I have a problem...

I've surrounded a sphere with media which isn't taking kindly to being
scaled.  The model is a union of earth and a sphere of media surrounding it,
simulating atmosphere.  When I try to scale this union the media becomes
increasingly whiter and brighter until the image map of earth isn't visible.

Is there a reason why this is happening?  Is there a way to fix this?

 Thanks,
-Chris-

Post a reply to this message

Attachments:
Download 'object31_earth002.mdl.dat' (3 KB) Download 'earth001.GIF' (36 KB)

Preview of image 'earth001.GIF'

One correction...that horribly dithered GIF wasn't supposed to come 
along.  Included is the correct image-map and some samples.

 Thanks guys;)
-Chris-

Before object scaling.



After object scaling.






Chris Spencer <chr### [at] bluelectrodecom> wrote in message 
news:388a6470@news.povray.org...
> I have a problem...
> 
> I've surrounded a sphere with media which isn't taking kindly to being
> scaled.  The model is a union of earth and a sphere of media 
surrounding it,
> simulating atmosphere.  When I try to scale this union the media 
becomes
> increasingly whiter and brighter until the image map of earth isn't 
visible.
> 
> Is there a reason why this is happening?  Is there a way to fix this?
> 
>  Thanks,
> -Chris-
> 
> 
>

Post a reply to this message

Attachments:
Download 'iso-8859-1' (2 KB)

You always have to oppose scale for media when scaling the object it's in.  If
the scaling of the container object is first it isn't such a problem (?), if
scaled after the media is in place then it is.  If the object is scale
<100,50,10> for example (at the end of the entire object statement) then go back
into the media statement and use a scale <1/100,1/50,1/10> to correct for the
increase in media density, etc.  Opposite true too.

Bob

"Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
news:388a6470@news.povray.org...
| I have a problem...
|
| I've surrounded a sphere with media which isn't taking kindly to being
| scaled.  The model is a union of earth and a sphere of media surrounding it,
| simulating atmosphere.  When I try to scale this union the media becomes
| increasingly whiter and brighter until the image map of earth isn't visible.
|
| Is there a reason why this is happening?  Is there a way to fix this?
|
|  Thanks,
| -Chris-
|
|
|

Post a reply to this message

Bob Hughes <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
news:388af1c9@news.povray.org...
> You always have to oppose scale for media when scaling the object it's in.
If
> the scaling of the container object is first it isn't such a problem (?),
if scaled after the media is in place then it is.

What?  Do you mean scaling the entire texture w/ media or just the media or
just the density or just the....etc.?

> If the object is scale
> <100,50,10> for example (at the end of the entire object statement) then
go back
> into the media statement and use a scale <1/100,1/50,1/10> to correct for
the
> increase in media density, etc.  Opposite true too.

I scaled the object to <1000, 1000, 1000> but when I added a transformation
to the density of <.001, .001, .001> the media disappeared completely.
I think I understand your concept but I'm not quite sure what I'm supposed
to be transforming.

>
> Bob
>
> "Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
> news:388a6470@news.povray.org...
> | I have a problem...
> |
> | I've surrounded a sphere with media which isn't taking kindly to being
> | scaled.  The model is a union of earth and a sphere of media surrounding
it,
> | simulating atmosphere.  When I try to scale this union the media becomes
> | increasingly whiter and brighter until the image map of earth isn't
visible.
> |
> | Is there a reason why this is happening?  Is there a way to fix this?
> |
> |  Thanks,
> | -Chris-
> |
> |
> |
>
>

 Thanks,
-Chris-

Post a reply to this message

object { ContainerObject // scale 1000 here? media scale effect not present.
 material {
  texture { pigment { rgbf 1 } }
   interior { media {
                            scattering { 1, 1 }
                             density { 1 }
                            scale <.001,.001,.001> // opposed scale of object
scale
                            }
                }
    }
 // object scale.  If <.001,.001,.001> here then 1000 X in media.
 scale <1000,1000,1000>
}


This way should do okay.  You're scaling the media then to counter object
resize.  When the object size starts off large the media isn't affected by that
scaling, ie. 'object { ContainerObject scale <1000,1000,1000>' etc. though the
texture pattern and all isn't fit to it in a unit anymore so scaling at the end
is usually done, although the scaling counter-effect solution doesn't need to be
used in this way if the container is already large (or small) before media is
applied.
Hope this solves it for you now.

