POV-Ray : Newsgroups : povray.binaries.animations : roiling fire cloud WIP 1 : roiling fire cloud WIP 1 Server Time: 18 Jan 2019 00:59:39 GMT
  roiling fire cloud WIP 1  
From: Kenneth
Date: 21 Jun 2017 22:50:02
An 'initial proof-of-concept' for a roiling gasoline fire or explosion. Included
is a representative image from the 'net to compare my trial against.

Currently, I'm using individual media spheres that overlap somewhat, with  just
emission and absorption medias (and only 'half a donut's worth' of spheres, for
testing.) I toyed with the idea of using a large torus object instead (with a
toroidal warp of the media); but using individual spheres gives better
'erratic/random' control of the overall roiling fire look, and I can tweak the
micro-details more easily.

(For those interested, here's a video and an academic paper I came across,
describing a modern CGI/mathematical 'conceptual' approach to creating this type
of thing. )

https://www.youtube.com/watch?v=vBLZ4jja8No

http://www.cs.cornell.edu/~tedkim/wturb/

For my own MUCH simpler test, there still remains a lot of stuff to work out
(and all this just for the 'top' of the roiling fire!):

* adding more spheres!

* more intense fire colors

* making the individual 'fires' in the spheres random-looking, and maybe with
different rotation speeds. (Currently, it's the same single sphere, duplicated.)
I'll probably turn the code into a macro, to make it easier to work with for
multiple different spheres.

* making the yellow-to-red-to-black  color-gradations 'sharper' and less
'blurry' looking-- a matter of tweaking the color-maps

* addind scattering media, to get self-shadowing of the gray/black smoke from
the light source(s). That's currently missing (I may have to fade out both the
emission and absorption medias along the way, somewhat.) As a practical matter,
the initial fire doesn't need self-shadowing (real  fire is probably brighter
than any incoming light source.) But that needs to change as the fire 'does
down' and turns into smoke.

* thinning (and 'graying') of some of the smoke as it turns black, with a more
'wispy' nature

* a slow-down of the rotational roiling as the cloud progresses upwards

* expanding the size of the spheres as they turn black/gray.


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Attachments:
Download 'roiling fire cloud exp 2.mp4.mpg' (3223 KB)

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