This week we focused on green screen techniques. The multiple nodes that Nuke provides for removing green screen and how they differ. With that in mind we also went over several green screen techniques to fix common issues like spill. Alongside that we learned how to average out a green screen to make it easier for the nodes to remove it cleanly. That being said I will have to go back and review these lecture notes as it was a lot of information and some techniques weren’t properly digested. I would say this is my largest and most consistent issue when it comes to learning Nuke. Given our short time in class there’s very little time to ask questions about specific issues we face in Nuke. These issues are of course personal and from a variety of potential problems that need time to be tackled and may not help most other people in class.
We had homework to test out our green screening techniques. Pictured below is my final alpha for the green screen which to me is pretty clean. There do appear to be some issues with it though it doesn’t appear to be reflected in the final comp so perhaps they aren’t an issue? One thing I was wary of is that the green box on the machine behind the mad scientist was having its green removed. To fix that I just roto’d the box and tracked it very simply and after the scene was green screened just placed it on top so as to maintain the color of the box. One big issue with this is that the de-spill hasn’t worked as intended and you can still see some green on it especially when his arm swings and you can see green around the balls.
In my garage this week I was aiming to add texture to the wall of the scene to make it more grimy and rundown.
While for the most part its successful I have a continued issue where my roto shifts and moves around so it looks strange and as a result elements in the scene like my poster and spray paint don’t remain fixed in place. While I try to fix it through importing the tracking marks from previous files and making my own again it results in even worse tracking than when I simply placed the elements myself into the scene. I also lack the time to redo the rotoscope with proper techniques and to experiment to fully grasp nuke’s 3D scene roto.