Editing control points

show more Editing control points provides you with in-depth training on 3D + Animation. Taught by Steve Wright as part of the Nuke 6 New Features show less
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Editing control points

In Nuke 6 the GridWarp node received measure improvements in both new features and stability. It can be used to both warp images as well as do morphs. The GridWarp node is best suited for situations where you don't need a great deal of fine control. For those situations, you'll want to use the SplineWarp node. To see how the GridWarp node works, let's load an image. So we'll punch up our Read node and we'll select our Project Media and look for the purple face and open that, hook it up to our viewer by typing 1, and I need a little bit more viewer space, so I'm going to make the viewer a little larger.

To attach the GridWarp node, we select the Read node, come up to the Transform, tab and slide down to GridWarp. And I'm going to push in a bit on this. We don't need the Read node property panel so we'll close that. Over here of course is the GridWarp property panel. Over here on the left, there is a new set of controls. These are for changing the GridWarp itself. Up across the top, these control the warping, and morphing, animation, and other effects. We'll take a closer look at both of those a little later.

Well, let's start by editing a control point. All you have got to do is click and drag on the control point. You can also adjust the spline tangents, the control handles. If I click and drag on the handle, I can pull it out. I can rotate it. I can rotate the other one. With a Shift+Click+Drag, both tension handles are adjusted the same. A Command+Click will break the tangency. To put it back, right-mouse on the control point and select the Smooth option, and that puts the tangents back.

I'll click off to the side to deselect that control point. If you disable the node with the D key, you can see your warp come and go. You also might want to put the cursor in the viewer and type the O key to get rid of the overlays and disable the GridWarp node so you can see your warp even better. I'll turn the Overlays back on by typing O in the viewer. You can also use the same 10 key pad nudge for these control points as you can in the RotoSpline node. So let me zoom in to this control point. I'll select the point and on the 10 key pad, put your middle finger on the number 5 and the 8 key is right above it, so if you go 8, 8, 8, 8 you're going to go up.

4, 4, 4, 4, you're going to go left. There are also two modifier keys. Hold down the Shift key and go Shift+8, Shift+8, Shift+8 to go up; and Shift+4, Shift+4, Shift+4 to go left, because the Shift key does a 10-pixel jump. Holding down the Command or Ctrl key actually reduces the precision, so we get 1/10th of the pixel per poke. I'll we re-home the viewer and click off to the side to deselect. Another important control is the Resize to Image button.

That amounts to a reset, so that will reset the grid back to the default position. And I'm going to zoom back in to the viewer for another closer look. Another important new feature is the Transform controls. Again, just like in the Roto node, if you select several control points, like this, you'll get the Transform control and in the middle, this will give you a translation. You can of course do a constrained scale in X, a constrained scale in Y, or scale the Y and the X at the same time. And you can even rotate them.

I'll click off to the side to deselect and click on Resize Image to reset the GridWarp back to default. One other important control point editing feature is the Curve Editor. You can select a point, right-mouse pop- up on that point, and select Curve Editor. Now you can put in just the position of that point or its tangents, or both. For simplicity, we'll just look at the position. Select that. It jumps down here into the Curve Editor. I'm going to float the Curve Editor so we can get a better look.

So starting at the top of the Curve Editor is the GridWarp node itself. We'll unfold that, and that's our destination grid, which is what we're working on, then the Curves. This is row 3, column 3, and there is our position X, Y for that point. So now I can go into the Curve Editor and if I move this curve up and down, I'm moving the horizontal position, or the X position. This curve is the Y position. And of course, if I had keyframe animation, I would have control points over the whole length of the shot. And we'll close the Curve Editor.

Now that we know how to edit the control points, let's take a look at how to edit the WarpGrid itself.

Editing control points
Video duration: 4m 49s 4h 6m Intermediate Updated Feb 13, 2012


Editing control points provides you with in-depth training on 3D + Animation. Taught by Steve Wright as part of the Nuke 6 New Features

3D + Animation Video
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