Color Correction - Nuke 101: Professional Compositing and Visual Effects - page 199

You'll need another Radial node to define the second wheel. (You can add as
many Radial nodes as you need. Everything in Nuke is a node, remember?)
6. With Radial1 selected, insert another Radial node after it.
7. Adjust Radial2 to encompass the front wheel ( FIGURE 4.55 ) .
Figure 4.55. Using Radial nodes to create masks for color correction
8. To make use of the radials, you will take the mask input for Grade1 and attach it
to the output of Radial2, as in FIGURE 4.56 .
Figure 4.56. Attaching the mask input to the mask image.