The “accelerating” shadow effect (Bioshock)

[Walter Soyka]

[Tim Shundler] “I want to use a similar thing in one of my intro videos, however I would be using it in a horizontal manner only, speeding from left to right, slightly below and in front of the subject, casting a shadow on a wall behind the subject… I’ve experimented using “drop shadow” effects, but, perhaps obviously, these fall short. I wouldn’t exactly call them dynamic.”

Rather than using the drop shadow effect, I’d build your elements in AE’s 3D space, add and animate a light, and allow the background to accept shadows from the foreground elements.

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
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[Tudor “ted” jelescu]

You can also use a 3D plugin lige FreeForm Pro to create a 3d extrudet text that can take lights and cast shadows. Zaxwerks Invigorator Pro is another good tool for this job.

Tudor “Ted” Jelescu
Senior VFX Artist

[Kevin Camp]

you can fake this pretty easily if you can make the shadow casting elements as a shape layer. then you can use the repeater function to create the shadow.

to quickly illustrate, create a text layer (type anything) and set the color to black.

then choose layer>create shapes from text. this will create a new shape layer with the text as ‘shapes’. move it under the text layer, turn the text layer back on and set the color to white.

back to the shape layer, twirl down the layer properties and to the right of the ‘contents’ is a menu ‘arrow’. click it and choose ‘repeater’.

you should see a few copies of the shape layer, each offset to the right by about 100 pixels.

twirl down the repeater properties and increase the ‘copies’ value (try 25 for starters, you can change it as needed). then twirls down the repaeter’s transform properties and set the position to something really small, like -0.2,-0.2, and you should start to see a very similar shadow effect.

you could just animate that position property to animate the shadow, but to make it easier add a point expresion control from the effects menu to the shape layer.

then add an expression to the repeater’s position property (select the property and choose animation>add expression).

in the expression field add this expression:

(effect.(“Point Control”).(‘Point’) – position) / content(‘Repeater 1’).copies

now, if you select the point control effect (in the effect controls) you should be able to drag the point control around in the preview window to effect the shadow and keyframe that point to animate the shadow.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Paul Connors]

Hi,

I really enjoy your trick to animating the shadow effect from the Bioshock trailer, but I ran into a problem towards the end of your explanation.

After I applied the Point Control expression to the shape layer, when I add the expression that you wrote out to the Position property of the repeater I get the following error message:

After Effects warning: Function (predicate expression) cannot work with this class
Expression disabled.

Error occurred at line 1.
Comp: ‘Comp 1’
Layer: 2 (‘AICPA Outlines’)
Property: ‘Position’

Any ideas?

Thanks!