POV-Ray : Newsgroups : povray.binaries.images : Bluebell Wood Server Time: 25 Jan 2021 23:11:00 GMT
  Bluebell Wood (Message 12 to 21 of 21)  
<<< Previous 10 Messages Goto Initial 10 Messages
From: Paolo Gibellini
Subject: Re: Bluebell Wood
Date: 18 Nov 2020 08:38:14
Message: <5fb4dd76$1@news.povray.org>
Norbert Kern wrote on 13/11/2020 17:32:
> Hi,
> 
> There is something  fascinating about bluebell woods. They exist in Great
> Britain, Ireland, Belgium and Germany (only two very small spots). Bluebells are
> an indicator for ancient woodlands, so bluebell woods are likely to date back to
> at least 1600 (from Wikipedia).
> 
[...]
> 
> Happy rendering,
> Norbert
> 

A magnificent scenery, in which it would be nice to immerse yourself, 
full of details and with a certain harmony.
A beautiful image!

Paolo


Post a reply to this message

From: Thomas de Groot
Subject: Re: Bluebell Wood
Date: 19 Nov 2020 08:19:07
Message: <5fb62a7b$1@news.povray.org>
What I always find difficult to emulate is the light combined with the 
texture/transparency of the leaves. I have your technique about the 
leaves (faked translucency mapping) and also use double_illuminate. It 
is the atmospheric media which is often difficult to do. Isotropy is 
fairly straightforward, but I often prefer the use of Henyey-Greenstein 
scattering withou too extreme eccentricity.

-- 
Thomas


Post a reply to this message

From: Alain Martel
Subject: Re: Bluebell Wood
Date: 19 Nov 2020 18:40:32
Message: <5fb6bc20$1@news.povray.org>
Le 2020-11-19 à 03:19, Thomas de Groot a écrit :
> What I always find difficult to emulate is the light combined with the 
> texture/transparency of the leaves. I have your technique about the 
> leaves (faked translucency mapping) and also use double_illuminate. It 
> is the atmospheric media which is often difficult to do. Isotropy is 
> fairly straightforward, but I often prefer the use of Henyey-Greenstein 
> scattering withou too extreme eccentricity.
> 

Instead of double_illuminate, you should us the back side illumination. 
Starting with version 3.7, it's done by using two values after diffuse. 
It gives you much more control.
Example : diffuse 0.6 0.3
Just remember that the two values should add to less than 1.

If you use double_illuminate with a diffuse value of 0.6, what you 
effectively get is this : diffuse 0.6 0.6
This is not realistic at all.

You can also add some filter to the pigment. Keep that pretty low.


Post a reply to this message

From: Thomas de Groot
Subject: Re: Bluebell Wood
Date: 20 Nov 2020 07:46:25
Message: <5fb77451$1@news.povray.org>
Op 19/11/2020 om 19:40 schreef Alain Martel:
> Le 2020-11-19 à 03:19, Thomas de Groot a écrit :
>> What I always find difficult to emulate is the light combined with the 
>> texture/transparency of the leaves. I have your technique about the 
>> leaves (faked translucency mapping) and also use double_illuminate. It 
>> is the atmospheric media which is often difficult to do. Isotropy is 
>> fairly straightforward, but I often prefer the use of 
>> Henyey-Greenstein scattering withou too extreme eccentricity.
>>
> 
> Instead of double_illuminate, you should us the back side illumination. 
> Starting with version 3.7, it's done by using two values after diffuse. 
> It gives you much more control.
> Example : diffuse 0.6 0.3
> Just remember that the two values should add to less than 1.
> 
> If you use double_illuminate with a diffuse value of 0.6, what you 
> effectively get is this : diffuse 0.6 0.6
> This is not realistic at all.
> 
> You can also add some filter to the pigment. Keep that pretty low.
> 

Of course! and that is what I meant: I use backside illumination in my 
scenes, and misspelled it into double_illuminate here... ;-/

-- 
Thomas


Post a reply to this message

From: Bill Pragnell
Subject: Re: Bluebell Wood
Date: 20 Nov 2020 08:45:00
Message: <web.5fb781669fb6f5f7b96893c00@news.povray.org>
Alain Martel <kua### [at] videotronca> wrote:
> Instead of double_illuminate, you should us the back side illumination.
> Starting with version 3.7, it's done by using two values after diffuse.
> It gives you much more control.
> Example : diffuse 0.6 0.3
> Just remember that the two values should add to less than 1.

