Color Correction - Nuke 101: Professional Compositing and Visual Effects - page 198

Using the mask input to color correct a portion of the image
Let's say that a movie director asks for the wheels to pop out of the image and have high
contrast. To do this secondary color correction, you will need to first define an area to ap-
plythecolorcorrectionto,thenuseanotherColornodeandusethisareainitsmaskinput.
You haven't learned to create complex mattes yet, but in this case you only really need
two radial mattes. You can easily create those using the Radial node in the Draw toolbox.
First, to brighten up the wheels, you will use the Grade node.
1. Select ColorCorrect1 and insert a Grade node after it.
If you use the Grade node as it is, the whole image will get brighter. You'll need
to use Grade1's mask input to define the area to work in.
2. With nothing selected, create a Radial node from the Draw toolbox ( FIGURE
4.53 ) .
Figure 4.53. Creating an unattached Radial node.
3. View Radial1.
It creates a radial, see? Itold you.By moving the edges ofthe radial box,youcan
change its shape and location.
4. View Grade1.
5. Drag Radial1's edges until it encompasses the back wheel ( FIGURE 4.54 ) .
Figure 4.54. Radial1 encompasses the back wheel.