POV-Ray : Newsgroups : povray.newusers : Is there a function... Server Time
4 Nov 2024 13:02:37 EST (-0500)
  Is there a function... (Message 1 to 7 of 7)  
From: Florian Rustedt
Subject: Is there a function...
Date: 9 Jul 2003 08:00:56
Message: <3f0c03f8@news.povray.org>
---------------------------------------
1.  ...that makes simple object "roundedged", so that all is looking more
realistic?

Be aware, i do NOT mean antialiasing. It's just the fact that nothin in
reality is as sharp-edged, as the results in povray are, what theoretically
is a good thing, because it has to be mathematically exact.

But if i am constructing p.e. an chair or a table, there is an enormous
effort for rounding the edges making it look like REAL wood, plastic, etc,
because real materials (except steel) are never as sharp, as they are in
pov, because they are not hard enough...
---------------------------------------
2.  ...that i can apply to make the light, shadows and surfaces look more
real?

This is based up on the fact, that all is looking a little bit plastic like,
equal if i add some finishes or not. Another thing is the sharpeness in
every depth, what a normal photo never is.

In other words: are there some very basic steps i can apply to my scene or
rendered picture that generally realisticalize it a little bit more??


Post a reply to this message

From: Tim Nikias v2 0
Subject: Re: Is there a function...
Date: 9 Jul 2003 10:09:47
Message: <3f0c222b$1@news.povray.org>
1. Nope. Not a simple object.
You could try and construct your object with Christoph Hormanns
isoCSG, and try to blob the edges away a little, I've never done so
and don't have any experience with it, so I'm not even sure if
it'll work. But that's the only idea I can come up with, aside of modelling
with some other program than POV-Ray.

2. Light, shadows and surfaces
Well, for the light & shadows, use area_lights, fade_power, radiosity
and photons, and you've covered pretty much every realistic
effect possible (though nothing that resembles effects occuring with
different wavelengths, like bending around corners and such...).
For the sharpness of the image, look at focal blur, which covers
you're photographic "everything sharp" problem.

For surfaces, well, you've got to learn all tids and bits about finish,
normals and textures, but mostly probably about normals and
finishes, like reflections, brilliance, specular highlighting, fresnel
etc...


-- 
Tim Nikias v2.0
Homepage: http://www.digitaltwilight.de/no_lights


> ---------------------------------------
> 1.  ...that makes simple object "roundedged", so that all is looking more
> realistic?
>
> Be aware, i do NOT mean antialiasing. It's just the fact that nothin in
> reality is as sharp-edged, as the results in povray are, what
theoretically
> is a good thing, because it has to be mathematically exact.
>
> But if i am constructing p.e. an chair or a table, there is an enormous
> effort for rounding the edges making it look like REAL wood, plastic, etc,
> because real materials (except steel) are never as sharp, as they are in
> pov, because they are not hard enough...
> ---------------------------------------
> 2.  ...that i can apply to make the light, shadows and surfaces look more
> real?
>
> This is based up on the fact, that all is looking a little bit plastic
like,
> equal if i add some finishes or not. Another thing is the sharpeness in
> every depth, what a normal photo never is.
>
> In other words: are there some very basic steps i can apply to my scene or
> rendered picture that generally realisticalize it a little bit more??


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.495 / Virus Database: 294 - Release Date: 30.06.2003


Post a reply to this message

From: Slashdolt
Subject: Re: Is there a function...
Date: 9 Jul 2003 11:53:29
Message: <3f0c3a79$1@news.povray.org>
Tim is right.  But once you add all of those features into your scene, don't
be surprised if render time goes from a few minutes to several hours or even
days.

Also, in regards to using the isoCSG library, I've used it quite a bit.  It
takes some getting used to doing everything in functions, but you can really
get some realistic effects with your objects that are just not possible in
any other way that I know of.  Isosurfaces are just plain better.  I wish
everything was an isosurface...

-- 
Slash


Post a reply to this message

From: Christopher James Huff
Subject: Re: Is there a function...
Date: 9 Jul 2003 12:51:59
Message: <cjameshuff-DC72B9.11490409072003@netplex.aussie.org>
In article <3f0c03f8@news.povray.org>,
 Florian Rustedt <flo### [at] rustedtde> wrote:

> ---------------------------------------
> 1.  ...that makes simple object "roundedged", so that all is looking more
> realistic?

