Simulating rolling shutter in Post Process Material

I’m trying to implement a rolling shutter effect in ue4. High frame rate is not really a big concern for me as I’m probably gonna export the result raw video stream using a scenecapturecomponent at ~10-30fps.

My first thought was to simply render a bunch of consecutive frames and combine rows from the different frames to a final image. This would be almost like a brute-force solution and probably the most accurate in terms of capturing vertices that become visible and occluded between the frames.

I do however want to investigate if I could emulate the same effect in a post process material. I figure if I got access to the velocity vector of the camera I shift pixels around based on this. Ideally if I got the velocity vector from the previous frame as well I could interpolate the velocity between the two.

My question is if such post process material is possible, and if so how I can get access to the velocity vector. I can only find “WorldPosition”. Any other advice is also appreciated.

You can fake it by using UV distortion. But you will have to crop the frame to hide overlaps.
It actually should be very cheap PP filter.

I should note, it won’t be a proper rolling shutter effect. Since it wont respect moving objects. (You need to modify ue4 source to get a velocity g-buffer in case you want to use that data.)

Is it possible to use same information as motion blur to find motion vectors?