Some time ago and entirely by chance, I came across this site/image: 
https://www.printables.com/model/431413-illusion-cube

I thought this was an interesting shape and I built my own version in 
POV-Ray code:

//==========================================================
#declare BaseBox =
box {
   <-1.00, -1.00, -1.00>,< 1.00, 1.00, 1.00>
}

#declare InsideHollow =
union {
   box {< 0.00, -0.899, -0.70>,< 1.01, 0.70, 0.899>}//+x
   box {<-1.01, -0.70, -0.899>,< 0.00, 0.899, 0.70>}//-x

   box {<-0.70, -0.70,  0.00>,< 0.899, 0.899, 1.01>}//+z
   box {<-0.899, -0.899, -1.01>,< 0.70, 0.70, 0.00>}//-z

   box {<-0.899,  0.00, -0.70>,< 0.70, 1.01, 0.899>}//+y
   box {<-0.70, -1.01, -0.899>,< 0.899, 0.00, 0.70>}//-y

   box {<-0.90, -0.90, -0.90>,< 0.90, 0.90, 0.90> }
}

#declare EdgeHollow = box {<-1.01, -0.2, -0.2>,< 1.01, 0.2, 0.2>}

#declare EdgeHollowsTop =
union {
   object {EdgeHollow translate <0.00, 1.00,-1.00>}
   object {EdgeHollow rotate 90*y translate < 1.00, 1.00, 0.00>}
}

#declare EdgeHollowsBase =
union {
   object {EdgeHollow translate <0.00, -1.00, 1.00>}
   object {EdgeHollow rotate 90*y translate <-1.00, -1.00, 0.00>}
}

#declare EdgeHollowsSides =
union {
   object {EdgeHollow rotate 90*z translate <-1.00, 0.00, 1.00>}
   object {EdgeHollow rotate 90*z translate <1.00, 0.00,-1.00>}
}

#declare IllusionBox =
difference {
   object {BaseBox}
   object {InsideHollow /*pigment {rgb <0,1,0>}*/}
   object {EdgeHollowsTop /*pigment {rgb <1,0,0>}*/}
   object {EdgeHollowsBase /*pigment {rgb <1,0,0>}*/}
   object {EdgeHollowsSides /*pigment {rgb <1,0,0>}*/}

   pigment {rgb 0.9}
}

object {IllusionBox}
//==========================================================

Adding a spaceship I built years ago using Silo, and a media (portal?) I 
composed the present scene.

-- 
Thomas

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Attachments:
Download 'tdg_illusion box_final.jpg' (213 KB)

Preview of image 'tdg_illusion box_final.jpg'

On 2023-07-29 08:34 (-4), Thomas de Groot wrote:
> [snip]
> 
> Adding a spaceship I built years ago using Silo, and a media (portal?) I
> composed the present scene.

That's a nice star field!  It looks more convincing than most CGI star
fields I've seen for which diffraction spikes were attempted.

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hi,

Thomas de Groot <tho### [at] degrootorg> wrote:
> Some time ago and entirely by chance, I came across this site/image:
> ...
> I thought this was an interesting shape and I built my own version in
> POV-Ray code:

thanks, hope to look at this closer soon-ish.

(wondering if it could be drawn with a 3D L-system ? :-))


> Adding a spaceship I built years ago using Silo, and a media (portal?) I
> composed the present scene.

don't know much about spaceships (or star fields :-)), but the scene has that
"Twilight Zone" kind of feel.  very pleasing.


regards, jr.

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Thomas de Groot <tho### [at] degrootorg> wrote:
> Some time ago and entirely by chance, I came across this site/image:
> https://www.printables.com/model/431413-illusion-cube
>
> I thought this was an interesting shape and I built my own version in
> POV-Ray code:
>
> //==========================================================
> #declare BaseBox =
> box {
>    <-1.00, -1.00, -1.00>,< 1.00, 1.00, 1.00>
> }
>
> #declare InsideHollow =
> union {
>    box {< 0.00, -0.899, -0.70>,< 1.01, 0.70, 0.899>}//+x
>    box {<-1.01, -0.70, -0.899>,< 0.00, 0.899, 0.70>}//-x
>
>    box {<-0.70, -0.70,  0.00>,< 0.899, 0.899, 1.01>}//+z
>    box {<-0.899, -0.899, -1.01>,< 0.70, 0.70, 0.00>}//-z
>
>    box {<-0.899,  0.00, -0.70>,< 0.70, 1.01, 0.899>}//+y
>    box {<-0.70, -1.01, -0.899>,< 0.899, 0.00, 0.70>}//-y
>
>    box {<-0.90, -0.90, -0.90>,< 0.90, 0.90, 0.90> }
> }
>
> #declare EdgeHollow = box {<-1.01, -0.2, -0.2>,< 1.01, 0.2, 0.2>}
>
> #declare EdgeHollowsTop =
> union {
>    object {EdgeHollow translate <0.00, 1.00,-1.00>}
>    object {EdgeHollow rotate 90*y translate < 1.00, 1.00, 0.00>}
> }
>
> #declare EdgeHollowsBase =
> union {
>    object {EdgeHollow translate <0.00, -1.00, 1.00>}
>    object {EdgeHollow rotate 90*y translate <-1.00, -1.00, 0.00>}
> }
>
> #declare EdgeHollowsSides =
> union {
>    object {EdgeHollow rotate 90*z translate <-1.00, 0.00, 1.00>}
>    object {EdgeHollow rotate 90*z translate <1.00, 0.00,-1.00>}
> }
>
> #declare IllusionBox =
> difference {
>    object {BaseBox}
>    object {InsideHollow /*pigment {rgb <0,1,0>}*/}
>    object {EdgeHollowsTop /*pigment {rgb <1,0,0>}*/}
>    object {EdgeHollowsBase /*pigment {rgb <1,0,0>}*/}
>    object {EdgeHollowsSides /*pigment {rgb <1,0,0>}*/}
>
>    pigment {rgb 0.9}
> }
>
> object {IllusionBox}
> //==========================================================
>
> Adding a spaceship I built years ago using Silo, and a media (portal?) I
> composed the present scene.
>
> --
> Thomas

