"Mr" <m******r******at_hotmail_dot_fr> wrote:
> "Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> > The attached image is the results of my attempts to find out how Tek made the
> > images he posted in this thread:
> >
> > From: Tek
> > Subject: Isosurface City revistied (WIP-maybe)
> > Date: 2008-03-25 19:24:01
> >
https://news.povray.org/povray.binaries.images/thread/%3C47e997a1%40news.povray.org%3E/
> >
> > AFAIK he did not post the code anywhere in here - and his web pages seems to be
> > down.
> >
> > I've not yet figured out what pattern he used to make the windows.
> >
> > --
> > Tor Olav
> > http://subcube.com
> > https://github.com/t-o-k
>
> This looks close, but increasing the relative height of buildings compared to
> their base areas gave them more orthogonal / artificial looking overall lines.

I'm struggling a bit to compare the height to base ratio of buildings in
Tek's an my renders.

I'll decrease the building heights in future renders.


> by the looks of it I'm assuming that the core of your procedural is a Crackle
> pattern... If so, did you use metric 4 to give it more square appearance ?

Yes, it's a crackle pattern, but with metric 1, as Tek mentioned,

For the buildings I'm using form <-1, 0, +1> and for the ground I'm using
form <-1, +1, 0>.


> metric superior to 25 would end up providing even "squarer" angled cells.
>
> Using two planimetric components of the vector "form <x,y,z>" (depending on the
> orientation of your scene) may also allow you to control the convexity of cells.

This sounds interesting. I did not know that it was possible to make the
crackle cells more "squarer".

I know very little about crackle patterns. I tried to read about crackle
in the POV-Ray documentation, but the explanation of the parameters where
to cryptic for me.

I'll experiment with those metric values.


> Thanks for your endeavour !

No problem. It's an interesting challenge to try to find out how Tek might
have made his latest city images.


> These are base on old tweaks I had tried when comparing Blender internal Voronoi
> with pov's crackle procedural textures for the purpose of Blender to POV export.
> (draft notes attached)

Thank you. I'll have a look at your notes.

I remember now that I once read a little about Voronoi diagrams and that
they are related to crackle patterns.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k

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