Adding Trails to Moving Objects

starixiom wrote on 1/25/2003, 1:04 AM
What would the most efficent way to isolate an object (in this case a person) and apply an effect that would create trails on their movement?

ie. A person walking in the background of a shot could be isolated so that you could see them walking (see the "trails" of their body movements/ arms, legs, body) without affecting other elements of the shot.

Comments

Grazie wrote on 1/25/2003, 5:29 AM
Welll . .. just a thought. I'm winging this - but here goes:

1. In track 1 place clip

2. Copy same clip to track 2

3. Apply motion blur to track 2

4. Reduce opacity in track 1

I told you I was having a stab at it!

Grazie
Cheesehole wrote on 1/25/2003, 8:13 AM
if the bg is not moving too much you could use one of the Pixelan plugins which does motion trails. if the camera/bg is moving, then you would have to use a mask to isolate the person walking. could get complicated!
Tom Pauncz wrote on 1/25/2003, 12:50 PM
Try the Plugin pac from Satish. Search back through the forum, I am sure you'll find references.
Tom
tadpole wrote on 1/25/2003, 3:15 PM
throw in a heavily feathered cookie cutter over the track with your blur/motion fx (to isolate whatever element you want to effect) and you got it!

Grazie wrote on 1/25/2003, 11:57 PM
Soooo . . tadpole . . was I correct? Does it work? I haven't tried it yet in VV - still "exploring" the forest of virtues!

tadpole - if it works, would you stick a small bit up on Chienworks site - so we can see it? PLeeeease. . . .

Grazie
tadpole wrote on 1/26/2003, 2:27 AM
of course it will work!
you can do pretty much ANYTHING in vegas!!

even though i have sooo many other better things to do (well, not really;).. i posted a quick (took me about 40 seconds to create) on chien's website
and of course! i had to add a politically charged statement! lol

(ps - when i was a kid, there was NOTHING that could ruin a perfectly good cartoon then when a "follow the bouncing ball" sing-a-long busted out!!! lol
Grazie wrote on 1/26/2003, 2:37 AM
tadpole -Many, many thx for your speed! Been to site - Nada! - I'll wait for it to appear. I suppose "tadpole" as the author - yes? Reeeally looking forward to seeing it.

Regards,

Grazie
tadpole wrote on 1/26/2003, 2:41 AM
well its nothing special.. really
first time posting to chien's site.. might not have done it right?
give me your email, i'll send it to you now

tadpole wrote on 1/26/2003, 2:48 AM
omg - i'm sorry, i'm all hosed up ...(late at night, i;m drunk, and got too many windows open) the video i posted was for a different thread about animating a "bouncing ball"

email me instead of posting - jmale2000@yahoo.com

I'll try to quick give you an example of THIS thread..
can't guarantee i'll finish it tonight, very tired - tomorrow for sure

sorry about that!
Grazie wrote on 1/26/2003, 2:55 AM
Okey Dokey!

Dunnit! Go to bed! - It's 9:00am in London UK now - what's it there? Where ever that is?

Grazie
tadpole wrote on 1/26/2003, 7:29 PM
Ok - In regards to "adding trails to moving objects"

Trails as in 'ghosting' an image would be very difficult in vegas without the aid of a pluginFX- and extremly difficult/time consuming if you only want it applied to a certain component in the video.

Whenever you want to 'isolate' a certain element in your video, your going to need to 'cut'/mask it out from background. Creating multiple masks in photoshop for each frame would work - but LOTS of time. If there is a strong contrast between the element you want to isolate and its surrounding, you could apply filters to exagerate the difference until you were left with a siloute-style image - which you could then use as a mask (would be easy if your subject was shot against a blue screen!) Or, you could use a cookie cutter mask (which would work fine for symetrical ojbects like a soccer ball)

After you extracted the element you want to "ghost", you could create multiple instances of the track & overlay it against your original video - off set each overlayed track slightly more than the one before it while adding fades to back of the track....
Almost as difficult as doing this, is trying to explain it!! sorry.

An alternative fx to creating "trails" (what Grazie & i were discussing)
- fx similar to movie superhero running really fast

Track 1 (original clip - lady running towards a bar)
Track 2 (duplicated clip - placed above Track 1)

Keyframed a feathered cookie cutter shape (side oval in this case) to follow the lady running towards the bar (track2)
**note, to make this easier, i usually apply a b/w effect to make track2 different then 1 - after i get the keyframing down, i remove the b/w effect

I then applied a sparkling light-rays effect to track2
Then keyframe the sparkling effect to say, be none existant before she starts running, then increase as she hits 'full speed'.. then fade the effect as she stops. (also good idea to play with the feathering/size of the cookie cutter mask)

Kinda of crude method (since you are using a shape as a mask), but it doesn't take very long to do.

Using this method with different fx filters, you can do cool things like colorize a certain element while the everything else remains black and white -

email me jmale2000@yahoo.com if you would like to see a demo clip of this.

starixiom wrote on 1/27/2003, 8:16 PM
I just wanted to thank everyone for their suggestions.