Aurora Borealis effect?

[johnny_riptide]

Try using a particle system. Then, add motion blur to the particles. Maybe bind the particles to a Wind Space warp to get the particles to sway.

I don't know....there's a lot of ways to do things, but this is where I would probably start.

[sirius]

could give that a try but i fear particles are a lot slower than videopost, especially when you need massive amounts...so would prefer a post solution.
sirius

[Fede]

Hi

Not sure in what way you will be using your piece, but i would add that in post.

It will be much easier as you can see straight away what it's doing and have more feedback controll. Combustion would be great for this as it has some particle systems and gradients which are easy to animate.

If you don't have access to that look at using the inferno section of the video post for the glow and use a gradient which can be animated.

Or maybe, use a fire space warp and change the colors to the ones you need. not sure if you can use a gradient for that though.

I know i did not give a solution but hopefully i gave you an idea of another way to do it.

Later.

[Fozzie]

Check out the Pandora plugin from Digimation as it allows you to emit particles from a spline shape and it also contains a a new material that lets you control some values based on the life of the particles. Its very cool and you could probably do a very good Borealis effect.

Foz

[BrandonD]

Hmm, actually I'd just do this with an animated spline that's extruded (sort of like a ribbon). Then texture it with a Gradient Ramp and some animated Noise (stretched along one axis of course).

[sirius]

the particle plugins sound nice, but still i fear them slowing down everything.
I would have a look with combustion, but i am not very proficient with that. Is it possible to have particle emitters based on g-buffer object id inside combustion?

For now i am trying to do it with the suggestion of Brandon, which is for sure the most simple one, and maybe the fastest.
However i am still missing the volume aspect, it stays to much a plane.
I am wondering if there is something like a volume blur, of which the amount can be mapped to the object? ....that would be a wish!
And does a good videopost blur exist(dependant on distance, object id, and blurring behind?
:rolleyes:

[ErickG]

If you have the resources and have to have a volume effect than Afterburn is your best bet. You might be able to fake it with a volume and a gradient texture.

I would not go through this unless you plan on flying into them. A post effect done in combustion or AfterEffects will work just fine if you are just looking up into the sky with a small amount of camera motion.

That's my 2cents worth.

-Erick

[Paul L. Ming]

Hiya.

Animation, or still? If animation, any of the suggestions so far might work. The tricky part would be having the "birth and death" effects of them, as well as...hmmm, how do I put this...uh...hmm. Ok, when you are looking at the "northern lights" you can see them changing, but you can't see where they changed. It's a really wierd effect. You know they've changed color, brightness, direction, speed, etc., but they all blend together in a wierd sort of way. Sorry, that's no help. Animation of them would be "tricky". For me, I'd just go out my back yard and film them one night. :)

Still...I'd suggest going with a still picture. :) Honestly, why try and duplicate it unless you need something to interact with it? Mind you, we still don't know exactly what "it" is (the aurora borealis). A good, high-res picture slapped on a grid, a few tweaks with some particle/smoke-like glowing effects and you're done. :)

I would go out back and snap a few pictures, but: A) no decent digital camera; and B) it's overcast tonight. :(

Still picture, smoke particles, glow. Might work... ;)

For reference, here's a site with pictures for you to gander at (and a link or two you can get from there). :)

http://www.ptialaska.net/~hutch/aurora.html

[sirius]

Hi, you are absolutely right that a real aurora would be very difficult to simulate. Especially if you cant observe them in real-life. I am envious, you are over there on the first row of the aurora theatre. :)
However i want to animate an effect which looks like an aurora, not necesssarily an exact reproduction.
In the aurora "clouds" will appear text, signs which integrate and desintegrate more or less like the aurora effect itself.

If you know a website with movies of aurora, that would be of great help. Most pictures are taken with with large exposure times, so its difficult to judge how they look in reality.

On this webpage i found many links to aurora pictures and info: http://www.northernlightsnome.homestead.com/Links.html

sirius

[xgastudios]

Greetings,

Here is a great web site the I used for reference when I had to create auroras for our real-time StarRider planetarium show.

http://www.phys.ucalgary.ca/~trondsen/TheAurora/

here are a few others

http://www.exploratorium.edu/learning_studio/auroras/photo.html


http://northernlightsnome.homestead.com/index.html

Enjoy

Matt

[sirius]

:thumbsup: Thanks all.:thumbsup:


especially the tecnical report on scientific simulation of auroras at http://www.phys.ucalgary.ca/~trondsen/TheAurora/ is of great help, giving much info on the actual visible behaviour of auroras and how to simulate these phenomenons.

mr. XGAstudios, if i may ask, what did you use to create them for the realtime planetarium?

sirius

[xgastudios]

Glad I could help, anytime.......

I started the model out in 3dsmax v 4 and exported it to Multigen Creator v 2.2.1 with E&S extensions. From there I was able to set parameters of movement and alpha then export it as a GRM, a proprietary E&S model format. The model was then loaded onto our ESIG (E&S Image Generator) and displayed in our StarRider theater.

:buttrock:

Matt

[googlo]

I would use a animated bitmap, like a squiggley s (the s white, the rest black) as a projection map in a free light and then just attenuate the fog and light colors to get gradiations of color. If you want to animate striations within the light, just modify the animated bitmap to contain black noise or evolving dark spots over the white squiggley, that way you'll get shafts of light being animated as they project through.

You can make the animated projection map with noise first by animating a squiggly spline in an orthographic view and rendering it out for use as the animated bitmap for the lights projection map.

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