POV-Ray : Newsgroups : povray.pov4.discussion.general : Wood pattern and v4.0. : Re: Wood pattern and v4.0. Server Time
9 Dec 2023 09:17:02 EST (-0500)
  Re: Wood pattern and v4.0.  
From: William F Pokorny
Date: 15 Sep 2023 21:34:32
Message: <65050628@news.povray.org>
On 9/15/23 07:10, And wrote:
> I haven't used povr yet.
> I found that your image (top row) are similar to the deform of the IsoWood
> include files of Christoph Hormann.
> The bottom row is interesting, too.

I played a little with the IsoWood macros a 'long' time ago and have a 
copy somewhere, but I don't recall what pattern / functions were used 
for the wood patterning - thanks for the info on the look of it in 

I've been following your 'wood work' programming effort. I confess to 
more or less thrashing around, pushing here and there, on what can be 
done and only sometimes with 'wood' grain specifically in mind.

Yes, the approach in the bottom row is to start with an internal 
turbulence scaled small to make the rings just a little bit noisy as 
they go around - and then on top of that to layer one or more additional 
warp turbulences at larger scales to get a more complete wood pattern look.

This turbulence layering approach is difficult with the old style 'wood' 
because it has those fixed, positional harmonics. It's too easy to push 
the 'favorable' portion of the pattern off of the surface being textured.

I'm starting to look now at pushing into the warp{} mechanisms with 
thoughts toward a re-work of the underlying functionality of that code. 
In the povr fork, I have quite a few fixes and additions hacked into 
that code over what is in official POV-Ray releases, but it's all 
'hacked in'. I'd like to refined what's there into something better.

Anyhow... I'll attach another image using the povr updated 'wood' as the 
base pattern - not really aimed to be anything in particular. It's a 
test image for other features as much as the changed 'wood', but I think 
it looks interesting.

Using it_* turbulence and warp{it_* ...} turbulence with emitting, 

Oh, the containing shape is an isosurface based upon povr's inbuilt 
f_toupie() function. Here with options forming a shape somewhat like a 
spinning top. It's thicker in the middle, thinning as it moves out from 
the center before thickening into an outer torus at the edges.

Bill P.

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