Stephen <mca### [at] aolcom> wrote:
> That is the fun bit, experimenting. :-)
> If your media containers are the same size you can combine them into one
> interior. I have done this to get colour by using red, green and blue
> df3 files. Well three df3 files each with a different emission.
> This might speed up the render if it is suitable to your scene.
>
Hi Stephen, yes this is exactly what I'm doing. I placed invisible little
spheres at the corners of the bounding box of the whole object to assure that
the parts are adjusted.

>
> > Take a look at this:
> > http://www.maniacworld.com/erupting-volcano.htm
> >
>
> A sight indeed. To be enjoyed at a distance.
>

Yes indeed distance is needed. They speed up to 700 km/h and have temperatures
of 300 up 800 degrees Celsius. But still impressive.


> >> google have lots of white in them. But that is, I think, being very
> >> critical.
> >
> > I don't think it very critical. I plan to work a little bit on the colors and
> > the densities. May be I
> > change the grouping of the clouds.
> >
>
> We await with interest.
>
This will take the one or other day due to the rendering times. I have reviewed
the two lower levels now. Not completely satisfying but the best compromiss I
can yield so far. Sometimes a change of 0.01 for the scattering color changes
the image completely having this strange density maps. I'm not quite sure to
repair the density of the upper "cloud", may be I change the color to be more
white. But as Thomas said the lighter parts are blown up into the air and they
must be more easily be influenced by the wind, which is blowing here from right
to left, especially at greater altitudes.

Best regards,
Michael

Post a reply to this message

On 21/07/2013 9:37 PM, MichaelJF wrote:
> This will take the one or other day due to the rendering times. I have reviewed
> the two lower levels now. Not completely satisfying but the best compromiss I
> can yield so far. Sometimes a change of 0.01 for the scattering color changes
> the image completely having this strange density maps. I'm not quite sure to
> repair the density of the upper "cloud", may be I change the color to be more
> white. But as Thomas said the lighter parts are blown up into the air and they
> must be more easily be influenced by the wind, which is blowing here from right
> to left, especially at greater altitudes.


We have the patience. :-)

-- 
Regards
     Stephen

Post a reply to this message

Stephen <mca### [at] aolcom> wrote:
> On 21/07/2013 9:37 PM, MichaelJF wrote:
> > This will take the one or other day due to the rendering times. I have reviewed
> > the two lower levels now. Not completely satisfying but the best compromiss I
> > can yield so far. Sometimes a change of 0.01 for the scattering color changes
> > the image completely having this strange density maps. I'm not quite sure to
> > repair the density of the upper "cloud", may be I change the color to be more
> > white. But as Thomas said the lighter parts are blown up into the air and they
> > must be more easily be influenced by the wind, which is blowing here from right
> > to left, especially at greater altitudes.
>
>
> We have the patience. :-)
>
> --
> Regards
>      Stephen

Sometimes I'm not quite sure I will have the patience needed. But today I found
out the reason of my problems just by chance. I always had ribbon like
structures around my "cloud" which were annoying completelly. But they did not
come from the df3-file or the scattering or absorbing parameters or the the warp
turbulence, I would have expected them. They came from "interpolate 2" within
the density file definition. I ever thought that a cubic interpolation would be
better than a linear one only resulting in longer rendering time. But seems, I
was wrong with that.

Best regards,
Michael

Post a reply to this message

> Stephen <mca### [at] aolcom> wrote:
>> On 21/07/2013 9:37 PM, MichaelJF wrote:
>>> This will take the one or other day due to the rendering times. I have reviewed
>>> the two lower levels now. Not completely satisfying but the best compromiss I
>>> can yield so far. Sometimes a change of 0.01 for the scattering color changes
>>> the image completely having this strange density maps. I'm not quite sure to
>>> repair the density of the upper "cloud", may be I change the color to be more
>>> white. But as Thomas said the lighter parts are blown up into the air and they
>>> must be more easily be influenced by the wind, which is blowing here from right
>>> to left, especially at greater altitudes.
>>
>>
>> We have the patience. :-)
>>
>> --
>> Regards
>>       Stephen
>
> Sometimes I'm not quite sure I will have the patience needed. But today I found
> out the reason of my problems just by chance. I always had ribbon like
> structures around my "cloud" which were annoying completelly. But they did not
> come from the df3-file or the scattering or absorbing parameters or the the warp
> turbulence, I would have expected them. They came from "interpolate 2" within
> the density file definition. I ever thought that a cubic interpolation would be
> better than a linear one only resulting in longer rendering time. But seems, I
> was wrong with that.
>
> Best regards,
> Michael
>

It's a bug present in version 3.6.x. When you have areas with a value of 
zero, the interpolation cause some areas to evaluate to a negative value 
that warps around to give values that are close to 1. I think that it's 
corrected in version 3.7.

The workaround is to never have any zero in the DF3 file and to adjust 
the colour_map accordingly.

Yet another reason to upgrade to version 3.7 :)



Alain

Post a reply to this message

Alain <kua### [at] videotronca> wrote:

