How to make someone appear as a car passes through the FOV

[Nick Meyers]

i think you need to story board this sequence.

“walking on the street towards the railing of the bridge”

sounds like they’re walking away from camera?
so how do we know it’s the same person as was in the truck?

you don’t really need any vfx or compositing either, in my mind.

1. establish the drier of the truck. MS driver in cabin. driver looks up, maybe sees something, cut to:
2. empty road, (WS) truck goes thru frame
3. cut down the line to MS of truck wiping frame to reveal driver on side of road
the closer shot will allow you to clearly see it’s the same person.

an alternate shot 3 would be a tracking MS in front of the person as the truck goes by on the right of frame
the only magic is in the editing.

if you want the magical effect of the empty road / truck by to reveal person, then yes, you do need some fairly simple compositing.

as with all vfx, shooting it properly in the first place makes it simpler.
locked off camera
shot 1 WS empty road, truck drives thru
shot 2 WS road with driver, truck drives past

shot 3 safety pass of driver on road, NO TRUCK
just in case

get the driver to go at the same speed both times
so the driver would not be the “driver ” character, but a different person, wearing the same clothes
the truck will be going so fast you won’t be able to see clearly the driver.
you need to be able to do both shots fairly quickly one after the other so the lighting and bg don’t change too much

the truck may well be kicking up some dust, or have some sort of exhaust,
so NOT having the truck go by in the character shot would not make for an easy composite, and the frame would be too clean.

in FCP line up both shots as closely as possible on V1 and V2
1st thing to try would be a simple jump cut
next thing would be a full frame wipe, either a transition, or a key-framed crop.
next step up in complexity would be a key-framed garbage matte.
these are relatively crude in FCP,
you get more control in Motion or After effects

of you cant match the 2 shots, you can revet to the clean truck-less shot,
and comp in the truck.
that’s a more complex rotoscope job,
you might be able do it with a keyframe garbage matte, but the dust exhaust issues would be tricky to deal with.

nick

[Mark Suszko]

This effect would make me forget about your story, and worry instead about a driverless truck left careening down a street. 🙂

But How I’d do it is to shoot the empty frame/ man on the street/ walk sequence first, as a locked-down plate shot, then while still rolling, get the truck to drive thru the empty frame.

You can download an 8, 12, and 16-point multi-point masking tool for free, and use it to mask around the truck, using keyframes. (Google Paul Crisp multipoint masking tool for fcp7.)

This effect can also be done faster in FCPX, which has a fabulous drawn masking tool, or in Apple Motion. But in all three, I’m doing the same thing: the base layer is the guy standing and walking layer. Bottom layer has one edit cut in it: between the background with nobody, and the background with the character standing and then walking. The truck layer sits above, and wipes across the cut to reveal the change. The truck layer is the truck and road/lower part of the frame only. Truck is masked and the mask travels with it, using simple keyframing at the first, last, and middle frames. Any spots where the mask gets out of line, correct and add a keyframe there. Should not take long.

If the masking is too hard for you, you can try a soft, feathered wipe or a feathered crop effect animated across just ahead of the truck. Adding a little blur to the truck will also help.

[Jordan Andrew]

Guys,

thank you both for such good ideas to pull this off.

Maybe I should have included the premise to my short flick. The setting begins with a guy talking to a therapist. He is there because he attempted to commit suicide by jumping from a bridge and is telling the therapist the events of that day and how someone talked him down. And the plot twist is the therapist tells him that no one else was there on the bridge that day. And I’m going to have flashback shots of him having a conversation with himself on the bridge. So he had this epiphiphany that he, himself was the difference that day. And saved his own life.

That’s the idea behind that introductory shot of the bridge. So I’m going to try those strategies you guys mentioned to the best of my beginning abilities and get back to you after this weekend to let you know how it went.

Thank you again for the tips!

Jordan

[Nick Meyers]

painting the person OUT before the truck enters frame might be a better approach.
especially if the truck kicks up some dust or leaves some sort of wake.

nick

[Mark Suszko]

Very groovy lateral thinking there!

[Nick Meyers]

thanks 🙂

of course a lot would depend on the background:
moving trees, running water would make it harder.
especially as in an empty frame there is no “smoke and mirrors” to distract the gaze.

nick