Hi all
I am having extremely strange things happening in my shadows! Whenever the character runs into the shadows, these vaguely trippy tracelines occur around the body. This shows up very clearly in any renders. They also appear if i scrub through the sequence in preview as if the lighting doesn’t have time to catch up properly with the character movement. In preview the tracelines slowly disappear if I do not move onto the next frame. In addition, there is banding on the same mesh (which can be seen on the left side of render)
Any help greatly appreciated!
So, the tracelines and the banding are 2 separate issues.
Ghosting (explanation):
The tracelines you are seeing is commonly referred to as “ghosting”.
This is an artifact caused by temporal anti-aliasing (TAA) and in Temporal Super Res (TSR), which is the default anti-aliasing method in UE.
Temporal anti-aliasing takes samples from multiple rendered frames over time in order to smooth out pixels.
Therefore, the faster an object moves the more of a ghost it will leave behind from the previous rendered frames it sampled.
This will also appear on slower objects that pass near high contrast areas, such as in your case.
Motion blur can also contribute to this as well, which is enabled by default.
Ghosting (Solution):
1st, try disabling motion blur:
VIEWPORT > SHOW > POST PROCESSING > Motion Blur (untick)
Also, you can change this in your Post Process Volume
Next, if that isn’t giving the results you want, you can change the anti-aliasing method
Project Settings > Engine > Rendering > Default Settings > Anti-Aliasing Method
Try FXAA or none…although it won’t look great.
