I now have some proper smoke and underwater lava!

The only things I can see that need more work now are:
-steam: many people suggested various points for steam to be appearing, and 
I totally agree.
-colours: it's all gone a bit grey in this version, I want to get some black 
in the smoke and volcanic rocks.
-more colours!: that water just looks wrong IMO, should be very cloudy, 
darker, less green, and with steam bubbling round the lava.
-background: those conical mountains will change into realistic ones 
eventually I promise, and the sky colour's maybe too bright

But I'm sure you folks can think of other things to improve!

Your comments thus far have helped immensely! So keep them coming :)

-- 
Tek
http://evilsuperbrain.com

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Tek wrote:
> I now have some proper smoke and underwater lava!
> 

great improvment since first version ... wow.


> The only things I can see that need more work now are:
> -steam: many people suggested various points for steam to be appearing, and 
> I totally agree.

I see a small problem by adding steam colums where the lava hits the water. Your 
smoke colum implies a wind drift coming from left-behind. So the steam colum 
would also drift to the right-front and would cover parts of the most 
interessting elements in your scene.

> -colours: it's all gone a bit grey in this version, I want to get some black 
> in the smoke and volcanic rocks.
> -more colours!: that water just looks wrong IMO, should be very cloudy, 
> darker, less green, and with steam bubbling round the lava.

The underwater part looks just to calm. As I renember right, there won`t be much 
bubbles as they tend to implode in the cold water (making this cracking noise). 
But due to the heat you get some kind of striation (Schlierenbildung ???), 
meaning the large temperature gradient causes a field of water with variable IOR 
surrounding the lava. As POV can't deal with variable IOR right now, I don't 
know a quick solution; maybe a series of consecutive isocentric transparent 
spheres with slightly turbulated normals (and a different IOR to the water 
container of cause) could be used to fake it.

... dave

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"David El Tom" <dav### [at] t-onlinede> wrote in message 
news:43e309b1@news.povray.org...
> I see a small problem by adding steam colums where the lava hits the 
> water. Your smoke colum implies a wind drift coming from left-behind. So 
> the steam colum would also drift to the right-front and would cover parts 
> of the most interessting elements in your scene.

Good point, I hadn't noticed that but you're right. However I'm going to 
keep the steam pretty subtle so I don't think it'll be a problem

>> -colours: it's all gone a bit grey in this version, I want to get some 
>> black in the smoke and volcanic rocks.
>> -more colours!: that water just looks wrong IMO, should be very cloudy, 
>> darker, less green, and with steam bubbling round the lava.
>
> The underwater part looks just to calm. As I renember right, there won`t 
> be much bubbles as they tend to implode in the cold water (making this 
> cracking noise).

Take a look at the video on this page: 
http://www.pmel.noaa.gov/vents/nemo/explorer/concepts/pillows.html
Definitely bubbles, but they're very small and mostly just add an uneven 
cloudiness to the water except right next to the hottest bit where the 
bubbles are largest (though still tiny).

> But due to the heat you get some kind of striation (Schlierenbildung ???), 
> meaning the large temperature gradient causes a field of water with 
> variable IOR surrounding the lava.

Well heat ripples aren't so vital, unless it's an animation. But anyway it's 
a good idea I'll see how it looks if I cheat with a simple change in IOR 
along a bumpy surface.

--
Tek

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Tek wrote:

> I now have some proper smoke and underwater lava!
> 
> The only things I can see that need more work now are:
> -steam: many people suggested various points for steam to be appearing,
> and I totally agree.
> -colours: it's all gone a bit grey in this version, I want to get some
> black in the smoke and volcanic rocks.
> -more colours!: that water just looks wrong IMO, should be very cloudy,
> darker, less green, and with steam bubbling round the lava.
> -background: those conical mountains will change into realistic ones
> eventually I promise, and the sky colour's maybe too bright
> 
> But I'm sure you folks can think of other things to improve!
> 
> Your comments thus far have helped immensely! So keep them coming :)
> 

Neat, very very neat.