Bob

"Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
news:388b5ddf@news.povray.org...
|
| Bob Hughes <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
| news:388af1c9@news.povray.org...
| > You always have to oppose scale for media when scaling the object it's in.
| If
| > the scaling of the container object is first it isn't such a problem (?),
| if scaled after the media is in place then it is.
|
| What?  Do you mean scaling the entire texture w/ media or just the media or
| just the density or just the....etc.?
|
| > If the object is scale
| > <100,50,10> for example (at the end of the entire object statement) then
| go back
| > into the media statement and use a scale <1/100,1/50,1/10> to correct for
| the
| > increase in media density, etc.  Opposite true too.
|
| I scaled the object to <1000, 1000, 1000> but when I added a transformation
| to the density of <.001, .001, .001> the media disappeared completely.
| I think I understand your concept but I'm not quite sure what I'm supposed
| to be transforming.
|
| >
| > Bob
| >
| > "Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
| > news:388a6470@news.povray.org...
| > | I have a problem...
| > |
| > | I've surrounded a sphere with media which isn't taking kindly to being
| > | scaled.  The model is a union of earth and a sphere of media surrounding
| it,
| > | simulating atmosphere.  When I try to scale this union the media becomes
| > | increasingly whiter and brighter until the image map of earth isn't
| visible.
| > |
| > | Is there a reason why this is happening?  Is there a way to fix this?
| > |
| > |  Thanks,
| > | -Chris-
| > |
| > |
| > |
| >
| >
|
|  Thanks,
| -Chris-
|
|

Post a reply to this message

Thanks, but it didn't work.  Although this has solved the problem of the
media appearing completely white, now it can not be seen at all.

-Chris-

> object { ContainerObject // scale 1000 here? media scale effect not
present.
>  material {
>   texture { pigment { rgbf 1 } }
>    interior { media {
>                             scattering { 1, 1 }
>                              density { 1 }
>                             scale <.001,.001,.001> // opposed scale of
object
> scale
>                             }
>                 }
>     }
>  // object scale.  If <.001,.001,.001> here then 1000 X in media.
>  scale <1000,1000,1000>
> }
>
>
> This way should do okay.  You're scaling the media then to counter object
> resize.  When the object size starts off large the media isn't affected by
that
> scaling, ie. 'object { ContainerObject scale <1000,1000,1000>' etc. though
the
> texture pattern and all isn't fit to it in a unit anymore so scaling at
the end
> is usually done, although the scaling counter-effect solution doesn't need
to be
> used in this way if the container is already large (or small) before media
is
> applied.
> Hope this solves it for you now.
>
> Bob
>
> "Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
> news:388b5ddf@news.povray.org...
> |
> | Bob Hughes <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
> | news:388af1c9@news.povray.org...
> | > You always have to oppose scale for media when scaling the object it's
in.
> | If
> | > the scaling of the container object is first it isn't such a problem
(?),
> | if scaled after the media is in place then it is.
> |
> | What?  Do you mean scaling the entire texture w/ media or just the media
or
> | just the density or just the....etc.?
> |
> | > If the object is scale
> | > <100,50,10> for example (at the end of the entire object statement)
then
> | go back
> | > into the media statement and use a scale <1/100,1/50,1/10> to correct
for
> | the
> | > increase in media density, etc.  Opposite true too.
> |
> | I scaled the object to <1000, 1000, 1000> but when I added a
transformation
> | to the density of <.001, .001, .001> the media disappeared completely.
> | I think I understand your concept but I'm not quite sure what I'm
supposed
> | to be transforming.
> |
> | >
> | > Bob
> | >
> | > "Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
> | > news:388a6470@news.povray.org...
> | > | I have a problem...
> | > |
> | > | I've surrounded a sphere with media which isn't taking kindly to
being
> | > | scaled.  The model is a union of earth and a sphere of media
surrounding
> | it,
> | > | simulating atmosphere.  When I try to scale this union the media
becomes
> | > | increasingly whiter and brighter until the image map of earth isn't
> | visible.
> | > |
> | > | Is there a reason why this is happening?  Is there a way to fix
this?
> | > |
> | > |  Thanks,
> | > | -Chris-
> | > |
> | > |
> | > |
> | >
> | >
> |
> |  Thanks,
> | -Chris-
> |
> |
>
>