Ah! Another 'new' feature that I didn't notice! And as luck would have it I'm
idly tinkering with something that might benefit from its usage.

Ta


Post a reply to this message

From: Bill Pragnell
Subject: Re: Bluebell Wood
Date: 20 Nov 2020 08:50:01
Message: <web.5fb7827f9fb6f5f7b96893c00@news.povray.org>
"Norbert Kern" <nor### [at] t-onlinede> wrote:
> So I collected much more than 1000 trees (and many more plants too) during the
> last 20 years - whereever possible.

Interesting. Presumably you have some kind of sorting system so you can find
what you need? I collect some things, but not much in POV-Ray - I enjoy the
challenge of doing as much as possible from scratch (or at least with my own
creations). Unfortunately this means many projects fall by the wayside.

> Luckily there are sites as https://archive3d.net/?tag=Tree to provide good
> meshes for free.

Thanks for the link; I'll check it out!

Bill


Post a reply to this message

From: Norbert Kern
Subject: Re: Bluebell Wood
Date: 21 Nov 2020 21:05:07
Message: <web.5fb97fe19fb6f5f7aa6014a80@news.povray.org>
Alain Martel <kua### [at] videotronca> wrote:
> Le 2020-11-19 à 03:19, Thomas de Groot a écrit :
> > What I always find difficult to emulate is the light combined with the
> > texture/transparency of the leaves. I have your technique about the
> > leaves (faked translucency mapping) and also use double_illuminate. It
> > is the atmospheric media which is often difficult to do. Isotropy is
> > fairly straightforward, but I often prefer the use of Henyey-Greenstein
> > scattering withou too extreme eccentricity.
> >
>
> Instead of double_illuminate, you should us the back side illumination.
> Starting with version 3.7, it's done by using two values after diffuse.
> It gives you much more control.
> Example : diffuse 0.6 0.3
> Just remember that the two values should add to less than 1.
>
> If you use double_illuminate with a diffuse value of 0.6, what you
> effectively get is this : diffuse 0.6 0.6
> This is not realistic at all.
>
> You can also add some filter to the pigment. Keep that pretty low.



I wasn't aware of this - many thanks, Alain!

Norbert


Post a reply to this message

From: Norbert Kern
Subject: Re: Bluebell Wood
Date: 21 Nov 2020 22:00:00
Message: <web.5fb98c9e9fb6f5f7aa6014a80@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> What I always find difficult to emulate is the light combined with the
> texture/transparency of the leaves. I have your technique about the
> leaves (faked translucency mapping) and also use double_illuminate. It
> is the atmospheric media which is often difficult to do. Isotropy is
> fairly straightforward, but I often prefer the use of Henyey-Greenstein
> scattering withou too extreme eccentricity.
>
> --
> Thomas



Hi Thomas,

in my last images I divide them in a diffuse and a media part. It doubles the
render times, but there is no way to reproduce the quality when doing it
combined.

I'm not totally sure, but some related issues seem to evaporate by this approach
too...
The way I do the media render is to simply multiply the diffuse, specular, phong
and reflection values with zero (I hate this procedure by the way).


