POV-Ray : Newsgroups : povray.general : A little help about old vers. Server Time
18 Jun 2025 16:02:22 EDT (-0400)
  A little help about old vers. (Message 85 to 87 of 87)  
<<< Previous 10 Messages Goto Initial 10 Messages
From: GioSeregni
Subject: Re: A little help about old vers.
Date: 18 Jun 2025 08:45:00
Message: <web.6852b4b7ce24a8bbeeec206c59126100@news.povray.org>
"Maetes" <nomail@nomail> wrote:
> I worked on your scripts yesterday and I have to say, Dennis looks really cool.
>
> In the Inc file of Bike and Audi it is quite messy, but I separated and cleaned
> up Bike, Audi maybe today.
> The BMW also looks good, I'll get to work on it right away.
>
> I'll post the scripts I've changed as soon as they are presentable, until then
> greetings from Dennis :)
>
> And from me, of course.
> Ma

Nice job!
Be careful, because Dennis was wandering around the web, I just captured him,
cleaned him, colored him, meshed him, and...
imported into our PovRay world!
thanks also to the unknown author!

PS.
I wrote that I can't post my executable for transformations here. I don't want
to post exe that often (always) worry with false positives of the antivirus.

But scripts and plugins written in plain text are not a concern, so I thought
I'd make a new topic in the next few days with two plugins for SketcUp.
- Import STL
- Export POV and/or inc.
I think they could be useful.
They are made for SketchUp 8 and SketchUp Make 2017.
In SketchUp you can give truecolor colors and transparencies that will then also
be acquired by PovRay.
The latest FREE versions (8 and Make 2017) that you can find on the web.
The most recent ones are paid and I haven't tested them.
So stay online ... if you're interested
BR
G.


Post a reply to this message

From: Bald Eagle
Subject: Re: A little help about old vers.
Date: 18 Jun 2025 09:35:00
Message: <web.6852c07bce24a8bbd0f21c5825979125@news.povray.org>
"GioSeregni" <gms### [at] hotmailcom> wrote:

> General algorithms are no good in my opinion.
> They are recursive and have unintelligent ways.
> They consume memory.
> They exaggerate in the points that are already rich and perhaps are deficient in
> the points that need it most.

What you could do is test the distance between points, and points that are far
apart can get refined, and points that are close together can get skipped.

However, I'd suggest making it more sophisticated than that - test the curvature
along some distance on the surface.  Flat areas get skipped, and highly curved
areas get refined.   Find some way to appropriately weight the curvature vs
distance metrics.

Unnecessarily subdivided flat faces could be simplified into a single quad.

Not easy work - very tedious.  But well commented code and a flowchart of the
logic would help in future development.

- BE


Post a reply to this message

From: GioSeregni
Subject: Re: A little help about old vers.
Date: 18 Jun 2025 12:10:00
Message: <web.6852e454ce24a8bbeeec206c59126100@news.povray.org>
"Bald Eagle" <cre### [at] netscapenet> wrote:
> "GioSeregni" <gms### [at] hotmailcom> wrote:
>
> > General algorithms are no good in my opinion.
> > They are recursive and have unintelligent ways.
> > They consume memory.
> > They exaggerate in the points that are already rich and perhaps are deficient in
> > the points that need it most.
>
> What you could do is test the distance between points, and points that are far
> apart can get refined, and points that are close together can get skipped.
>
> However, I'd suggest making it more sophisticated than that - test the curvature
> along some distance on the surface.  Flat areas get skipped, and highly curved
> areas get refined.   Find some way to appropriately weight the curvature vs
> distance metrics.
>
> Unnecessarily subdivided flat faces could be simplified into a single quad.
>
> Not easy work - very tedious.  But well commented code and a flowchart of the
> logic would help in future development.
>
> - BE

You're right, but my goal is more modest. I would leave the rendering engine the
option to adapt the quality to the distance.
Second Life did it many years ago, and I think that more or less all 3D
rendering programs do it.
I don't actually know, in advance, when I create an object for my library, at
what distance it will be seen. I use the library to obtain landscape contexts
where things are as light as possible.
We got into this discussion because jr, rightly, about the BMW, said that
certain parts were too simplified. Even with the smoothing of the triangles. For
this reason, for me it is important to be able to keep the weight of the object
light, but also to have a tool for fine-tuning the critical points.
Implementing mesh enrichment is a good starting point in my opinion. If I want,
when well tested, I could also make it recursive on the entire model.
But it must generate the model. The method we saw is more of a feature of the
render engine, it is volatile. In my opinion it should be addressed at the pov
ray engine level... like "remeshing <SplitValue, WPdistance, etc etc> "


Post a reply to this message

<<< Previous 10 Messages Goto Initial 10 Messages

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.