POV-Ray : Newsgroups : povray.general : Smooth level for smooth_triangle. : Re: Smooth level for smooth_triangle. Server Time
3 Mar 2024 08:01:20 EST (-0500)
  Re: Smooth level for smooth_triangle.  
From: GioSeregni
Date: 25 Nov 2023 13:45:00
Message: <web.6562405284c692a3276109cb59126100@news.povray.org>
Alain Martel <kua### [at] videotronca> wrote:

> > "GioSeregni" <gms### [at] hotmailcom> wrote:
> >> "Kenneth" <kdw### [at] gmailcom> wrote:
> >>> "GioSeregni" <gms### [at] hotmailcom> wrote:
> >>>> "Bald Eagle" <cre### [at] netscapenet> wrote:
> >>>>>
> >>>>> And if you DO see red there, then try moving the camera around, and viewing it
> >>>>> from different angles - because it may just disappear and pop up in different
> >>>>> areas.
> >>>>
> >>>> It seems that they always arise on the
> >>>> perimeter of the volumes (in positions tangential to the cone of vision)...
> >>>
> >>> Yes, that is where those artifacts sometimes appear on a smooth-triangle object.
> >>> I think it also depends on the lighting angle, and maybe even the size of the
> >>> triangles.
> >>>
> >>> What you are seeing is a known effect of raytracing the smooth normals when they
> >>> are viewed at that raking angle. (I thought that there was a short technical
> >>> explanation of this in the documentation, but I cannot find it.) The camera is
> >>> picking up the unlighted (black) interior of the object.
> >>>
> >>> If I make a low-rez height_field and add the 'smooth' keyword, the same thing
> >>> happens. The interior_texture trick is one way to try and make these artifacts
> >>> less noticable. Or try adding the 'double_illuminate' keyword to the object. If
> >>> I recall, this was a recommended 'fix' for the problem. It seems to work most of
> >>> the time, but not in every situation.
> >>
> >> Ok, thank! I am working on .. it does not seems by light position, but by the
> >> angle between WP and smooth_triangle (s) ...
> >> Many thanks again!
> >> G.
> > Bug hacked?
> > old sprites concept? I'm under no illusions, I'll do more tests, but in this way
> > I don't see the bug anymore
>
> Even better :
> interior_texture{pigment{rgbt 1}}
> or
> interior_texture{pigment{rgbf 1}}
>
> That way, no need to use any image file.
Well , I will check... anyway the gif image is only a transparence...
but I call the object twice, swapping inside/outside
Do you mean the same thing? To understand I would have to see your code on
pigments
TX!
G.


Post a reply to this message

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