7. Customised shortcuts
Hotbox by Wouter Gilsing is an awesome user interface that includes smart customised shortcuts to quick change some custom values for any nodes without taking too much time to open the properties panel, or loading some daily setups we do manually, for example projection setup. This gizmo considerably speeds up the workflow once you take the time to customise it with your own preferences.
8. $GUI Expression
You can optimise your script and save time by preventing certain nodes (typically defocus, motion blur etc.) from contributing to the result, or have them work with certain values to speed up your work. These nodes will still fully execute when the script is sent to a render farm.
You can use this in two ways:
a. Disable the node in the Viewer by selecting the node and pressing Ctrl+D this will set a simple $GIU expression in the disable knob of the node.
b. Specify values to use while in the Viewer. To do this, right-click on the knob and choose ‘add expression’, then type the expression following this format: $GUI ? [value to use when in Nuke] : [value to use when on the farm]
For example, if you want a Scanline Render node to compute motion blur, but you do not want to compute it while working, in the ‘samples’ knob you would type this expression: $GUI ? 1 : 15. This translates as ‘if this node executes in Graphical User Interface, use 1, or else use 15’. This means Nuke will use 1 sample while in the Viewer, and 15 on the farm, speeding up your workflow.
Make sure to leave an explanatory note for the potential artist picking up your script, so they aren’t surprised when comparing the render and the output of the comp.
9. IBK Stacking Technique
A powerful way of using the IBK to pull a key, is to stack the IBKColor node, to create the most accurate clean plate before inputing the result into the IBKGizmo ‘c’ pipe.
To do this, first set up your IBKColour node: set the colour of the screen and the size to 1 (to preserve detail to pixel scale), then play with the ‘darks’ and ‘lights’ until you get rid of as much subject as possible, leaving a dark silhouette against the blue/green screen, then ‘erode’ slightly, to remove the last details like hair or motion blur, and ‘patch black’ at 2.
Here is an optional stage: if you still have a little subject detail, you can stencil them with a roto where you clamp and crunch the values, leaving only black and white values, nothing in the grey scale (essentially aliasing your mask).
Duplicate the first IBKColor node, chaining the 2nd into the 1st, and expression-link (Ctrl+drag) the values of ‘darks’ and ‘lights’ from the first one to the second one, set ‘erode’ back to 0, and set ‘patch black’ to 4.
Duplicate that secondnode and set ‘patch black’ to 8.
Repeat and multiply the ‘patch black’ value by 2 each time, until the black silhouette is filled.
Make sure to obtain a clean plate keeping the details of the blue/green screen so that the alpha will not retain them, only the subject.