This is what happens when you're up too late, kind of bored, and you
look at your lava lamp and go "Hey, I wonder if....."

I need some suggestions on this one, it looks decent, but not quite
right yet.

Post a reply to this message

Attachments:
Download 'lavalamp_1.jpg' (34 KB)

Preview of image 'lavalamp_1.jpg'

It really looks good. I think the "not quite right" is because it looks like
it is "off": The light looks like it comes from outside the lamp, not from
the lamp (from its bottom part) itself...
Maybe that is because the shading of the blobs is wrong? They don't look
like being lighted from below. The also miss the "glowing" quality of the
blobs in my lavalamp.

Johannes.

Scott McDonald wrote in message <36CCFF7C.8AD69922@metrolink.com>...
>This is what happens when you're up too late, kind of bored, and you
>look at your lava lamp and go "Hey, I wonder if....."
>
>I need some suggestions on this one, it looks decent, but not quite
>right yet.

Post a reply to this message

Johannes Hubert wrote:
> 
> It really looks good. I think the "not quite right" is because it looks like
> it is "off": The light looks like it comes from outside the lamp, not from
> the lamp (from its bottom part) itself...
> Maybe that is because the shading of the blobs is wrong? They don't look
> like being lighted from below. The also miss the "glowing" quality of the
> blobs in my lavalamp.
> 
> Johannes.

I have pretty much the same impression. Of the 4 or 5 lava lamps I
have modeled, yes it's a reoccurring retro 60's thing with me, I have
buried a light source in the bottom just to illuminate the base
of the lamp and the glass where they meet. I rely on some diffuse
value for the blobs but more heavily on the ambient component. If
the ambient is high enuogh the colors of the blobs add to the glowing
effect. I have tried animating them but I can never get a nonrepeating
pattern to the blobs and still have them stay in the container.

-- 
Ken Tyler

mailto://tylereng@pacbell.net

Post a reply to this message

re: Ken & Johannes' suggestions re:ambient on blobs.

great idea, i'll give it a go tonight when i get home - I already have a
light in the bottom of the lamp, i'll play with the textures on the
blobs next.


thanks a lot.
-- 
+----------------------------------------------------------------------+
|Colin Scott McDonald                                  Metro Link, Inc.|
|                     veni, vici, in dominum redirre                   |
|sco### [at] metrolinkcom                                  www.metrolink.com|
+----------------------------------------------------------------------+

Post a reply to this message

> I have tried animating them but I can never get a nonrepeating
> pattern to the blobs and still have them stay in the container.

I once got started on a demo with this, but never got the hang of the
math. It must be something depending on warmth and cooling off, at a
certain point the warm fluids will break the gravity, and then draw
upwards and cool off to fall down... any math genious around who can
tell me what formulae to work on??



-- 
//Spider 
( spi### [at] bahnhofse ) [ http://www.bahnhof.se/~spider/ ]
#declare life = rand(seed(42))*sqrt(-1);

Post a reply to this message

Spider wrote:
> 
> > I have tried animating them but I can never get a nonrepeating
> > pattern to the blobs and still have them stay in the container.
> 
> I once got started on a demo with this, but never got the hang of the
> math. It must be something depending on warmth and cooling off, at a
> certain point the warm fluids will break the gravity, and then draw
> upwards and cool off to fall down... any math genious around who can
> tell me what formulae to work on??> 

A high sloping sine wave with a narrow duration might pull it of
but you would have to figure out how to recycle it back through
the loop. It's the intereaction with the other blobsd that was
really giving me problems. In most cases a blob in the real lamp
just slides past those that are of a differnt temperature. A blob
in the pov world likes to alter it's shape when it comes into contact
with other blobs.

-- 
Ken Tyler

mailto://tylereng@pacbell.net

Post a reply to this message

Very groovy.

Speaking of lava lamps, I once thought of programming a lava lamp screen
saver. I only wanted blobs moving in 2D but I could never find good
resources on how to program this. Does anyone know of any sites that
explain blobs in 2D well?

-- 
Chris Maryan
mailto:cma### [at] geocitiescom
***
Will work for cash.
***
Email me if you are interested in donating
to the Chris Maryan needs money fund.
We will also accept donations to the Chris
needs a Pentium II or SGI workstation 
fund and the Chris needs a car fund.

Post a reply to this message

Cool lamp! Nice static display.  A couple of things, tho.....

If the lamp's heated up (since blobs are active, I'd say this is a good
bet) then
the low-viscosity liquid (the "water") will have expanded until the
level is
up underneath the black top cap (At least on all the lamps I own).

Also, is the "water" clear?  It appears to be the same color as the
"lava". 
In general, the two liquids are contrasting colors (the clear "water"
and 
cobalt blue "lava" is cool, as is the classic yellow "water" and red
"lava")

As far as dynamic displays go, check the Navier-Stokes equations, then 
immisicble flow equations, and forced convective flow. <grin>  I hope
you
like non-linear differential equations.

(Seriously, it's an experiment in HEAVY hydrodynamics, approximatley as 
difficult as air flow through a supersonic jet engine. Good luck -- I've
toyed with it before....)


Again, cool pic!


Tim Glover
tgl### [at] nettallycom  
 


Scott McDonald wrote:
> 
> This is what happens when you're up too late, kind of bored, and you
> look at your lava lamp and go "Hey, I wonder if....."
> 
> I need some suggestions on this one, it looks decent, but not quite
> right yet.
> 
>     ---------------------------------------------------------------
>  [Image]

Post a reply to this message

Tim Glover wrote:
> 
> Cool lamp! Nice static display.  A couple of things, tho.....
> 
> If the lamp's heated up (since blobs are active, I'd say this is a good
> bet) then
> the low-viscosity liquid (the "water") will have expanded until the
> level is
> up underneath the black top cap (At least on all the lamps I own).

mine looks like this one when its on.  
 
> Also, is the "water" clear?  It appears to be the same color as the
> "lava".
> In general, the two liquids are contrasting colors (the clear "water"
> and
> cobalt blue "lava" is cool, as is the classic yellow "water" and red
> "lava")

Mine has blue water and white blobs, and thats what textures i've
assigned to the rendering, but i agree the blobs look the same colour. 
<sigh> ;)

thanks

-- 
+----------------------------------------------------------------------+
|Colin Scott McDonald                                  Metro Link, Inc.|
|                veni, vici, volo in dominum redirre                   |
|sco### [at] metrolinkcom                                  www.metrolink.com|
+----------------------------------------------------------------------+

Post a reply to this message

<begin personal bias>

Yech!  The blue "water"/white "lava" is the WORST combo they make. 
Downright ugly!

<end personal bias>


You probably need to fiddle with the filter/transparency values for 
the "water" then, since it doesn't seem to be passing the white 
through.

Tim G.

tgl### [at] nettallycom

In response to:

Scott McDonald wrote:

<snip>

> 
> Mine has blue water and white blobs, and thats what textures i've
> assigned to the rendering, but i agree the blobs look the same colour.
> <sigh> ;)
> 
> thanks
> 
> --
> +----------------------------------------------------------------------+
> |Colin Scott McDonald                                  Metro Link, Inc.|
> |                veni, vici, volo in dominum redirre                   |
> |sco### [at] metrolinkcom                                  www.metrolink.com|
> +----------------------------------------------------------------------+

Post a reply to this message