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Motion Track an effect to a scene

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Joseph Wu
Motion Track an effect to a scene
on Nov 30, 2010 at 7:40:34 am

I want to film a gun fight scene, but i also want to have shattering glass to add to the realism. I saw a tutorial on how to use the shatter effect, but they are all stationary examples. The scene I will film will have LOTS of movement. Is there a way to motion track the shattering glass effect to the whole video?


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Walter Soyka
Re: Motion Track an effect to a scene
on Nov 30, 2010 at 2:41:40 pm

[Joseph Wu] "Is there a way to motion track the shattering glass effect to the whole video?"

Shatter has an option to use the comp camera. If you use a 3D motion tracker like Syntheyes or CameraTracker to solve your camera move, you can have Shatter react to the comp camera as if it were really an object in the scene.

Shatter is very cool, but it has some limitations -- it's 8-bit only, and its texture and light options are limited. For more realistic-looking glass with refraction (i.e., the glass bends light that passes through it) and reflection, you'll have to use a real 3D application.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Dave LaRonde
Re: Motion Track an effect to a scene
on Nov 30, 2010 at 3:28:43 pm

This kind of stuff is best done as a practical effect, and not with AE. You get the necessary realism because it's... well, real.

Walter's right in his recommendation of a 3D app, but even then, it would extremely tough to make it look real. If fake-looking is good enough, knock yourself out.

Or you could simply figure out a sequence of shots and stick to them religiously, using careful choreography, like they do in Hollywood. On a wide shot, a guy shoots a gun. Immediately cut to a different angle and the window shatters using a practical effect.

A lot of the action in action scenes comes from careful, well-planned editing. Shooting the whole thing on a side shot isn't very wise.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Walter Soyka
Re: Motion Track an effect to a scene
on Nov 30, 2010 at 4:00:48 pm

[Dave LaRonde] "This kind of stuff is best done as a practical effect, and not with AE. You get the necessary realism because it's... well, real."

Dave's right. I tend to think on the post side of effects, because I usually get a bunch of files and a brief, along with the expectation that I can make it work -- no matter what. Sometimes I can pull a rabbit out of my hat, but sometimes I have to scrap the effect and suggest alternate strategies, because there's no budget for a week's worth of post to fix what would have taken a couple minutes' worth of prep time on the shoot in the first place.

Since this hasn't been shot yet, and since you're shooting it, you should absolutely do as much practically as you can. Nature renders glass better and faster than your workstation does.

The other piece of advice I'd offer is this: for whatever effects you choose to do digitally, shoot tests and rough in the VFX before you bring your entire cast and crew in for the real shoot. You want to uncover any difficulties in photography or any problems in your workflow ahead of time.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Dave LaRonde
Re: Motion Track an effect to a scene
on Nov 30, 2010 at 4:04:54 pm

[Dave LaRonde] "Shooting the whole thing on a side shot isn't very wise."

Sorry, I meant to write, "Shooting the whole thing on a WIDE shot isn't very wise."

Neither is trusting that everything will turn out for the best in post-production once the shot's in the can.

Dave's Stock Answer #2:

When you're out on a shoot, and you say, "we'll fix this in post" without knowing PRECISELY HOW you're going to fix it in post, don't shoot it! You'll only end up shooting it over again.

Since post typically costs three times the cost of production, fixing something in post is not a way to save money, but rather a way to spend more of it.

And, before you say "well fix it in post," always consider who's doing the work, especially if you're the one doing the work.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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Kevin Camp
Re: Motion Track an effect to a scene
on Nov 30, 2010 at 4:56:00 pm

if you want to do some tests with shatter, shatter does have a corner pin setting in the camera settings, so you could try to track 4 corners of a window, apply those to nulls and use expressions to link the corner pin points to the tracking nulls.

that would probably give you the best 'registration' for a moving shot.

it may not give you the realism that you may need, but it may be good enough to enhance a shot, but you should do some test shots to see the limitations and to better plan your real shoot.

if you need cheap glass, try craigslist... you can often find cheap/free old single pane windows or even furniture that has glass doors that you can use. note, that it may or may not be safety glass, so you will not want talent anywhere near it when it shatters.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW


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Shawn Miller
Re: Motion Track an effect to a scene
on Nov 30, 2010 at 7:33:14 pm

I think you bring up a great point, Kevin. One of the biggest advantages VFX has over SFX is safety. I have worked on a few projects where actors have been injured by glass, simply because the proper respect wasn't paid to saftety. IMO, you either spend a lot of time testing practical effects and making sure that they're safe and look good (on film/video), or you spend a lot of time testing VFX and making sure they look good (on film/video). Either way, the point is the same; make sure you know what you're doing WAY before you start shooting. :-)

Thanks,

Shawn



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Ryan Hill
Re: Motion Track an effect to a scene
on Nov 30, 2010 at 7:23:19 pm

Dave, is there somewhere I can see a list of all your stock answers? :)



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Dave LaRonde
Re: Motion Track an effect to a scene
on Nov 30, 2010 at 7:29:26 pm

Sorry, at the moment I only have three, and one of them has been rendered rarely useless since the introduction of AE 10.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA


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