Touring the Interface with a Basic Composite - Nuke 101: Professional Compositing and Visual Effects - page 34

Treesusuallyflowinthisway,fromtoptobottom,butthatisnotstrictlythecaseinNuke.
Trees can flow in any direction, though the tendency is still to flow down.
Another example of a Nuke process tree is shown in FIGURE 2.2 and this is a much more
complex tree. The black boxes are all images that are being processed and connected to-
gether with a large variety of nodes. The flow of this tree is down and to the left. At the
very end of this tree is a yellow box, which is where this tree ends. Pretty daunting image.
However, when you are building this flow of nodes, you know exactly what each part of
the tree is doing.
Figure 2.2. This is what a more complex Nuke tree looks like.