No there isn't. But there are macros in shapes.inc for making rounded 
versions of some common shapes...boxes, cylinders, cones.


> 2.  ...that i can apply to make the light, shadows and surfaces look more
> real?
> 
> This is based up on the fact, that all is looking a little bit plastic like,
> equal if i add some finishes or not. Another thing is the sharpeness in
> every depth, what a normal photo never is.

    There are many separate features that combine for this. The first 
thing you mention seems to be about surface imperfections...a flat 
surface in POV appears perfectly flat, unlike most real-world surfaces. 
You can use the normal feature to make them appear uneven or bumpy.

    Also, you need to use realistic lighting. Don't be afraid of using 
light values greater than 1. Try designing your scene with an ambient of 
0 for all non-glowing objects. The easiest way to do this is to put 
"#default {finish {ambient 0 diffuse 1}}" at the beginning of your 
scene. This improves contrast and the 3D look of your scene. A fill 
light at the camera location can still provide illumination into 
shadows, without the flatness of ambient lighting. Try radiosity as 
well...radiosity simulates indirect lighting by light diffusely 
reflecting off of nearby objects, like the glow from a sunlit spot in a 
dark room. If you have highly reflective or transparent objects, photon 
mapping can be a good idea. Photon mapping simulates specular 
(mirror-like) reflective and refractive caustics, like light shining 
through a colored glass. This can make a scene appear much more 
realistic with little effort.

    Other things depend on your scene. An outdoor scene with far objects 
will often show atmospheric haze. The fog feature is usually best for 
this. For dense fog, scattering media may be better, as it will show 
light beams and shadows that pass through it. As for the sharpness, 
there is a focal blur feature.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/


Post a reply to this message

From: Tom Melly
Subject: Re: Is there a function...
Date: 10 Jul 2003 04:59:21
Message: <3f0d2ae9$1@news.povray.org>
"Florian Rustedt" <flo### [at] rustedtde> wrote in message
news:3f0c03f8@news.povray.org...
> ---------------------------------------
> 1.  ...that makes simple object "roundedged", so that all is looking more
> realistic?
>

Take a look at "superellipsoid" (6.5.1.11) for rounded boxes and cylinders (a
much under-used primitive imho).


Post a reply to this message

From: Christopher James Huff
Subject: Re: Is there a function...
Date: 10 Jul 2003 12:15:18
Message: <cjameshuff-DCCF96.11121210072003@netplex.aussie.org>
In article <3f0d2ae9$1@news.povray.org>,
 "Tom Melly" <tom### [at] tomandlucouk> wrote:

> Take a look at "superellipsoid" (6.5.1.11) for rounded boxes and cylinders (a
> much under-used primitive imho).

    Two problems: 1) you can't specify a radius for the rounding, 2) 
this is because it doesn't have one. The superellipsoid is incapable of 
making a rounded cone or box, though it will make shapes that closely 
resemble them. The round never transitions into a flat cylinder or box 
edge...sometimes useful, but often undesired.

    Precise CSG with a superellipsoid is difficult, and CSG of 
cylinders, spheres, toruses, and boxes is also more flexible. With a 
superellipsoid, you always get rounded pseudo-cubes and cylinders with a 
length of 2 units and a radius of 1. Uneven scaling gives you uneven 
rounding, and positioning is inconvenient.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: chr### [at] tagpovrayorg
http://tag.povray.org/


Post a reply to this message

From:
Subject: Re: Is there a function...
Date: 10 Jul 2003 17:05:35
Message: <3f0dd51f$1@news.povray.org>
Hi Florian,

I've written an includefile for creation of rounded objects. It is not
an automatic "rounder" of arbitrary objects and it can not create all
rounded shapes, but I can't live without it.

Basically, you can take the volume between two parallel planes, make
a closed cut (perpendicular to these planes) along straight lines and
circular segments, then round the corners lying in the planes.

Example picture:
   povray.binaries.images, 23rd and 26th January 2003
   "Round/bevel: include file demo [51 KB JPG]"
Include file and "slide show" demo:
   povray.binaries.scene-files, 23rd January
   "Round/bevel: Include file"
Tutorial:
   same thread, 26th January
   "Round/bevel: Mini-Tutorial; Test-Arena"

The include file has an additional short german introduction and comments.

   Sputnik

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

fr### [at] computermuseumfh-kielde
----------------------------


Post a reply to this message

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