NukeX
All things NukeX.
Mainly intended as “note to self” while learning, but great if it answers your question aswell !
Modifiers
Drag and drop to switch nodes drag and drop and hold shift + ctrl while releasing the node
switch inputs shift + x
Always…
Add filters to premult images
Grade unpremult images
Transform premult images
A over B
Merge
Disjoint over:
not available in Shake, although you might have rolled your own techniques to do the same thing. Ever had to deal with two renders held out by each other? A straight over would leave a small seam where the two elements overlap, because the over operation does a holdout on the background itself, therefore leading to a double-holdout (double premult) issue. That’s where disjoint over comes into play. Essentially, what it does is unpremultiply B wherever it overlaps with A before doing the over operation.
DAG
To branch out a node instead of inserting it in the flow hold shift when creating the node.
To replace a node hold ctrl when createing the node.
Curves
Color lookup
To add an edit point to the curve ctrl + alt click the crv.
To move free ( x & y ) hold ctrl while LMB dragging.
To edit the tangents free tangent weighted hold ctrl while LMB dragging.
Mattes & Masks
To mask an image in nuke one way is to use the merge node. Two operations to be used for this is the stencil and mask.
The stencil operation punches out a hole where there are white pixels in the alpha channel.
A stencil B = the white pixel in image A alpha channel will stencil a hole in image B.
The mask operation will display the masked image where there are white pixels in the alpha channel.
A mask B = the white pixels in image A will display (mask) the pixels in image B.
TIP !
When you create new alpha channels with in Nuke make sure that the stream is premultiplied before merged over a bg. i have done this a couple of times and it seems like an easy thing to overlook if you come from a afx background. The stream to the right is premultiplied and stream to the left is not. Notice the difference !
Copy Channel (single)
Lets say that we wish to copy a channel from one node to another. Then we do like this. First we select the node we want to copy from then to node we want to copy to and press k to create a copy node. This will automagically connect up the nodes. it is important that the background is connected to the B pipe and the node to copy from is connected to the A pipe. Think of it like this “A copy to B”. The default channel to copy is set to alpha, if we want to use a rgb image as the alpha we need to make sure that some of the rgb channels is selected in the list as the channel to copy. See image below for a visual ref.
Copy Channel (multiple)
We could also use the copy node to copy multiple channels into the stream. Repeat the steps above to insert a copy node into the correct place in the stream. (A copy to B remember :)). The we need to create a new layer to store the channels in. in the copy node in the layer to copy dropdown we select new. This pops up the new layer window and we can entar a new name. Give the layer a descriptive name. Then we add in the channels that we need. In our case since we will insert a reflection pass we only need rgb. Then we simply connect up the channels rgb to the corresponding channels in the new layer. See image for ref.
ShuffleCopy node
To copy multiple channels there is a better node to use, namely the shuffleCopy node. This will do the same work as the copy node above but with a little less effort.
Connect the 2 pipe to the bg (that has the channels that we want to keep and add to) and the 1 pipe to the node to copy. If we want to pipe through the rgba of the 2 node we need to check the rgba of the “2 in checkboxes” see image for ref. To copy in the channels from the 1 node we first need to create a layer to hold the channels. On the right side at the bottom we click the dropdown that says none and selectws new. We give the layer a descriptive name and chooses the appropriate channels to include. Then we selects the check boxes at the left side at the bottom to sdpecify which channels we would like to pass through to the channels in the new layer.
