KalleK <kal### [at] gmxde> wrote:

> Hi Goeff!

>> (the clouds on a skysphere don't flatten
>> towards the horizon, so it looked really fake)

> You can flatten them by attaching a scale like <1,.2,1> to the
> sky_sphere's pigment.
> But you shouldn't look upwards then. There are strange circles of
> clouds above you...

> Just an idea

> Nice picture, btw. And I can't imagine how you did it - not using the
> portal_pigment.

Nope, though the pp discussion made me want to post this, since people were
wondering what sorts of things it could be good for.  It does
require Megapov.

Geoff

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Excellent!  Summer is a bit dark.  On the other hand, a bright summer day
probably isn't as bright as a bright winter day with the snow reflections.  How
did you do the brick wall/arch?

Cris Williams

Geoff Wedig wrote:

> Well, I just saw the thread on Chris Huff's portal patch, so I thought I'd
> post this.  This is one type of image that would be much easier to do with
> such a patch, I'd imagine (though the patch doesn't allow light to pass
> through)  It would certainly be faster than my method.
>
> Speaking of which, my method isn't a camera trick.  I can place the camera
> wherever I like and the scene doesn't go funky, up to and including the other
> side of the doorway.
>
> So what do folks think so far?  I'd like to increase the realism if possible,
> because, somewhat counterintuitively, the more real I can get this, the less
> real it'll seem.
>
> Geoff
>
>   ------------------------------------------------------------------------
>  [Image]

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Actually it should get lighter toward the horizon. Lightness toward the sun
would be more of a 'cone' or lens-flare effect. The air and dust particles
in the air does actually give a slight 'fog' effect. That's why mountains
seem bluish in the distance.

Nekar

> It currently fades to a darker blue towards the horizon, but I must admit,
I
> couldn't remember which way it went. It should also be brighter
'sunwards',
> but I'm not certain how to accomplish that.
>
> Geoff
>
>

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Cris Williams <wor### [at] netscapenet> wrote:

> Excellent!  Summer is a bit dark.  On the other hand, a bright summer day
> probably isn't as bright as a bright winter day with the snow reflections.  How
> did you do the brick wall/arch?

Yeah, it's difficult to make the summer seem brighter, since the winter is
mostly white and light grey, so I settled for making it a lot more colorful.

The wall is from code that I designed called the ISW (Iso-stone Wall). 
Originally, it started out as a port of the mur.inc to iso-surfaces, but I
found that mur.inc wasn't adequate for what I wanted to do.  So I rewrote it
from the ground up.  I built a lot more logic into the laying of stones, and
included a bunch of macros to allow me to make things like towers and tubes,
each with variable radius.  These are done by permutation functions to the
isosurface function.  I want to add a spherical and disc like as well, but
that's not done yet.  The arch is just a very short (one block long) half tube.

Incidentally, it's not just for stone.  I've made some really nice hardwood
floors with it and the isowood.inc just by re-defining a bunch of macros.

At some point, I need to write up a quick doc for it and then I'll release
it.  The code is pretty clean, but it's tricky to see what needs doing to
get the right effect without some guidance.

Geoff

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At some point, I need to write up a quick doc for it and then I'll release
it.  The code is pretty clean, but it's tricky to see what needs doing to
get the right effect without some guidance.

Geoff
*******
Great . . .
  Those stones are what draw me to this pic . . .
   Looking forward (my fav direction ;) to taking a look at it.
Thanks,
Y

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In article <3A9### [at] darwincwruedu>, spo### [at] corecom wrote:

> Well, I just saw the thread on Chris Huff's portal patch, so I 
> thought I'd post this.  This is one type of image that would be much 
> easier to do with such a patch, I'd imagine (though the patch doesn't 
> allow light to pass through) 

Actually, it would be possible to simulate the effect of light shining 
through the portal...just create another copy of the lights you want to 
shine through the portal, transform them to where they would be on the 
"other side" when seen through the portal, and use the projected_through 
feature to make them shine through the portal.
This wouldn't be perfect...a shadow on the other side of the portal 
wouldn't pass through it. It would work in most situations, though.


> It would certainly be faster than my method.

What was your method?

