Hi all, I haven’t made a post on the Unreal forums before, so I apologize if the tagging is totally off on this. I’m also new to making materials in general, so the answer might end up being pretty obvious.
Today I followed this tutorial on how to make a fish-eye lens post-processing material. After getting a grasp on it (or, thinking I did), I decided to tinker around with it to try and get an effect more like this, where the distortion follows linear gradient on the left and right edges instead of a radial gradient. The problem is that the add node isn’t doing what I expect it to- I’ve worked with programs like Nuke, so I thought that I’d get the red borders on both edges of the mask. Instead, I get neither and only see black. I’ve tried different texcoord channels and appending, but no dice. Using separate channels seemed to work at first, but trying to add them causes only one channel to go through. Is there something I’m missing? I’ve been messing with this all day and I just can’t figure it out for the life of me.
The first image is what I’m actually doing, and the second image is something closer to the intended result. I would do it the second way, but I might be mildly neurotic with a tendency to brute force things 
Note: I’m only routing this mask directly into the emissive color pin for troubleshooting purposes. Even when I turn it into an actual distortion, it doesn’t look right.
