 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 27.11.2017 18:59, Alain wrote:
>> This is how it looks without scattering and emission. :-)
>>
>> Both seem to be required for correct colors. But look to the lowest
>> posting in this thread, that is an update and I try out an isosurface
>> there.
>>
>> My need now is, instead of fog, a media that can give me what I need.
>> See the 2nd attached image, it shows the different atmospheric layers I
>> need:
>> - ground fog just reaching above clouds
>> - orange distant layer, hiding the edges of my clouds
>>
>> http://wiki.povray.org/content/Documentation:Tutorial_Section_3.6
>>
>>
>> ---
>> http://www.avg.com
>>
>
> You have only absorption. You need scattering, NO emission and probably
> no absorption.
>
> Scattering media interact with light and get illuminated by it. It can
> show, and cast, shadows. In a radiosity scene with "media on", it can
> illuminate it's surrounding from the light it scatters. It can show
> against any background. Think of a cloud, turbid water, dust in
> suspension in the air,...
>
> Emissive media don't interact with lights and is self illuminated. In a
> radiosity scene, it can illuminate it's surrounding if you use "media
> on" in your radiosity block. Visible against darker background. Think of
> a plasma.
>
> Absorbing media cause shadow and can hide the parts of the scene behind
> it. It is never illuminated by any lights. Visible against lighter
> backgrounds. Think of dark smoke loaded with carbon particles.
>
>
Thank you! That is indeed a very good explanation! It makes me
understanding it better now, well appreciated!
And that is what I like with the POV-Ray community: the great, truly
great and helpful spirit here! After all, we all are pioneers in some
ways with each of our POV-Ray scenes.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> That image really looks almost like a dream!!! Congrats! Absolutely
> impressive!
>
> I think, when I adapt this scene (thanks also a lot for your scene
> code), I will make the orange distance haze less high but more dense so
> the planet cannot be seen through. I will try to remove the green lower
> edge of the orange haze. But other than that, your scene is PERFECT!
>
> ERROR ALERT
>
> When trying to render your scene, POV-Ray errors with the message of a
> missing } in front of the word "eccentricity". Can you correct that error?
>
> My initial wish was, when i would have finished that scene, to make it
> available to all POV-Ray users, even offering it as a ready-to-insert
> scene code. But with all the great POV-Ray community members that helped
> me so much with their own code, I feel like I have to ask them for their
> permission. I will do that, when my scene is complete.
>
> Big thanks again!!!
>
>
>
> ---
> http://www.avg.com
>
It was commented out, but the line got wraped at the wrong place when
posting.
Remove eccentricity or add // in front of it.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Alain <kua### [at] videotron ca> wrote:
>
> > That image really looks almost like a dream!!! Congrats! Absolutely
> > impressive!
> >
> > I think, when I adapt this scene (thanks also a lot for your scene
> > code), I will make the orange distance haze less high but more dense so
> > the planet cannot be seen through. I will try to remove the green lower
> > edge of the orange haze. But other than that, your scene is PERFECT!
> >
> > ERROR ALERT
> >
> > When trying to render your scene, POV-Ray errors with the message of a
> > missing } in front of the word "eccentricity". Can you correct that error?
> >
> > My initial wish was, when i would have finished that scene, to make it
> > available to all POV-Ray users, even offering it as a ready-to-insert
> > scene code. But with all the great POV-Ray community members that helped
> > me so much with their own code, I feel like I have to ask them for their
> > permission. I will do that, when my scene is complete.
> >
>
> It was commented out, but the line got wraped at the wrong place when
> posting.
>
> Remove eccentricity or add // in front of it.
Thanks Alain! Yes, sorry, I had to wait to see the scene posted so I didn't know
it had line wrapped. You will get accustomed to that if you look at more of
these text scene postings! ;-)
Wrong line wrap is (mostly) okay, just a mess to read. It's those commented
parts that will error.
Wish you good luck adjusting the color bands of the atmosphere. I couldn't get
it any better myself after a couple hours so I gave up trying anymore. I think
it's because of the gradient y mixed with spherical warp, not really sure.
Just that every time I moved the index values it changed in ways (both altitude
AND color!) I wasn't able to get correct like I wanted.
And then there's that obscuring the background or shadowed objects with media...
I've always had trouble it. I hope you get it done!
Bob
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 27.11.2017 19:32, Alain wrote:
>
>> That image really looks almost like a dream!!! Congrats! Absolutely
>> impressive!
>>
>> I think, when I adapt this scene (thanks also a lot for your scene
>> code), I will make the orange distance haze less high but more dense so
>> the planet cannot be seen through. I will try to remove the green lower
>> edge of the orange haze. But other than that, your scene is PERFECT!
>>
>> ERROR ALERT
>>
>> When trying to render your scene, POV-Ray errors with the message of a
>> missing } in front of the word "eccentricity". Can you correct that
>> error?
>>
>> My initial wish was, when i would have finished that scene, to make it
>> available to all POV-Ray users, even offering it as a ready-to-insert
>> scene code. But with all the great POV-Ray community members that helped
>> me so much with their own code, I feel like I have to ask them for their
>> permission. I will do that, when my scene is complete.
>>
>> Big thanks again!!!
>>
>>
>>
>> ---
>> http://www.avg.com
>>
>
> It was commented out, but the line got wraped at the wrong place when
> posting.
>
> Remove eccentricity or add // in front of it.
>
Thanks!
Besides, what does "exentricity" do? Can't find it in the help file...
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Sven Littkowski <I### [at] SvenLittkowskiname> wrote:
> Thanks!
>
> Besides, what does "exentricity" do? Can't find it in the help file...
