March 22, 2015

Three Quick Tips to Make Your After Effects Compositing Look Way Better

Basic After Effects Compositing Tips
Making your compositing look naturalistic is not as easy as it seems, but these quick tips will help.

Compositing is all about making disparate visual elements work together in order to create a unified final image. It can be as simple as taking green or blue screen footage, keying it, and placing a new environment in the background, or as complex as layering elaborate 3D animations into previously-shot live action footage. However, no matter what kind of compositing you find yourself doing, the basics never change.

In a brief tutorial on his YouTube page, Ruan Lotter at TunnelVizion TV recently shared a few tips that will help beginning compositors seamlessly blend visual elements:

Although matching the saturation and sharpness cues of your visual elements is compositing 101, it's still one of the dead giveaways of composited green screen footage in amateur (and sometimes even professional) productions. However, as Ruan showed in the above tutorial, it's extremely quick and easy to match the saturation and sharpness of your CG element or keyed footage to that of the background. It literally takes about a minute to accomplish both of those tasks. What's even better is that you don't really need a fancy compositing program to do either because all it requires is simple color and blurring tools which are available in pretty much every NLE.

Ruan's other tip here is a fantastic, albeit extremely subtle one. By using After Effects' "Match Grain" effect, you can emulate the digital grain present in your background footage and apply it to all of your composited elements. It may seem superfluous unless you're a perfectionist, but since it's so quick to do, and because every little tweak can really help to sell the final effect, there's really no reason not to do this.     

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3 Comments

The infamous teapot :). One of the best pieces of advice I received for photo-realistic 3d imagery is that the "mistakes" are often what make it believable. Grain, flares, textures etc. 3D can be perfectly symmetrical or have very hard edges, so softening can go a long way.

One thing I did notice about the video is that his lighting (specifically the shadow) does not match the video. You can see the reflection of a softbox in the tea spout even though the light source is from outside. VCP also posted some good tips for compositing a few years back: http://www.videocopilot.net/blog/2009/06/perfect-compositing/

March 22, 2015 at 11:18AM

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Jon Ford
109

Quite hard to comp something CGI on the plate with a png. That's why we comp this with multichannel EXRs. I'm a Vray user and for that normally I would go with render elements such as raw light, raw reflection, filter, AO, shadows on separated layer (maya user here), even utility elements such as normals and point position.

Also the reflection on the teapot is a dead giveaway. I would use a IBL render with a proper HDRI image from the actual plate, in that case, the room or something close, so we have the actual light from the environment casting shadows correctly, and also reflection. Those are major if you want something realistic in your shot.

But the mach grain and and adding a little bit of blur is crucial indeed. You could do even a "fresnel" pass or element in max or maya just to blur the edges according to this map depending on the look you want.

March 22, 2015 at 11:39AM

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Alex Mandarino
DP / VFX Generalist
247

Those are fairly basic tips anyone should know. Always match saturation, grain and level of sharpness/blur. Matching the lighting as close as possible on set is always a must, and taking some measurements to reproduce the virtual camera(if its 3D) will help sell it. Having a color layer and a separate shadow layer at the minimum is a good rule of thumb to at least make life easier. Cutting up the composite into 30+ layers/passes of color, shadows, specular, ect, could be overkill, depending on what you're trying to do. Not all composites need 100 passes anyway. Exaggerated but you get the point. And for that final sweetner, be sure to get you're Lightwrap correct.

March 22, 2015 at 12:37PM

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Josh.R
Motion Designer/Predator
980