadgar
> 
> Now playing: El Greco, Movement 2 (Vangelis)

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

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High!

Bill Hails wrote:

> 11cm Russian-made TAL-1, I can see the rings of Saturn on a clear night :-)

Ah, the TAL-1! The mounting looks quite massive, it surely would carry 
an additional camera... unlike my somewhat flimsy EQ-2 with my Bresser 
Mizar (11.4 cm/900 mm focal length). Saturn's rings are generally no 
problem, I even was able to spot Titan one night... but as I until 
recently had to watch under a metropolitan area sky, this is far from 
the best results possible with a 4.5-incher - under optimal conditions 
(Afghan mountain desert sky with no scattered artificial light within a 
200-km radius) at least Rhea, Iapetus, Dione and Tethys, perhaps even 
Enceladus would be also visible...

Yes, astronomy (as well as programming) is one of the best excuses to 
turn night into day! Unfortunately, my telescope now is with my parents 
in the dark but remote countryside, about 60 kms from here, so that I'm 
able to observe only on weekends - and during recent months, the weekend 
weather over Germany was a complete failure, just LRCC (Lower Rhenanian 
Cloud Cover)...

See you in Khyberspace!

Yadgar

Now playing: Esthematique (Serge Blenner)

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"Bill Hails" <me### [at] billhailsnet> wrote in message 
news:444537fb@news.povray.org...


> anyway, here 'tis

    Darnit! I thought the telescope was a model too!!  ;)


    Nice telescope Bill. Must get one sometime.


      ~Steve~

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

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