Glad to help.
Well, if spelled right... LOL
Sorry, I'm just being funny because I had seen the talk about language
translation-- obviously not about spelling. Anyway...
It's only used for media scattering type 5 and is for alignment changes of light
sources. So eccentricity 0 scatters light in all directions (like isotropic or
type 1), while 1 or -1 is oriented with light_source(s). Positive number is
toward light, negative away from light.
Online help link:
http://wiki.povray.org/content/Reference:Media_Types
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 27-11-2017 18:29, Sven Littkowski wrote:
> On 27.11.2017 10:15, Bald Eagle wrote:
>> I'm pretty sure that unless people are generating scene files with a 3rd party
>> application (Pose-Ray, etc), then the standard Left-Handed coordinate system
>> should be the default.
>> I'm not sure what coordinate system you're using - or why.
>
> Hi. Well, in my coordinate system, I am using the "Y" axis for the
> height. But the cloud used a different axis for its height. I had to
> rotate. :-)
>
> On 27.11.2017 10:15, Bald Eagle wrote:
>> Actually defining a COLOR based on density would require a much more complex
>> coding, involving functions, and perhaps a 3-color separation scheme such as
>> Stephen uses for his DF3's
>
> I just don't know. I never usually work with media and density. Always
> only with regular shapes and differences only. But I believe, I need
> such density effect here.
>
Density is best to be used for what it is made for: density. So, the
colour used in a density's colour_map are shades of grey from black to
white.
If you want the media to be coloured, then that can be achieved within
the emission/absorption/scattering parameters. However, clouds by
themselves are always white/grey (water vapour, remember?). Adding
colour makes no sense, except if you want to show alien additives like
pollution or ashes (volcanoes).
--
Thomas
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 27-11-2017 23:11, omniverse wrote:
> I used Thomas' scene to modify (maybe hack is the word) and had much trouble
> with transparency of the media, especially when objects within it are backlit or
> in shadow.
>
> I finally got a result similar to the photo, but it took some serious trial and
> error to get the colors. And I tried various extinction values, to name one
> example. Just look at all the media color vectors and you will see what I mean.
>
> I also used radiosity with it too, so I added sphere for ground. I had to widen
> that to meet horizon edge better than simply have a shell of
> cloud/fog/atmosphere, and sky disc of blue-white to try and make those cloud
> colors interact with radiosity. Which was due to the reddened atmosphere,
> otherwise it turned very yellow.
>
> There was strange stuff about the atmosphere y-axis scale when changing index
> values, but I shouldn't go into all that here. Just be forewarned that using
> other index values might alter the haze layer (orange-yellow portion) in weird
> ways. You will also notice I turned the media into spherical warps, and rotated
> the atmosphere in attempt to get haze layer out of near distance.
>
> Like I said, it's more a hack rather than modified with certainty of outcome.
>
> I might be forgetting things, I was changing almost every aspect but luckily
> Thomas got me to the starting point well enough. Scene follows:
>
I am curious :-)
I shall have a look at what you brewed up. The scene looks nice indeed!
--
Thomas
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On 28/11/2017 08:01, Thomas de Groot wrote:
> Density is best to be used for what it is made for: density. So, the
> colour used in a density's colour_map are shades of grey from black to
> white.
>
> If you want the media to be coloured, then that can be achieved within
> the emission/absorption/scattering parameters. However, clouds by
> themselves are always white/grey (water vapour, remember?). Adding
> colour makes no sense, except if you want to show alien additives like
> pollution or ashes (volcanoes).
I concur ("agree" to save you looking it up).
--
Regards
Stephen
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Thomas de Groot <tho### [at] degrootorg> wrote:
> However, clouds by
> themselves are always white/grey (water vapour, remember?). Adding
> colour makes no sense,
I'd say to be entirely acurate, clouds themselves are colorless, or even more
accurately - reflect the colors surrounding them.
The tiny water droplets are clear, as are polar bear hairs, but due to the
extreme curvature, reflect light back toward the viewer, refract the light, due
to the ior, and scatter it.
Rainbows are just lit-up water vapor (and are circular).
I have, for the past year taken much more notice of things "out there" IRL, and
the clouds are almost _never_ white/grey - they are all manner of pink and
purple, and orange, red and bluish-gray....
It depends on the time of day.
Just nitpicking, and "keeping it real". ;)
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
I have started to work on your scene, to adapt it even more.
Yes, you are right - changing the atmospheric colors does not lead to
straight, expected results, but to unexpectable new colors. I believe
(but I have no clue about media and density), that the reason for this
color problem lays with the fact, that you specify the colors within the
density map. I wonder, if there is a way to use neutral shades for the
density map, and move the color map into the pigment statement right
below the coordinates of the cloud layer.
Also, seeing that the horizon is too curvy, I try out using a box
instead of a cylinder for the cloud layer. I now use the keyword "boxed"
for "density" instead"spherical", but the horizon still looks like that
of a cylinder. Can you advise? See my altered source code below.
Once I got the environment right, then I will work on the architecture
of the skyscrapers. I have some weird visions... :-D
Basically, the task is now to get the horizon straight, and then to find
a way to change the colors the way we want.
UPDATE
Horizon okay now.
I wonder, if I can use these two suns as light sources instead of a
traditional light_source, when filling them with media?
------------------
---
http://www.avg.com
Post a reply to this message
Attachments:
Download 'sl - cloud cities - omniverse - 02.jpg' (90 KB)
Preview of image 'sl - cloud cities - omniverse - 02.jpg'
|
|
| |
| |
|
|
|
|
| |
|
|
