CornerPin Helper For Nuke

A tool which creates helper lines between the CornerPin node’s points, making it easier to align them to partially occluded corners… 

Additional Functionality

I received a comment on my previous article (Roto Assisted Tracking In Nuke) which sparked an idea to create a tool for assisting with corner pinning in Nuke. 

It’s a simple helper node which you connect directly to your CornerPin node, and it creates lines between the points in the CornerPin. 

This makes it easier to align the CornerPin, for example when some of the corners are occluded but you can still see the straight edges between them: 

Aligning the points of a CornerPin node to the hidden corners using the CornerPinHelper node. 

If your screen insert is a rectangular image which fills the screen, you could of course just use that to help line up the image. But where this tool shines, is when you don’t. 

As a basic example, let’s say that you wanted to put this large red circle into the screen:

Large, red circle. 

To help get the perspective just right, you wouldn’t have any straight edges in the image to line up with the edges of the screen. By using the CornerPinHelper, however, you can easily line up the image with the screen:

Aligning the red circle with the perspective of the screen. 

You can download the tool here:

It uses the same sort of idea as we saw in the previous Roto Assisted Tracking In Nuke article linked above: expression-linking splines (in this case brush strokes) to the CornerPin’s points.

Feel free to have a look inside of the group node (select the node and press Ctrl/Cmd + Enter to go inside) and check out the expressions for the brush strokes, on each spline point, and in the Stroke tab of the RotoPaint node. 

The tool is plug-and-play: just connect it directly to your CornerPin node and view it. If you want to make changes to the look, the settings in the tool are super simple:

Choose the width of the lines, increase their spacing (if you want dots instead of lines), and select the colour and the opacity of the lines, in the settings. 

You could for example turn the helper lines into green and semi-transparent dots: 

Changing the look of the helper lines. 

I hope you'll find this tool useful. For more Nuke tips & tricks, see Nuke.