Very cool. Love the look.
Miller

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Op 29-7-2023 om 19:31 schreef Cousin Ricky:
> On 2023-07-29 08:34 (-4), Thomas de Groot wrote:
>> [snip]
>>
>> Adding a spaceship I built years ago using Silo, and a media (portal?) I
>> composed the present scene.
> 
> That's a nice star field!  It looks more convincing than most CGI star
> fields I've seen for which diffraction spikes were attempted.
> 

Thanks. The star field is Milkyway_BG.exr which I found a year ago... 
somewhere. Typically, I failed to note its exact origin :-(

I have not used it much yet but I also like it.

-- 
Thomas

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Op 29-7-2023 om 20:56 schreef jr:
> hi,
> 
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> Some time ago and entirely by chance, I came across this site/image:
>> ...
>> I thought this was an interesting shape and I built my own version in
>> POV-Ray code:
> 
> thanks, hope to look at this closer soon-ish.
> 
> (wondering if it could be drawn with a 3D L-system ? :-))
> 
Ha! Who knows? I'll leave that to the L-system gang which is haunting 
these ng's lately... ;-)

> 
>> Adding a spaceship I built years ago using Silo, and a media (portal?) I
>> composed the present scene.
> 
> don't know much about spaceships (or star fields :-)), but the scene has that
> "Twilight Zone" kind of feel.  very pleasing.
> 
Thanks, jr. I didn't think about the "Twilight Zone" when I worked on 
this, but I agree.

-- 
Thomas

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Op 30-7-2023 om 03:17 schreef Mike Miller:
> Very cool. Love the look.
> Miller
> 
Thanks Mike

-- 
Thomas

Post a reply to this message

Thomas de Groot <tho### [at] degrootorg> wrote:
> Some time ago and entirely by chance, I came across this site/image:
> https://www.printables.com/model/431413-illusion-cube
>
> I thought this was an interesting shape and I built my own version in
> POV-Ray code:

Nice.  :)

I would have been tempted to do it as a union, probably trying to be (too)
clever and using some kind of algorithm to use +/- <x, y, z>, etc.

It _does_ kind of scream ... 3D L-system, now doesn't it?   :D

This IS very well done - it has a very nice overall space fields, where all of
the elements come together and blend into a nicely composed space scene.

- BW

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Op 30-7-2023 om 13:40 schreef Bald Eagle:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> Some time ago and entirely by chance, I came across this site/image:
>> https://www.printables.com/model/431413-illusion-cube
>>
>> I thought this was an interesting shape and I built my own version in
>> POV-Ray code:
> 
> Nice.  :)
> 
> I would have been tempted to do it as a union, probably trying to be (too)
> clever and using some kind of algorithm to use +/- <x, y, z>, etc.
> 
Oh, I am sure there are better ways; I just did a quick-and-dirty 
modelling without thinking too deeply about other options. ;-)

> It _does_ kind of scream ... 3D L-system, now doesn't it?   :D
> 
Now, you are the second one here to mention that. I have not paid much 
attention to the L_system discussion here however.

> This IS very well done - it has a very nice overall space fields, where all of
> the elements come together and blend into a nicely composed space scene.
> 
Thanks indeed. It was a good occasion to use that Milkyway star field 
together with my old spaceship. Always nice dig into the old dusty 
coffers with discarded and forgotten models... :-)

-- 
Thomas

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

>
> Adding a spaceship I built years ago using Silo, and a media (portal?) I
> composed the present scene.
>

Hi,

that's a wonderful piece of art.
(Might be interesting to test it with Chris Colefax' Galaxy plugin.)

It reminds me of a SciFi series called 'Andromeda' and there it was a portal to
a different universe.

And yes, it's a form of a Hilbert curve and it was used as logo for SGI.

Cheers, Droj
(one of the Lsystem gang)

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Attachments:
Download 'ls_hilb_0a.png' (320 KB)

Preview of image 'ls_hilb_0a.png'