A few remarks ( off course :) )

The boulders/rocks thrown out of the vent are too evenly shaped. They can
vary from fist size to house size.
No impact dust where the boulders come down.
You'll need some sort of steam column where the lava meets the see.

Underwater has come a long way but it looks too quiet, almost tranquil.
Now I don't get a sense of the brute forces that are at work there. (but
don't ask me how to do that :) )

Keep up the good work
-- 
Ger

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Tek wrote:
> [...]
> 
> But I'm sure you folks can think of other things to improve!

Note these are aspects to improve realism - you might not intend to make 
this most realistic of course.

The Lava: it should always flow downhill - in your case it goes uphill 
in some places.  Also it is somewhat too dark for smoothly flowing lava 
(the dark red one at the water edge would hardly flow any more).  It is 
reasonable to make the lava as bright as the flying one at the top of 
the mountain.

The mountains: Like in terragen images you have a fine structured 
visible surface contrasting with smooth edges.  This probably is a 
result of using bump mapping on a relatively low detail terrain.  This 
makes it look a bit like a theatre mountain made of painted styrofoam.

The 'pyrotechnical effects' are great but does the dust cast shadows on 
itself and the mountains?

Christoph

-- 
POV-Ray tutorials, include files, Landscape of the week:
http://www.imagico.de/ (Last updated 31 Oct. 2005)
MegaPOV with mechanics simulation: http://megapov.inetart.net/

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This is starting to look really good especially the smoke/fire effect. I was
thinking of doing a snow covered volcano scene myself for this round of
IRTC but am glad I didn't as my attempts were nowhere near as good as this.
Congrats on winning the round before last BTW that was a great image. As
this is still WIP I guess you may be planning to change the following (and
I think these may  have been mentioned in previous posts) but I think the
rocks at the front need to look a bit more like they are glowing and they
would be having an effect on the water, the lava flow at the bottom of the
volcano would probably not be so close to the snow (without melting it). I
also agree with you that the image needs a bit more colour (not sure where
or how this can be added though)

I hope you post the source with this one as I would like to steal (I mean
learn from..) your smoke effect.

Great work.

Sean

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"Tek" <tek### [at] evilsuperbraincom> wrote:
> -colours: it's all gone a bit grey in this version, I want to get some black
> in the smoke and volcanic rocks.
I quite like the grey, at least for the rocks - looks more volcanic.

I can only think of two other comments, although they're quite minor.
Firstly, I think the lava fountain is a bit regular - too much like a point
source; maybe having several sources together would give it a little more
volume. Secondly, the flowing lava (and the underwater lava) should perhaps
glow a little brighter (although maybe the brightness of the river should
decrease with distance?).

Fantastic looking image, though, especially the above/below water split -
this is going to be a classic!

Bill

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Great improvements!
Something that bothers me a little: the lava underwater looks a little bit
too much like separate blobs of matter. I think they should be more
interconnected, forming a bumpy flow over overlapping blobs, but well-welded
together within the flow. A few more bright burstings, more in the
background would also improve that part of the scene, while increasing
perhaps somewhat the murkiness of the water.

Thomas

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"Tek" <tek### [at] evilsuperbraincom> wrote in message
news:43e300e2@news.povray.org...
> I now have some proper smoke and underwater lava!
>

Very nice.

The flowing lava should be a bit brighter. See here (volcano in iceland)
http://antwrp.gsfc.nasa.gov/apod/ap060129.html

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This is coming along quite nicely!  Other than things that other people 
have mentioned, there are a couple of things that strike me.  First I 
would guess that there's be some snow melt bordering the lava flow. 
Currently it seems like the lava borders the snow directly and I think 
this is what makes the lava flow look "pasted on" to me.  I looked for 
an image to confirm this, but this was the best I found, and it's not a 
particularly clear picture of it:

http://www.spring.net/marci/Public/Hawaii/LavaOnSnow.jpg

It's also possible that the scene could benefit from some haze.  Other 
than the smoke plume itself, the air is very clear.  Part of this I 
imagine is because it gives a really nice contrast in the upper part of 
the image, but perhaps some small amount of haze could still help 
without destroying this effect.

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