VFX I

7. Compositing


To integrate our CG with the background live-action we should consider matching the following:


Color

Color correction of CG. Adjust white and black point, gamma, saturation, shadows-midtones-highlights. Tweak individual passes such as specular

Shadows

Tweak the color, intensity, and softness of shadows
Is our shadow AO pass enough or do we need an additional light to cast a shadow?

Atmosphere

Add foreground atmosphere elements such as a very subtle smoke
Add a light-wrap node

Sharpness

Defocus the CG to match the background

Motion Blur

Camera motion creates motion blur, the amount depends on the shutter and speed of the motion

Render CG with motion blur or use a vector pass to create the motion blur in Nuke

Grain and Artifacts

Match the grain, compression artifacts, and chroma aberration

Lens Distortion

Add the lens distortion node created by the camera tracker to distort the CG


Guides

Color Correction: A brief tutorial how to match white and black point

Light Wrap Lynda tutorial (Login to NTUlearn first): How to apply light wrap to your comp

Vector Motion Blur from Arnold to Nuke tutorial on youtube

Grain: Furnace ReGrain tutorial on youtube

Lens Distortion: Follow the guide Lens Distortion and Overscan

Atmosphere textures like smoke are on our R-resource server at R:\ASSETS\videotextures