cygnus@vax1.acs.udel.EDU (Marc Cygnus) (09/03/89)
I'm working on an animation sequence (part of) which involves a nuclear
groundburst. I don't want just a `mushroom cloud' -- I need to animate the
entire burst from initial fireball through the characteristic `mushroom'.
I don't need to include receeding clouds, though it would add a nice touch.
Has anyone attempted modelling such physical events? My requirements are fairly
lax; after all, the animation is not a scientific visualisation of burst
mechanics, but rather a playful `let's-see-what-the-machine-can-do' project
laced with humour. I _do_ want the thing to look as realistic as is feasible,
though.
The hardware involved is an HP Turbo SRX (350, I believe). Also, since the
animation will be frame-edited to a VTR, the algorithm(s) may consume any
reasonable amount of time. Anything up to 400-450 CPU hours will be fine
(assuming 60 - 80 seconds of video).
I had originally planned to obtain some footage of groundbursts and digitise
burst outlines, using the 2D outline as the cross-sectional basis of a spline
surface. To give the burst a more realistic appearance, some sort of repeatable
bump-mapping scheme could be applied to the surface, or the actual surface
control points could be perturbed in a repeatable, controlled fashion. And, of
course, lighting would have to be manipulated appropriately (but that's not the
big problem).
If anyone has a better suggestion, or (*much* better yet) has actually gone
and _done_ something similar, please email me (and many thanks in advance!).
If anything brilliant or extremely elegant passes my way (and if readers wish)
I will summarise.
-marcus-
--
-----------------------------------------------------------------------------
"Opinions expressed above are not necessarily those of anyone in particular."
`...but do YOU own a | ARPA: cygnus@vax1.acs.udel.edu
homemade 6ft Tesla?' | UUCP: {yourpick}!cfg!udel!udccvax1!cygnuseugene@eos.UUCP (Eugene Miya) (09/05/89)
In article <4295@udccvax1.acs.udel.EDU> cygnus@vax1.acs.udel.EDU (Marc Cygnus) writes: >I'm working on an animation sequence (part of) which involves a nuclear >groundburst. I don't want just a `mushroom cloud' -- I need to animate the >entire burst from initial fireball through the characteristic `mushroom'. >I don't need to include receeding clouds, though it would add a nice touch. > >Has anyone attempted modelling such physical events? My requirements are >fairly lax; after all, the animation is not a scientific visualisation of >burst mechanics, but rather a playful `let's-see-what-the-machine-can-do' >project laced with humour. I _do_ want the thing to look as realistic as >is feasible, though. It's not clear to me what you are trying to do. It's like asking for a flight simulation without the equations and science behind flight. Burst mechanics are burst mechanics. I post this note because I'm beginning to see a lot of this "show the science without trying to understanding it." We see a lot of this with fluid dynamics research, and I am not a dynamicist, but I make an effort. This trend away from science is somewhat disturbing. Back to fire balls. I will assure that such modeling has been done for decades. This was what MAGI was set up do, not generate pretty CG. All the National Weapons Labs have been working on it. All classified. The computer companies who supply hardware to these Labs (trying naming one not) do little "show you what out H/W can do" demos specifically for their "Federal" clients. You can certainly ask around, but most of these companies will deny the existence of such "dirty" work. They do this by hiring ex-Lab employees in "cleared" divisions. They then generate client specific information and make sales. > Summary of texture-mapping and outlining removed for brevity. (Roto-scoping) Go with this. It is simple and non-classified. Or employ a good artist. 8) The Distribution: field on the header has been modified so as not to violate Information Export laws. Another gross generalization from --eugene miya, NASA Ames Research Center, eugene@aurora.arc.nasa.gov resident cynic at the Rock of Ages Home for Retired Hackers: "You trust the `reply' command with all those different mailers out there?" "If my mail does not reach you, please accept my apology." {ncar,decwrl,hplabs,uunet}!ames!eugene Live free or die.