POV-Ray : Newsgroups : povray.bugreports : alpha.10064268 freezes : Re: alpha.10064268 freezes Server Time
25 Oct 2021 02:17:54 EDT (-0400)
  Re: alpha.10064268 freezes  
From: William F Pokorny
Date: 19 Mar 2020 09:01:55
Message: <5e736d43$1@news.povray.org>
On 12/9/19 5:03 PM, jr wrote:
...
Apparently I started a response months back and didn't finish it. 
(Thunderbird was not showing anything sitting in my drafts folder.)

Up front. I'm changing direction. I'm working toward a personal, 
substantially cut down, *nix only version of POV-Ray. With new git (or 
perhaps mercurial) repositories once I get done with all the pruning. 
Meaning, while the branches I've posted are today still pull-able 
against the last commit to master more than a year ago, I no longer plan 
to update/re-base those branches should POV-Ray development resume.

-----
Now, completing the response to your months old questions:

> 
> slightly confused by the interpolation options, they're not "regular" POV-Ray?
Yes and no.

In my 'Density File Pattern Updates' branch interpolation 0 is the only 
option which remains untouched(a). Interpolations 1 & 2 work the same 
except the voxel half offset is fixed - voxels values are centered as 
they always should have been (Christoph asked me to add options 11 & 12 
IIRC which work with the half voxel offsets/overruns as before or like 1 
& 2 today, so there was a path for folks to duplicate the incorrect 
behavior for replication of old scenes).

(a) - Lying. There is a somewhat substantial performance improvement 
achieved by avoiding duplicate work.

There are new interpolations 3,4,5 which use a kind of exponential 
blobbing and aimed mostly at creating base isosurface functions/shapes 
though, of course, they can be used as patterns too.

There are some new pattern value generation helper interpolations in 9 & 
10 which look for the nearest non-zero, '0' interpolation which can then 
be used for complex patterning on shapes. This relates to general 
efforts. I've been attempting to come up with better ways to texture 
which allowing a larger set of pattern and shape modifiers. Warp{} the 
isosurface (or collection of placed objects) and use the same warp for 
the shape's texturing. I've posted examples of this a few times.

Interpolations 9 & 10 are basically exploring the idea of painting 
shapes with DF3s - using DF3 files as a texture mapping method.

Aside: Today interpolations 1 & 2 have seam and ringing artefacts, 
respectively, limiting their usefulness as functions / shapes. The same 
sort of problem we have today in v3.8 with the new blob potential 
pattern use - because blob shapes themselves have continuity issues when 
actually blobbing.

...
> 
> after some thought, the 'Density File Pattern Updates' + 'Non-portable 32 bit
> DF3 write capability' + perhaps 'Both image_map and pigment_map support in
> density block'.  would that combination "play nice"?
> 
Yes, should be you can use all those at once. I've made an effort to 
keep the branches independent even changing a couple slightly in the 
interim so they don't collide(1,2).

(1) - Single branches are tested alone. For multiple pulls, I test this 
only in the order of pulls I use to build my 'povr' version. So, there 
is a chance when pulling multiple branches I missed some detail where 
order matters.

(2) - I did a lot of work in the solver branch to standardize / cleanup 
epsilons and other 'magic' values which were all over the place in use 
and effectiveness. Thus far I've not used those fixes in other branches 
- though it's gotten harder and harder not to do this. The wave modifier 
/ pattern / function cleanup I've been working on need the better set 
'epsilon-like' values too.

>> ...
>> Once personal wiki's are up. They are sitting out there not very
>> visible. Is there even a page which lists user wikis?
> 
> know what you mean.  although they all have "sitemap"s, few provide table of
> contents.  (self-defeating, imo)
> 
Yep, agree.

> 
>> ...
>> With user wikis there is always the problem that we might not completely
>> understand what we are trying to document ;-). What to do when well
>> intention-ed, but wrong pages get posted?
> 
> isn't that what the "discussion" page is there for?
> 
> inadvertent errors would be corrected, I'm (fairly) sure.
> 
Yes, ideally.

> 
>> ...
>> We have a single physical web site. When it goes down or my local
>> network connection does, I'd like to have local copy of the wiki,
>> library and the newsgroup postings as I do for the documentation. Or at
>> least have snapshots of these available on the cloud - github or
>> wherever.
>> A few expert folk maintain their own web sites for what might go on a
>> wiki, but that an investment. Plus, knowing where all these web sites
>> are today means maintaining a list of links to them yourself.
> 
> it would be nice to have mirror or two.  (personally, I think that if "the gods"
> put the content on a DVD (or two) and offered those for sale, I'd buy.  and
> while on money, if I could take out an annual subscription of 10-15 € or USD to
> help maintain .. POV-Ray, I would.  (and am quite certain that I'm not alone in
> that))
>
Christoph had button up at one point (for uberpov only?), but it was to 
some new-ish site and I'm leery of those. I'd subscribe too to support 
POV-Ray - if the payment mechanism reputable.

Have you seen where github itself is pushing / supporting better ways to 
financially support open source projects (GitHub sponsors)? For example:

https://www.youtube.com/watch?v=FYkBA9epUEk

and

https://www.youtube.com/watch?v=e_zhHQXTwVo

and

https://help.github.com/en/github/administering-a-repository/displaying-a-sponsor-button-in-your-repository

I've watched a few of the videos and they're good in pointing out that, 
in other than single developer projects, support means more than just 
gathering money. It means establishing and maintaining a governing group 
deciding direction / how to spend. Otherwise you can end up with a pile 
of money and no idea/mechanism for how to spend it...

I'd pay for a web-news group database searchable dump too (perhaps USB 
over DVD... :-) ) - the news server representation is only correct for 
the more current posts (last 10 years or so). Searches done via 
thunderbird don't turn up - say pre 2007 stuff - though how far back it 
works depends some on the group. If you know it's an old topic, the web 
search is the only way to go - but a few times now I've struggled 
finding what I want with this google based method.

Aside: Chris taught me individual groups can be searched via google with 
arguments:

site:news.povray.org/povray.bugreports/ freezes

but that doesn't turn up anything, where say:

site:news.povray.org/povray.bugreports/ crash

does. Not dug much, but it seems like the google indexing is perhaps 
done only once in a while - like it's lagging substantially (a year?). 
Don't know. The by group method is useful, but I find myself not 
counting on the google search completely either at this point.

Anyway... Having a paid support mechanism / data-products of some kind 
or not, would be up to the core team / Chris I'd guess.

------------

FYI. I captured your February dictionary parsing bug test case for my 
own use - thanks. No idea if/when I might get to looking at it, but it's 
now one of my parser test cases.

My apologies for the SLOW response.

Bill P.


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