Expand Edge

Written by Mateus Grasso on .

hello my name is matt!

one day a friend showed me this gizmo and today I will explain how it works :D

It is similar to colour smear that you can find here: http://www.nukepedia.com/written-tutorials/colour-smear-for-nuke/

I really recommend looking at the colour smear tutorial to better understand how it works

the idea is the same but instead of using blur and unpremult to make our extend edge we will use IDistort..

So let's do it!

1: Input your ALPHA in your target
Expand v001.0001

2: Add a Blur with size 6

Expand v002.0001

3: Add two transforms x = 1 and x = -1 and merge(from) them respective (A-B)

Expand v003.0001

4: Add more two transforms y = 1 and y = -1 and merge(from) them respective (A-B)

Expand v004.0001


5: Use shufflecopy to output those results In Red and Green Channels respective

X = red

Y = green

Expand v005.0001

6: Use a copy node to translate what you created to the Forward Channel

Red to Forward.u
Green to Forward.v

Expand v006.0001

7: Add a IDstort with 6 in UVscale and then erode(filter) value of 2 the matte

Expand v007.0001

8: Invert your matte and add a Blur with size 2

Expand v008.0001

9: Premult :P

Expand v009.0001

10: Merge over your target

Expand v010.0001

11: Add a Mask Input

Expand v011.0001


12: see if its working lol

Expand v012.0001


Expand v013.0001


The nodes that you would want to tweak for getting the effect that you want are:

The blur in the step 1, For tweaking the UV slope

The IDistort in the step 7 for tweaking how much you want to extend your edge

The erode in the step 7 for tweaking how much you want to over in your target

The blur in the step 8 for softing the matte edge

The mask in the step 11 for masking where you want

Create a gizmo with this knobs linked in them and you are in good way to go hehe :D

That's it, Have fun!!


+3 # Alexey Kuchinski 2016-01-22 17:30
Thanks Matt!
+1 # Raoul Ventel 2016-02-02 23:29
Great tip! thanks!
+2 # sridharan K 2016-02-28 20:10
Good One :)
0 # Praveen E 2018-03-09 05:15
super tips..

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