POV-Ray : Newsgroups : povray.general : Smooth triangles tutorials/tools? Server Time: 26 Jan 2021 02:38:08 GMT
 Smooth triangles tutorials/tools? (Message 1 to 2 of 2)
 From: JÃ¶rg "Yadgar" Bleimann Subject: Smooth triangles tutorials/tools? Date: 1 Feb 2020 17:54:37 Message: <5e35bb5d\$1@news.povray.org>
```Hi(gh)!

To get rid of pixel artifacts when rendering Earth surface reliefs
(mesh2 objects, not heightfields!) from topographic data, I tried smooth
triangles... but as Melody's normal vector generator run abysmally slow
(200 days for just one 3601 by 3601 data points tile!), I'm looking for
a good introduction into smooth triangle normal calculation (the
official 3.7 tutorials says nothing about it) - or at least a tool which
does the math for me!

See you in Khyberspace!

```
 From: Bald Eagle Subject: Re: Smooth triangles tutorials/tools? Date: 1 Feb 2020 19:40:00 Message:
```=?UTF-8?Q?J=c3=b6rg_=22Yadgar=22_Bleimann?= <yaz### [at] gmxde> wrote:
> Hi(gh)!
>
> To get rid of pixel artifacts when rendering Earth surface reliefs
> (mesh2 objects, not heightfields!) from topographic data, I tried smooth
> triangles... but as Melody's normal vector generator run abysmally slow
> (200 days for just one 3601 by 3601 data points tile!), I'm looking for
> a good introduction into smooth triangle normal calculation (the
> official 3.7 tutorials says nothing about it) - or at least a tool which
> does the math for me!
>
> See you in Khyberspace!
>

From:  http://www.povray.org/documentation/view/3.6.1/295/

"...the corners are defined as in regular triangles and <Normal_n> is a vector
describing the direction of the surface normal at each corner.

These normal vectors are prohibitively difficult to compute by hand. Therefore
smooth triangles are almost always generated by utility programs. "

So, my first intuition is to just calculate the _surface_ / face normal vector
of the regular flat triangles, and average those normals to assign to the common
vertex.

Second, I'm not saying that this has _anything_ to do with what we're talking
about here, but it "rang a bell" and seemed superficially related: