Nuke Homework: Replace the posters

Gonzalo assigned us a homework task to replace the posters in a street shot.


The entire node
Added planar trackers
Downloaded three images on the internet
Put posters
Slightly colour graded
Roto the pole

For this assignment, I decided to build the node structure from the ground up. While I referred to the basic node construction he provided, I took the initiative to create the rest of the structure on my own. I made an effort to organize the nodes effectively, although I’m not sure if it’s the optimal approach—I simply did my best.

This is the final output of the processes.


There was a challenge that I could not blend the image on the wall. I utilized a Merge node with multiply, and the source image was connected to the Cornerpin node. However, unexpectedly, the alpha of the cat image disappeared. Despite trying to address the issue with a Reformat node, it didn’t resolve the problem. Eventually, I resorted to creating a mask in Photoshop. Although this workaround worked, I’m still curious to understand why the alpha channel issue occurred and hope to find a solution in the future.