Post a reply to this message

Gee, I'm not winning at this then.  Sorry.
Well I just did a quick check of it here.
The density { 1 } stated before is really supposed to be density { rgb 1 } for
the example, and you would obviously need to compensate the view size with a
camera zoomed in or out.
It's not right, not like as expected from earlier media scaling I had done
myself.  Most notable is that emission and/or absorption make a great deal of
difference (I may not have ever scaled without them before) than just using the
scattering alone or density alone or scattering and density.  In other words, so
many variations are possible it's difficult to narrow down the problem.
I checked with both official 3.1g and MegaPOV 0.3 custom patch, and it just
doesn't seem to be the same as I remember back when I was first trying to figure
the scaling of media and container objects.  Fact is I had set my mind on this
kind of inverse scaling thing because I had seen it work out okay before.

If you could post to the povray.general newsgroup you will get a wider audience
there.  Some other people could help with it possibly.

Bob

"Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
news:38925821@news.povray.org...
| Thanks, but it didn't work.  Although this has solved the problem of the
| media appearing completely white, now it can not be seen at all.
|
| -Chris-
|
| > object { ContainerObject // scale 1000 here? media scale effect not
| present.
| >  material {
| >   texture { pigment { rgbf 1 } }
| >    interior { media {
| >                             scattering { 1, 1 }
| >                              density { 1 }
| >                             scale <.001,.001,.001> // opposed scale of
| object
| > scale
| >                             }
| >                 }
| >     }
| >  // object scale.  If <.001,.001,.001> here then 1000 X in media.
| >  scale <1000,1000,1000>
| > }
| >
| >
| > This way should do okay.  You're scaling the media then to counter object
| > resize.  When the object size starts off large the media isn't affected by
| that
| > scaling, ie. 'object { ContainerObject scale <1000,1000,1000>' etc. though
| the
| > texture pattern and all isn't fit to it in a unit anymore so scaling at
| the end
| > is usually done, although the scaling counter-effect solution doesn't need
| to be
| > used in this way if the container is already large (or small) before media
| is
| > applied.
| > Hope this solves it for you now.
| >
| > Bob
| >
| > "Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
| > news:388b5ddf@news.povray.org...
| > |
| > | Bob Hughes <omn### [at] hotmailcom?subject=PoV-News:> wrote in message
| > | news:388af1c9@news.povray.org...
| > | > You always have to oppose scale for media when scaling the object it's
| in.
| > | If
| > | > the scaling of the container object is first it isn't such a problem
| (?),
| > | if scaled after the media is in place then it is.
| > |
| > | What?  Do you mean scaling the entire texture w/ media or just the media
| or
| > | just the density or just the....etc.?
| > |
| > | > If the object is scale
| > | > <100,50,10> for example (at the end of the entire object statement)
| then
| > | go back
| > | > into the media statement and use a scale <1/100,1/50,1/10> to correct
| for
| > | the
| > | > increase in media density, etc.  Opposite true too.
| > |
| > | I scaled the object to <1000, 1000, 1000> but when I added a
| transformation
| > | to the density of <.001, .001, .001> the media disappeared completely.
| > | I think I understand your concept but I'm not quite sure what I'm
| supposed
| > | to be transforming.
| > |
| > | >
| > | > Bob
| > | >
| > | > "Chris Spencer" <chr### [at] bluelectrodecom> wrote in message
| > | > news:388a6470@news.povray.org...
| > | > | I have a problem...
| > | > |
| > | > | I've surrounded a sphere with media which isn't taking kindly to
| being
| > | > | scaled.  The model is a union of earth and a sphere of media
| surrounding
| > | it,
| > | > | simulating atmosphere.  When I try to scale this union the media
| becomes
| > | > | increasingly whiter and brighter until the image map of earth isn't
| > | visible.
| > | > |
| > | > | Is there a reason why this is happening?  Is there a way to fix
| this?
| > | > |
| > | > |  Thanks,
| > | > | -Chris-
| > | > |
| > | > |
| > | > |
| > | >
| > | >
| > |
| > |  Thanks,
| > | -Chris-
| > |
| > |
| >
| >
|
|
|

Post a reply to this message