Customizing Nuke with Gizmos - Nuke 101: Professional Compositing and Visual Effects - page 493

guides, usually as boxes on-screen, to approximate where the image will get cropped and
where it's safe to place text. Safety areas may be displayed as two boxes, one within the
other. The outer one is called Action Safe , and the inside one, Title Safe . They are usually
defined as a percentage of the image's resolution, such as Action Safe at 10% and Title
Safe at 20%. Safety areas vary from one TV format to another (4:3, 16:9, and so on) and
from country to country ( FIGURE 12.1 ) .
Figure 12.1. An example of an image with safety areas.
Nuke's lack of these guides is sometimes problematic. You have to create safety areas
yourself and add them to your trees manually every time. Instead of having to do that
every time, this chapter shows you how to build a tool that generates this functionality for
you automatically. Neat, huh?
Building the Gizmo's Tree
ThefirststageofmakingaGizmoistocreateatreeintheDAGwiththefunctionalityyou
want.Becauseyouwantthetooltobeeasilycontrollable,youuseafewexpressionsalong
the way to link properties together and change them according to various situations. It is
important to have the tree work with any image as its source—the whole point of this tool
is to be able to add guides to any project you are doing. The main difference to consider
from image to image is the resolution.
Let's begin:
1. In a new, empty script, create a Rectangle node from the Draw toolbox and view
it in the Viewer.