Hi,
I tried enabling Field Shado on one of my projects I have some weird shadows behind objects moving at high speeds. I tried disabling Distance Field Shadow and whole shadow on buggy objects. I also tried disabling motion blur and even everything at once. Here is a snapshot of the undesired effect:
So, there’s a repeating shadow error of the car. A few things to try are:
Try turning temporal antialiasing off. This doesn’t look like a shadowing problem, this looks like ghosting from TAA, it’s very common in racing games.
You can try using a different AA method or you can try to implement a more elaborate solution to address it.
Thanks for your quick answers.
Unfortunately, given answers didn’t work for me. I kept searching and discovered that the problem might come from skylight’s Distant Field Ambient Occlusion combined with Distant Field Shadow. Changing skylight to stationary or significantly increasing Minimum Occlusion, problem disappears, but it also disables whole level DFAO as well…
Do you have anything else in mind?
What are the Skylight > Lighting settings? Is there an Unbound post process volume in the level, and what are its GI and AO settings (screenshots please)?
DFAO is naturally grainy and tends to ghost/band a ton, making it pretty crappy, but, if you need it, here you go
r.AOHistoryDistanceThreshold (May help)
r.AOHistoryStabilityPass (Set to 1, costs more but may help)
r.AOHistoryWeight (Will cause flicker, but, also fixes it)
Even then, if your just using it for car shadows, fake it via decal.
Isn’t that just due to temporal AA?
@presto423
Yes there is an unbound post process, I add all the screens
@Bits360
Ok so the r.AOHistoryDistanceThreshold fix the thing but the AO in the world is blinking now
@jonimake
No, I tried to disable all the Anti Aliasing, and the weird shadow keep going.
I set AO Distance Threshold to 1, Stability to 1 and Weight to 0.5. This partially resolved my problem. However, I still have AO flickering and artifacts on some surfaces. By decreasing AO quality to 1, flickering effect also decreases significantly but it doesn’t disappear.
Change Lower Hemisphere Color in skylight to a somewhat light grey. It might make the lines disappear, though they can still remain there, just not visible. If that’s the case though, then it probably has something to do with distance field shadowing and something in the skylight. Another thing to attempt is increase AO radius, resulting in surfaces further apart to affect each other in shadowing. The idea I have there is getting a more uniform shadow level with AO, potentially filling in those gaps of the car shadow’s bands.
Cubemap resolution of the skylight is rather low. At 256, it would result in far more accurate reflections and shadowing too, I bet…or 512.
Increase the number of skylight bounces to 2 or 3, and decrease intensity scale a bit (down to 1.5 at the most I think) to offset the change and dim it back to original brightness.
One last one, decrease AO intensity in the post process by at least .1 or .2. Then use the Advanced dropdown below that to access and modify the Exponent or Contrast properties. Increase those to re-intensify the AO shadowing while maintaining the light levels near heavily affected AO areas. It might help reduce the shadow banding for the animated car too.
