In this series of NUKE tutorials, we will take a look at every property of the Transform nodes, which allow us to move, rotate, scale, and do much more to our pixel data. We have our usual transform node, but we also have nodes that let us change the bounding box, distort our images, and even change our camera's movement. There are also several nodes that interact with the 3D system, including a Card3D node that lets us skip setting up a 3D scene and gives us direct access to 3D cards and a SphericalTransform node, which is very helpful when converting between different types of panoramic image types. We can also quickly and easily convert 2D position data into 3D space, or vice-versa by using the PointsTo3D node or the Reconcile 3D node. Along with all of these nodes, we also cover properties found in many nodes in NUKE, such as motion blur, 3D snap, and the filtering options. Software required: NUKE 6.2.
Chris is a VFX author at Pluralsight. Along with creating and recording training, he also manages the support team and works closely with the production development team. He began his career working freelance and quickly realized that he wanted to find a company where he could use his talents to help people succeed in the CG industry.
Introduction and Project Overview In this lesson, we're going to learn about the Mirror node. So here we are inside of NUKE, and I've just opened up the mirror. nk NUKE script. So the Mirror node is found under the Transform menu, and Mirror, so it has a single pipe input, and of course an output. Now, there's only really two properties we have to worry about, Horizontal and Vertical. So, let's now take a look at what Mirror does. I've got my one viewer piped into the left tree, and my right viewer piped into the two tree, and this is just to take a look at what Mirror does as well as what the Transform can do to mimic the Mirror. So with Mirror1 selected, let's now click Horizontal, and that simply flips the image in the horizontal axis, so let's uncheck that, Vertical flips it in the vertical axis. As you can see, both of these are very simple transforms. We could simply use the Transform to do these as well. These would tie together with a Scale, so let's go into our Transform and hit the 2 key, and a -1 Scale would be a Horizontal Mirror, you can see here that they're the same, and a -1 in the Height would be a vertical Scale, or a Vertical Mirror. To do both, the horizontal and the vertical, you can just do a Rotate of 180. Of course, you can type these into the Transform, and they'll work just fine. However, if you know you just need a very quick mirror, I would use the Mirror node to do that, because it requires very little processing power to do these kinds of operations, so therefore it's very fast. Of course, on a smaller image, the difference between a Transform node and a Mirror node is going to be very small or almost imperceiveable, but of course if you don't want to add in a Transform node, which of course can do anything, and want to make it very clear, to either yourself in the future, or other artists, I would use the Mirror node. There's one more strength of the Mirror node that let's quickly take a look at. I'm going to hit 3 to look at the Mirror input, and 4 to look at the Transform input, and you'll notice our bounding box is changing. With the Mirror, you'll notice that no matter what we do, our bounding box stays exactly the same as our source. This could be a strength, depending on what you need to do. As you can see here, no matter what combination of properties we turn on, the Mirror bounding box will stay exactly the same, however, in the Transform node, by default black outside is turned on, and so our bounding box will change. However, you'll notice even if we turn black outside off, our Transform node still slightly changes our bounding box. Again, that may or may not be a concern, depending on how your setup is. This also might be, actually, a weakness, because the Transform node has black outside automatically turned on, and the Mirror does not, so depending on how you use the Mirror, you may need to add a black outside node after the Mirror, to of course remove the issues that this check box does. If you'd like to learn more about black outside, we have a Node Reference Library lesson about that node and that setting. So, in this lesson, we learned how we can use the Mirror node to flip our images, either horizontally or vertically, and how we could use it together with both the horizontal and the vertical to rotate our image 180 degrees. Again, use this node if you know you're just going to need a very quick mirror. One last thing, you can also key these on and off, but of course there will be no interpolation, so as we move between frames, you'll notice that it just quickly goes from horizontally mirrored to not horizontally mirrored, so keep that in mind, you can animate this, however, there will be no interpolation per frame.