electric path

[Kris Rivel]

Any tips for creating an "electric path"?  I want to create a flow of electricity that is undulating along a set path...like a lighting or plasma ball effect but moving from object a to object b to object c, etc.  I'm having some success playing with some found plasma ball, electricity examples but just poking around in case anyone has done this before and has more tips to share.  Thanks.

Kris

[Joe Laffey]

Textures on one or two transparent tubes. Then add glow and such in the
post... That would be my first thought.

--
Joe Laffey | Visual Effects for Film and Video
LAFFEY Computer Imaging | -------------------------------------
St. Louis, MO | Show Reel http://LAFFEY.tv/?e23416
USA | -------------------------------------
. Since 1991 | -*- Digital Fusion Plugins -*-
--------------------------------------------------------------------------

[Juhani Karlsson]

Lightning or electricity kinda behave like l-systems.
You could maybe digg some ICE tree generator up and modify or add some logic to it. : )

- Juhani

2011/9/26 Joe Laffey <j...@laffey.tv>

[Alan Fregtman]

In relatively straight lines between objects, or literally along a curve path?

Sounds like a fun challenge. I'll try later when I get home. :)

[Kris Rivel]

well straight lines...like a chain of balls or something with electricity going from one to another...like an electrified fence.  I have no problem building one from A to B but creating a series via one tree is harder.  I suppose I can duplicate several systems but was hoping for something more streamlined.

Kris

[Marc-Andre Carbonneau]

Perhaps the solution is in here somewhere ;)

http://vimeo.com/21408099

[Kris Rivel]

Ha yeah..I have that..most likely will duplicate this several times.  Was just thinking of a way to maybe put an array of objects in vs. just two so it would be going from a to b to c to d, etc.

[Kris Rivel]

Oh and thanks Vincent for that! :-)

[Kris Rivel]

Wow...create strand from curves works really well actually..didn't think about that!

[Andy Moorer]

I've been doing lightning/electrical effects for the past few months. :) Mostly we needed pretty busy masses of electricity and lightning, so this is probably overkill but I might as well share what I can...

We needed a whole suite of lightning tools, for multiple shots on multiple commercials. In general we did a few different things - most of the lightning stuff is strands, either l-system or (slower but better looking) DLA structures. For most shots I used a (much more advanced  ) version of the DLA compound I made a year or so back, with the general structure generated and then frozen, and then turbulized while transparencies are run up and down the strands in the system...

"Crawling" electricity tends to run down the length of the electrical trail as opposed to the trail moving laterally, although often the tip will move along sharp edges etc. A few layers of turbulence on the strands is necessary even when when you see the electrical effect for just a few frames, even larger scale lightning bolts.

Our results are definitely superior to, say, the maya paint/fx plugins or 2d lightning effects like sapphire (both of which are l-system type approaches.) 

For a single point-to-point electrical effect, you can get a really nice look very quickly by simply turbulizing a strand (or a curve). The trick there is to use several layers of turbulence at different frequencies, and to clamp the turbulence so that you get a sharper, more stacatto movement as opposed to the jello-y soft feel you get from turbulence functions out-of-box.

We've found that while sapphire 2d lightning in the hands of a flame artist can look great, 3d electrical effects are often worth the extra effort - you percieve the parallax, and you can use the 3d information to cast light on surfaces, reflect, scar surfaces, make sparks and so on. Half of the realism comes from seating the effect in your scene with extra details like cast light from the electricity.

Cheers,

AM

[Kris Rivel]

Thanks Andy for the tips.  I think I'm having good results just using strands generated from a curve.  I'm electrifying a rectangular area and layering up some turbulence seems to be working nicely.

I can honestly say that if someone packaged up a few lighting/electric effects as models or scenes and sold them, I'd definitely buy them.  It comes up often and as you said, 2d approaches aren't always the best.  Would just be a great toolset to have shelved along with fire and fluid effects which we already have great tools for.

Kris

[Andy Moorer]

Once I get done with this gig (and sort out what I can release vs proprietary,) I will share out my personal toolkit for electrical stuff to the community. Least I can do. :)

If anyone is interested in comparing laplacian/DLA versus L-system style electricity and lightning, I believe a popular lightning plugin for the blender community is DLA, and based on the same papers I drew from. But much, much slower. The system I am using is AFAIK the fastest of it's kind out there, thanks both to ICE's set-crunching capability as well as a significant change I made to the basic algorithm which bypasses a lot of calculations.

Cheers,

Andy

[Kris Rivel]

Sounds hot..looking forward to it!

[Olivier Jeannel]

I'd be currious on the DLA method.
On my last project I've been playing with turbulized strand, all sorts of ways, to make accelerated plant growing effect, with goals. looked quite electrical in the end, but cool enough. Some shot invoved duplicated branches and those one were done "manualy" (ClonePoint).
Would have loved to see (simple) examples of self generating branches. I guess you must create some kind of loops.

Cheers,

Olivier

[Andy Moorer]

Right, it's really a very simple iterative method at heart. There's a compound on andy.moonbase.net which was the first dla I made a long while back (I think it's available but private, been meaning to change that sorry.) I think a couple of other xsi-ice guys have made similar compounds.

The basic idea is that of iteratively adding points to a "seed" location(s). Start with a point, then generate a point at a random location (which is a rough goal), then move it towards the seed point until it's a certain distance from it. Then consider both as "seeds" and repeat. With many iterations you end up with branching structures with similar patterns at different scales, a sort of primitive fractal.

Depending on the exact method you use to generate random points and how you determine their final relationship to a "seed" you can get various looks, from bolt lightning to road networks, rivers or fijords.

One of the first papers I read on the subject, and one of the best, is here: http://gamma.cs.unc.edu/FRAC/laplacian_small.pdf

Cheers,

AM

[Andy Moorer]

While I'm at it, here's the DBM lightning blender plugin I alluded to earlier http://funkboxing.com/wordpress/?p=301 and an image of an early test generated by my setup (the post-glow in nuke is basic, glow on lightning is another story altogether- to do it correctly you have to go through some tough steps):

[Alan Fregtman]

I've a simple formula:

Arnold volumetrics + ICE lightning = Oooooooohhhhhh :D

;)

[Juhani Karlsson]

That is .assome formula man! : o

2011/9/27 Alan Fregtman <alan.f...@gmail.com>