> > Stephen <mca### [at] aolcom> wrote:
> >> On 21/07/2013 9:37 PM, MichaelJF wrote:
> >>> This will take the one or other day due to the rendering times. I have reviewed
> >>> the two lower levels now. Not completely satisfying but the best compromiss I
> >>> can yield so far. Sometimes a change of 0.01 for the scattering color changes
> >>> the image completely having this strange density maps. I'm not quite sure to
> >>> repair the density of the upper "cloud", may be I change the color to be more
> >>> white. But as Thomas said the lighter parts are blown up into the air and they
> >>> must be more easily be influenced by the wind, which is blowing here from right
> >>> to left, especially at greater altitudes.
> >>
> >>
> >> We have the patience. :-)
> >>
> >> --
> >> Regards
> >>       Stephen
> >
> > Sometimes I'm not quite sure I will have the patience needed. But today I found
> > out the reason of my problems just by chance. I always had ribbon like
> > structures around my "cloud" which were annoying completelly. But they did not
> > come from the df3-file or the scattering or absorbing parameters or the the warp
> > turbulence, I would have expected them. They came from "interpolate 2" within
> > the density file definition. I ever thought that a cubic interpolation would be
> > better than a linear one only resulting in longer rendering time. But seems, I
> > was wrong with that.
> >
> > Best regards,
> > Michael
> >
>
> It's a bug present in version 3.6.x. When you have areas with a value of
> zero, the interpolation cause some areas to evaluate to a negative value
> that warps around to give values that are close to 1. I think that it's
> corrected in version 3.7.
>
> The workaround is to never have any zero in the DF3 file and to adjust
> the colour_map accordingly.
>
> Yet another reason to upgrade to version 3.7 :)
>
>
>
> Alain

Thanks, bur I have forgotten to mention my version. I'm using a machine which is
only some months old and I had never older versions of POV installed on this
one. The only POV installation I had ever at my actual machine is version 3.7 RC
7 (Windows version).

At my Suse laptop I have only 3.6 since I failed to compile the sources due to a
problem with the boost library. It is installed by default but the POV configure
cannot find it even after specifying the path given by yast.

Best regards,
Michael

Post a reply to this message

So, the eruption is still under work and running on another machine. Here is an
impression of the texturing I will use for the visible parts of the landscape.
Some 500.000 arbaro trees (only the foliage), a sea at the background (where
Canada should be originally, but even the 16.385x16.385 height_field of the
Puget Sound data has its limits). But most parts of the picture will be occupied
by the eruption itself, which will be more prominend as with the first wip. Not
due to changes to the df3-files but only due to changes with the media
parameters. I think I have revealed some of their mysteries by now but certainly
not all.

Best regards,
Michael

Post a reply to this message

Attachments:
Download 'pugetsound_b20130801texture.png' (1174 KB)

Preview of image 'pugetsound_b20130801texture.png'

On 1-8-2013 22:24, MichaelJF wrote:
> So, the eruption is still under work and running on another machine. Here is an
> impression of the texturing I will use for the visible parts of the landscape.
> Some 500.000 arbaro trees (only the foliage), a sea at the background (where
> Canada should be originally, but even the 16.385x16.385 height_field of the
> Puget Sound data has its limits). But most parts of the picture will be occupied
> by the eruption itself, which will be more prominend as with the first wip. Not
> due to changes to the df3-files but only due to changes with the media
> parameters. I think I have revealed some of their mysteries by now but certainly
> not all.

Looking good indeed. As far as the trees are concerned: the green ones 
to the left would need some random hue differences, like the other ones. 
There, the red trees are - imho - a bit too prominent in the whole. 
However, they all give a nice sense of scale to the whole scene.

Thomas

Post a reply to this message

Thomas de Groot <tho### [at] degrootorg> wrote:
> On 1-8-2013 22:24, MichaelJF wrote:
> > So, the eruption is still under work and running on another machine. Here is an
> > impression of the texturing I will use for the visible parts of the landscape.
> > Some 500.000 arbaro trees (only the foliage), a sea at the background (where
> > Canada should be originally, but even the 16.385x16.385 height_field of the
> > Puget Sound data has its limits). But most parts of the picture will be occupied
> > by the eruption itself, which will be more prominend as with the first wip. Not
> > due to changes to the df3-files but only due to changes with the media
> > parameters. I think I have revealed some of their mysteries by now but certainly
> > not all.
>
> Looking good indeed. As far as the trees are concerned: the green ones
> to the left would need some random hue differences, like the other ones.
> There, the red trees are - imho - a bit too prominent in the whole.
> However, they all give a nice sense of scale to the whole scene.
>
> Thomas

Thank you. Yes indeed the colors of the leaves could need a little variance. I
will look into that. The sea could be a little bit more blue. But I failed so
far to accomplish this. (I used an old material I found here at the newsgroups
and tweaked it a little bit: TdG_NorthSeaWater. I think you know who authored
this...). My main problerm is the flow itself. But it seems that I will have a
next picture within some hours. Now I abandoned the idea of several media
statements and joined all ten cloud elements into one df3-file. The result is
not the picture I intended but the best compromise I could find. Having more
than one media statement into a box seems to yield more complex interactions
than described in the POV documentation. It is not simply having a "union" with
more than one media statement or having a "difference" with more than one
density statements within a media, it is something between. I took a lot of work
to have my parts of the clouds fine (and a lot of rendering time) but putting
them together I found parts wiped out completelly and other parts "amplified" in
a way. Even the picture which will came up the next hours (hm, may be tomorrow
morning since it's slowing down actually) has a lot of parts of the original
df3-file missing.

Tomorrow I will take a break from this image. I would like to see a family of
rubber ducks around some lotus plants...
Best regards,
Michael

Post a reply to this message

On 02/08/2013 6:24 PM, MichaelJF wrote:
> Tomorrow I will take a break from this image. I would like to see a family of
> rubber ducks around some lotus plants...

LOL I know that feeling.
The landscape is looking great.

-- 
Regards
     Stephen

Post a reply to this message

Stephen <mca### [at] aolcom> wrote:
> LOL I know that feeling.

Yes, and sometimes one has to enjoy life ;-) Borrowed a lot from Gill and
eMirage (lily from eMirage (BlendSwap), water and rubber duck from Gill Tran)
here is a first wip.

Best regards,
Michael

Post a reply to this message

Attachments:
Download 'rubberducks20130804.png' (1404 KB)

Preview of image 'rubberducks20130804.png'