Compositing CGI with Bigger Node Trees - Nuke 101: Professional Compositing and Visual Effects - page 105

TheExpressionpanelshowsthefourexpressionsforthefoursubpropertiesofthe
Box property (X, Y, R, and T).
The expression for each of the four subproperties is par-
ent.CurveTool1.autocropdata. There are three parts to this expression, separated
by dots.
• The first, parent , tells the current property to parent to another property,
meaning copy values from another property.
• The second part tells which node, in this case CurveTool1, should look for
a property.
• The third part tells which property to copy from.
Youcanseethisisaverysimplecommand,onethatyoucaneasilyenteryourself.
Simply usethenodename, thenthepropertyname youneedtocopyvalues from.
Let's see the result of this expression in the Viewer—but first close the open Ex-
pression panel.
4. Click Cancel to close the open Expression panel.
5. Clear the Properties Bin by using the button at the top left of the Properties Bin.
6. View Crop1's output by selecting it and pressing 1 on the keyboard ( FIGURE
3.13 ) .
Figure 3.13. The bounding box is now a lot tighter.