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Apple Shake 4 Tutorials User Manual

Page 155

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Tutorial 4

Working With Expressions

155

4

In the Mult1 parameters, set the color to blue using the Virtual Color Picker. Hold down
the B key and drag to the right to boost the blue color.

It is rather subtle, but Brightness1 and Mult1 are concatenating their color corrections.
The Mult should tint the entire RBlur blue, but you can see that the center remains
white because Brightness1 internally raises the values of the center to around 1.5, 1.5, 1.5
(numbers are a theoretical example). When Mult1 multiplies the color by .7, .7, 1 in the
RGB channels, it lowers the color to 1.05, 1.05, 1.5. At 8 bits, this rounds down to 1, 1, 1,
which is white.

To view what occurs without concatenation:

1

Insert a Filter–Blur node between Brightness1 and Mult1.

With the Blur node between the Brightness1 and Mult1 nodes, everything turns a flat,
disagreeable blue.

2

Delete the Blur node to preserve the concatenation.

Concatenating

Non-Concatenating