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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Chris Huff <chr### [at] maccom> wrote:

> In article <3A9### [at] darwincwruedu>, spo### [at] corecom wrote:

>> Well, I just saw the thread on Chris Huff's portal patch, so I 
>> thought I'd post this.  This is one type of image that would be much 
>> easier to do with such a patch, I'd imagine (though the patch doesn't 
>> allow light to pass through) 

> Actually, it would be possible to simulate the effect of light shining 
> through the portal...just create another copy of the lights you want to 
> shine through the portal, transform them to where they would be on the 
> "other side" when seen through the portal, and use the projected_through 
> feature to make them shine through the portal.
> This wouldn't be perfect...a shadow on the other side of the portal 
> wouldn't pass through it. It would work in most situations, though.

Is the projected_through available now?  Last I heard, portals only did a
pigment, no light through the portal or photons or such.  Has it progressed,
then?


>> It would certainly be faster than my method.

> What was your method?

I was waiting for someone to ask. ;).  I created both scenes, then cut them
in half.  One half is set no_image and scaled <1,-1,1> (I use z as up.  More
intuitive for me) while the other is no_reflection.  Then I set up a perfect
mirror with a hole in it at the right place, and use light groups to get the
reflections lights to work right.

Only problem is that this makes essentially the entire picture one big
intersection.  Bounding goes out the window, and with all those isosurface
stone blocks, it slows to a crawl.  I've gotten away with a few things (the
tree, for instance doesn't pass the invisible wall so doesn't need to be
intersected), but for the most part, things get slow really quickly.

The advantage of doing all this is being able to set the camera up wherever
is convenient, and getting easy light pass through.  One disadvantage that I
noticed last night is that I can't use focal blur (post process), because
only the summer side gets blurred.  The winter side is all at the mirror
distance, rather than its 'true' distance, so doesn't get appropriately
blurred.  On the other hand, a portal would have the opposite problem, with
only the winter side blurring.

Geoff

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In article <3a955c4d@news.povray.org>, Geoff Wedig 
<wed### [at] darwinepbicwruedu> wrote:

> Is the projected_through available now? 

It's been around since the Superpatch days, I think.


> Last I heard, portals only did a pigment, no light through the portal 
> or photons or such.  Has it progressed, then?

No, the projected_through feature has nothing to do with the portal 
patch, it is a light_source feature that allows you to "project" light 
through an object, making light shine through the object.


> One disadvantage that I noticed last night is that I can't use focal 
> blur (post process), because only the summer side gets blurred.  The 
> winter side is all at the mirror distance, rather than its 'true' 
> distance, so doesn't get appropriately blurred.  On the other hand, a 
> portal would have the opposite problem, with only the winter side 
> blurring.

The ordinary focal blur should work fine, though...it would just make 
your scene even slower.

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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Chris Huff <chr### [at] maccom> wrote:

> In article <3a955c4d@news.povray.org>, Geoff Wedig 
> <wed### [at] darwinepbicwruedu> wrote:

>> Is the projected_through available now? 

> It's been around since the Superpatch days, I think.


>> Last I heard, portals only did a pigment, no light through the portal 
>> or photons or such.  Has it progressed, then?

> No, the projected_through feature has nothing to do with the portal 
> patch, it is a light_source feature that allows you to "project" light 
> through an object, making light shine through the object.

Ok, now I'm confused.  Does that mean light only exists after the object,
that the light rays don't exist in the space between light and object, but
come from the object?


>> One disadvantage that I noticed last night is that I can't use focal 
>> blur (post process), because only the summer side gets blurred.  The 
>> winter side is all at the mirror distance, rather than its 'true' 
>> distance, so doesn't get appropriately blurred.  On the other hand, a 
>> portal would have the opposite problem, with only the winter side 
>> blurring.

> The ordinary focal blur should work fine, though...it would just make 
> your scene even slower.

Yeah, and I've found that the sampling menthods don't give good results,
IMO.  But maybe for a final render with *lots* of samples...

Geoff

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In article <3a956b79@news.povray.org>, Geoff Wedig 
<wed### [at] darwinepbicwruedu> wrote:

> Ok, now I'm confused.  Does that mean light only exists after the object,
> that the light rays don't exist in the space between light and object, but
> come from the object?

Exactly. All areas that would be in the shadow of the projected_through 
object are illuminated. You would just use a copy of the portal object 
as the projected_through object, and transform copies of the necessary 
light_sources to appear through the portal object as if they were on the 
other end.


> > The ordinary focal blur should work fine, though...it would just make 
> > your scene even slower.
> 
> Yeah, and I've found that the sampling menthods don't give good results,
> IMO.  But maybe for a final render with *lots* of samples...

You can almost eliminate the grainyness if you use the right settings, 
but it is slow...

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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