refracting shockwave around character? Can AE do this?

[Aharon Rabinowitz]

This was probably done in 3D or with 3D particles and 2D compositing, but it can be done in straight 2D as well. In both cases you’d need to do some camera matching – most likely they used camera matching software like Bojou. Synth-eyes is a cheaper alternative.

Also they probably filmed Tom Welling (Clark) on a Green screen to seperate him from his mother and the BG. If not they had to do some rotoscoping to seperate him for the effect.

If your camera is locked down (that is, it’s not moving), this will be a lot easier. You need to create distortion, and the best way to do that is to use a displacment map.

Rather then try and describe how displacment maps work, check out the Displacment Map tutorials (3 parts) that I did, by clicking on my head (I’m the dude in the green floppy hat). You’ll find those Displacement map tutorials it that list.

—————————————-
Aharon Rabinowitz
aharon(AT)yahoo(DOT)com
http://www.allbetsareoff.com
—————————————-
Creative Cow Master Series DVD
particleIllusion Fusion Volume 1
available @ http://www.pIllusionFusion.com

[Shane]

Ok, thanks Aharon. I’ll check out those tutorials. I do have access to boujou, so tracking will not be an issue.

I’ll see what I can come up with.

[Shane]

Well it looks like im running into some problems here with this type of effect. Aharon, I watched those disp. tutorials, (which were very helpful), but I think what im wanting to do involves going further then just using a disp. map.

The footage I am working with will be 3D. There is no live action, just a 3D animation ive rendered out.

In the video I posted, you can see the distorted waves following around Tom Welling as he takes off. Almost as if the air behind him is being displaced.

Will I need multiple copies of the original animation to get that kind of effect, or is there a better way to do this in 3D?

I consider myself to be an intermediate when it comes to 2D/3D, but this has left me boggled.

Any ideas would be helpful. Im hoping I can pull this off.

Thanks

[Aharon Rabinowitz]

You need to seperate out your forground and BG objects. So if your BG is being displaced, you need to be effecting only the background. If your elemts are on the same layer, then the displacement map will effect everything.

Don;t foget, you can generate a displacment map in your 3D program using black and white particles, or scaling up rings over time. A displacment map need not be created in AE. Any image or video can be a displacement map.

So, in short, you should render your elements seperately (BG, forground, displacment maps), or have them on seperate layers, and apply the displacement map only to the layer being displaced.

[Shane]

Ok. I see what you are saying. Im guessing I can create an animated disp map in 3D using black and white noise on a particular object, then render it out as a seperate pass and use it as the disp map in AE right?

I can see where this might get a little confusing to someone with little knowledge of how this works.

Thanks for the help!

[Aharon Rabinowitz]

no need to render – just precomp the particular effect – but yes, you can do it that way.

—————————————-
Aharon Rabinowitz
aharon(AT)yahoo(DOT)com
http://www.allbetsareoff.com
—————————————-
Creative Cow Master Series DVD
particleIllusion Fusion Volume 1
available @ http://www.pIllusionFusion.com

[Shane]

Ok, ive got my scene rendered out (along with an alpha channel for the 3D character). I noticed in the video that the distortion that builds up around Clark (as the camera orbits around him) is moving downward, and as it approaches his legs and feet, it looks like it slows down, as if it were pooling on the ground.

Is there a way in AE to make the disp. map act like that? Fast moving at the top, and as the lines for the disp. come down, they slow down and start to collect at the bottom?

I hope that made sense. Its kind of hard to describe.

[Aharon Rabinowitz]

A displacement map effect simply uses the pixels in an image or video to displace the pixels on your effected layer.

To get that effect, where parts move fast and parts move slow, you’d have to animate your original displacement map footage elements (your particles or whatever) to behave that way.

—————————————-
Aharon Rabinowitz
aharon(AT)yahoo(DOT)com
http://www.allbetsareoff.com
—————————————-
Creative Cow Master Series DVD
particleIllusion Fusion Volume 1
available @ http://www.pIllusionFusion.com

[Shane]

Ok, im understanding it better now.

Now what about “air distortions” following a character? Can that be done using an alpha channel as the disp map? I’ll explain….

Lets say that I have a character running and I want to add some distortion behind him so that it looks like one of those bullet trails from the matrix.

If I render everything out in passes, couldnt I apply some distortion to the characters alpha channel, then use it as a disp map?

To show you want im talking about, check out this vid. https://video.google.com/videoplay?docid=-5099018035894142914&q=smallville+football Clark is running, and you can see the distortion he’s leaving behind. Im sure they used a disp map for this, but how did they get the distortion to stay behind him? Its almost as if they created a matte just for him, and added something to it, to delay it, so it would stay behind him, like multiple copies. I hope im explaining this correctly.

Thanks for taking the time to help.

[Aharon Rabinowitz]

you might try using the effects >Time > Echo Time effect to create multiple instances of your runner. Precomp that and use that as the displacement map.

—————————————-
Aharon Rabinowitz
aharon(AT)yahoo(DOT)com
http://www.allbetsareoff.com
—————————————-
Creative Cow Master Series DVD
particleIllusion Fusion Volume 1
available @ http://www.pIllusionFusion.com