And wow, you are really in the media types - fantastic!
I simply tested the media types and used the best looking - here's my setup


#version 3.7;

global_settings {
        assumed_gamma 1
        max_trace_level 5
        noise_generator 2
}

#include "stdinc.inc"

light_source {
        <0,0,95131>,
        srgb 2.5
        area_light <1000,0,0>, <0,1000,0> 5,5 adaptive 0 jitter circular orient
        rotate <-52,160,0>
}

box {
        <-35,-0.8,-80>, <35,90,30>
        hollow
        material {
                texture {
                        pigment {color rgbt 1}
                }
                interior {
                        media {
                                scattering {3, 0.005}
                                intervals 1
                                samples 50
                        }
                }
        }
}

I mostly use standard finishes (65 meshes used in this image, perhaps 250
textures - no way to adapt them all individually - so "finish {specular 0.3
roughness 0.0003 diffuse 0.6 ambient 0}" has to do it...

Norbert


Post a reply to this message

From: Thomas de Groot
Subject: Re: Bluebell Wood
Date: 22 Nov 2020 08:04:24
Message: <5fba1b88$1@news.povray.org>
Op 21/11/2020 om 22:54 schreef Norbert Kern:
> Thomas de Groot <tho### [at] degrootorg> wrote:
>> What I always find difficult to emulate is the light combined with the
>> texture/transparency of the leaves. I have your technique about the
>> leaves (faked translucency mapping) and also use double_illuminate. It
>> is the atmospheric media which is often difficult to do. Isotropy is
>> fairly straightforward, but I often prefer the use of Henyey-Greenstein
>> scattering withou too extreme eccentricity.
>>
>> --
>> Thomas
> 
> 
> 
> Hi Thomas,
> 
> in my last images I divide them in a diffuse and a media part. It doubles the
> render times, but there is no way to reproduce the quality when doing it
> combined.
> 
> I'm not totally sure, but some related issues seem to evaporate by this approach
> too...
> The way I do the media render is to simply multiply the diffuse, specular, phong
> and reflection values with zero (I hate this procedure by the way).
> 

Interesting. So, if I understand you correctly, you combine two separate 
renders, one without media but with fullfledged finish, and one with the 
media but with zeroed finish. Forgive me, I think you have already 
explained this in the past, but I cannot find the place.

> 
> And wow, you are really in the media types - fantastic!
> I simply tested the media types and used the best looking - here's my setup

The media type used depends heavily imo of the light position in the 
scene and the effect wanted. Sometimes, isotropic media is just fine, 
sometimes you need a more sophisticated approach.

> 
> 
> #version 3.7;
> 
> global_settings {
>          assumed_gamma 1
>          max_trace_level 5
>          noise_generator 2
> }
> 
> #include "stdinc.inc"
> 
> light_source {
>          <0,0,95131>,
>          srgb 2.5
>          area_light <1000,0,0>, <0,1000,0> 5,5 adaptive 0 jitter circular orient
>          rotate <-52,160,0>
> }
> 
> box {
>          <-35,-0.8,-80>, <35,90,30>
>          hollow
>          material {
>                  texture {
>                          pigment {color rgbt 1}
>                  }
>                  interior {
>                          media {
>                                  scattering {3, 0.005}
>                                  intervals 1
>                                  samples 50
>                          }
>                  }
>          }
> }
> 
> I mostly use standard finishes (65 meshes used in this image, perhaps 250
> textures - no way to adapt them all individually - so "finish {specular 0.3
> roughness 0.0003 diffuse 0.6 ambient 0}" has to do it...
> 

Thanks indeed. I shall play with this.

-- 
Thomas


Post a reply to this message

From: Kenneth
Subject: Re: Bluebell Wood
Date: 22 Nov 2020 15:05:01
Message: <web.5fba7db79fb6f5f7d98418910@news.povray.org>
"Norbert Kern" <nor### [at] t-onlinede> wrote:
> Hi,
>
> There is something  fascinating about bluebell woods.

Absolutely beautiful. Your renders are a real inspiration to all of us here.
I've never attempted making any scene as complex as this!


Post a reply to this message

<<< Previous 10 Messages Goto Initial 10 Messages

Copyright 2003-2008 Persistence of Vision Raytracer Pty. Ltd.