Looks nice!
The gate needs hinges though.

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Kirk Andrews wrote:

>> Nice gate design - how'd you do it?
>> --
>> Stefan
> 
> Thanks!
> 
> Perhaps there is a better way to do it, but I first designed it in a
> vector-editor, and then exported it as a bitmap image.  In POV I turned
> the bitmap into a function, and used the function in an isosurface. The
> bumps were added by subtracting a pigment function in the isosurface.


Yikes! How do you "turn a bitmap into a function"? The isosurface part I
(think) I've got an idea how to do, as well as adding the bumps. But how do
you turn a bitmap into an isosurface function?

Regards,
-- 
Stefan

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> Yikes! How do you "turn a bitmap into a function"? The isosurface part I
> (think) I've got an idea how to do, as well as adding the bumps. But how do
> you turn a bitmap into an isosurface function?

You can turn any pigment into a function, so first declare an image pattern
pigment, and then declare a function using that pigment.  This is my code:

#declare PGate =
pigment {
  image_pattern {
    jpeg "Gate/GateStructure4.jpg"   // image file to read
  }
}

#declare GateF =
function {
  pigment {PGate scale 10000*z}
}

You'll need a fairly high max_gradient setting (like 35) for it to come out
right.

-- Kirk

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Attachments:
Download 'gatestructure4.jpg' (18 KB)

Preview of image 'gatestructure4.jpg'

"s.day" <s.d### [at] uelacuk> wrote:
> This is looking really good. The isosurface rocks in the foreground look a
> bit smooth for rocks (I mean at a fine detail level if this makes any
> sense), is this just a low quality accuracy setting? What method/patterns
> did you use to make the rock isosurface? I have always found combining
> wrinkles with other patterns good for a rock surface.

Thanks!  I wanted a wanted the rocks to look dry and weathered, so I wanted
them a little smoothe.  For these I just used a bumps pigment with
turbulence -- adding a wrinkles pigment probably would have added some
detail, though.


> I look forward to seeing the next version of this image, what are the render
> times like..
>
> Sean

It took about 4.5 hours on my 2 GHz machine.

-- Kirk

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"fls13" <fls### [at] netzeronet> wrote:
> One of the finest Povray renders I've seen.

Thank you!  A very flattering compliment indeed!

> How about seeing your light and radiosity settings?

light_source {  //Sunlight
  <0, 0, 0>            // light's position (translated below)
  color rgb <1.5, 1.3, .4>*3.25  // light's color
  translate <-20, 20,  30>*1000
}

global_settings {
  radiosity {
    pretrace_start 0.08           // start pretrace at this size
    pretrace_end   0.04           // end pretrace at this size
    count 50                      // higher -> higher quality (1..1600) [35]
    nearest_count 5               // higher -> higher quality (1..10) [5]
    error_bound 0.5               // higher -> smoother, less accurate [1.8]
    recursion_limit 1             // how much interreflections are
calculated
    low_error_factor .5           // reduce error_bound during last pretrace
    gray_threshold 0.0            // increase for weakening colors (0..1)
[0]
    minimum_reuse 0.015           // reuse of old radiosity samples [0.015]
    brightness .5                  // brightness of radiosity effects (0..1)
[1]
    adc_bailout 0.01/2
    save_file "InvitationRadiosity"       // save radiosity data
  }
}

  light_source {  //Reddish foreground light
    <0, 0, 0>            // light's position (translated below)
    color rgb <.5, .2, .2>*.1  // light's color
    translate < 20,  50, -30>
    fade_distance 150
    fade_power 2
    shadowless
  }

--  Kirk

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"Tim Attwood" <tim### [at] comcastnet> wrote:
> Looks nice!
> The gate needs hinges though.

Goodness, you're right!  Not only are they unlocked, they don't even have
hinges!  I'll have to fix that.

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Kirk Andrews wrote:

>> Yikes! How do you "turn a bitmap into a function"? The isosurface part I
>> (think) I've got an idea how to do, as well as adding the bumps. But how
>> do you turn a bitmap into an isosurface function?
> 
> You can turn any pigment into a function, so first declare an image
> pattern pigment, and then declare a function using that pigment.  This is
> my code:

Ooooo! Thanks Kirk - I'd never have thought of that myself. Of course, it
probably is there in the docs, but I'd -never- have figured it out / picked
it up myself.

I've just had an epiphany here - you've opened up so many cool ideas my head
is spinning... thanks for sharing the code. You've just stimulated some
serious creativity - this technique offers so many possibilities (for me at
least.)

Thanks again...

Regards,
-- 
Stefan

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Great job with the scene, both the architectual and the environmental.
The style appeals to me very, very much!

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"Kirk Andrews" <kir### [at] hotmailcom> wrote:

> You can turn any pigment into a function, so first declare an image pattern
> pigment, and then declare a function using that pigment.  This is my code:
>
> #declare PGate =
> pigment {
>   image_pattern {
>     jpeg "Gate/GateStructure4.jpg"   // image file to read
>   }
> }
>
> #declare GateF =
> function {
>   pigment {PGate scale 10000*z}
> }


Kirk,

It appears that I need a little help on your "image as function" code.  If I
try to render the object (see below) POVray tells me this:

{
 function
 {
  GateF(x,y,z)
 }
Parse Error: Expected '.', } found instead

Did I misunderstand your sample?

-Allan



Here is my code...

#declare PGate =
pigment
{
  image_pattern
  {
    jpeg "GateStructure4.jpg"   // image file to read
  }
}

#declare GateF = function {pigment {PGate scale 10000*z}}

isosurface
{
  function
  {
    GateF(x,y,z)
  }
  accuracy 0.01
  threshold 1.0
  contained_by {box {-2,2}}
  max_gradient 35
  uv_mapping
  material
  {
    texture
    {
      pigment {color rgb <0.98, 0.83, 0.58>}
      normal
      {
        brick 0.5 //amount
      }
      finish
      {
        diffuse 0.6
        brilliance 1.0
      }
    }
    interior
    {
      ior 1.3
    }
  }
}

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> Kirk,
>
> It appears that I need a little help on your "image as function" code.  If I
> try to render the object (see below) POVray tells me this:
>
> {
>  function
>  {
>   GateF(x,y,z)
>  }
> Parse Error: Expected '.', } found instead
>
> Did I misunderstand your sample?
>
> -Allan

Pov is looking for "function {GateF(x,y,z).gray}"  It will always require
..gray or .red etc. if you are using a pigment function (including a
bitmap).

Here's my whole code for the gate:


#declare PGate =  //The bitmap pigment
pigment {
  image_pattern {
    jpeg "Gate/GateStructure4.jpg"
  }
}

#declare GateF =  //convert to function
function {
  pigment {PGate scale 10000*z}
}

#declare Gbumps =  //bumps applied
function {
  pigment {
    bumps
    scale .01
    color_map {
      [0 rgb 0]
      [1 rgb 1]
    }
  }
}

#declare GPlaneF =  //the pigment function is infinite in the z direction.
This limits it and allows for some rounding of the edges when combined with
the bumps pigment
function {
  pigment {
    gradient z
    color_map {
      [0.0 rgb 0]
      [0.1 rgb 1]
      [0.9 rgb 1]
      [1.0 rgb 0]
    }
    scale .1*z
  }
}

#declare IsoGate =
isosurface {
  function {(GateF(x,y,0).gray -.5 +
Gbumps(x,y,z).gray*.5)*GPlaneF(x,y,z).gray}
  contained_by { box { 0, <1,.999,.05> } }
  accuracy 0.001
  max_gradient 35
  scale 2*y
  translate -1*x
  translate 1*x
}

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