Hey Don,
Since you’re still new to After Effects, I’d recommend the following link, in which Adobe’s Todd Kopriva pulls together some important introductory materials:
https://blogs.adobe.com/toddkopriva/2010/01/getting-started-with-after-eff.html
The effect you’re asking for is deceptively complicated. I assume you want your paint to come out of the pressure washer, which means you’ll have to track its tip and create something spraying out of it (probably with a particle system). Starting the paint effect in Photoshop is a great idea, but you’ll want it to wipe on somewhat organically, which you can do with a combination of animated masks and fractal noise luma mattes (possibly a luma matte based on your spray particle system, too).
You can make this shot a lot simpler if you reshoot it so your friend walks backwards. Walking forward as he does, you have to rotoscope him as he crosses in front of the area you want the paint to appear. If you’re reshooting anyway, a tracking marker on the pressure washer nozzle will help, especially where the dark tip dips in front of the tire.
Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
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