Apple Shake 4 - Manual (Page 691)

Chapter 24 Keying 691
HueCurves
The HueCurves node, located in the Color Tool tab, enables you to boost colors or
saturation based on the hue of the pixel you want to affect. HueCurves works by
loading a parameter into the Curve Editor and tuning it—ignoring the value fields in
the node parameters. The X axis is the hue, and the Y axis depends on the parameter
you are using. For the following example, load the saturation curve into the Curve
Editor and grab the control point around .66, since blue has a hue of 66 percent. Drag
the point down to decrease the saturation for the blue pixels.
Edge Treatment
Another typical problem when keying (OK, it is the problem with keying) is edge
treatment.
The following example uses two images from the $HOME/nreal/Tutorial_Media/
Tutorial_06/images directory:
1 In the Image tab, click FileIn.
2 Go to the /Tutorial_06/images directory and read in the pillar1.jpg and clouds1.jpg
images.
These images bring up an important tip for compositors: Supervisors are typically
optimistic about the results possible from using the sky as a bluescreen.
3 In the Node View, select the pillar1 node.
4 Click the Key tab, then click the Keylight node.
The pillar1 node is connected to the Keylight node’s foreground input.
5 Connect the clouds1 node to the Keylight node’s background input.
6 In the Keylight node parameters, click the screenColour control, then scrub the sky near
the horizon.