Fatal shadow error/glitch? Urgen help needed.

Hi forum,

I have having errors on occasion that are pretty severe in shadows. It is on a huge map, a 1-3 model of the entire Island of Bora Bora in French Polynesia, imagined as it will look in 100 years from now. It was on Unreal Daily Pic a while ago.

Anyway, I often get these strong odd shadows. They come and go quite fast, but they are really visible and always occur on the same textures, same places. So they are not random glitches by my GPU (gtx 1070).

Any tips? I tried to force all light maps to 2048.

All lights are dynamic: Because of the scale of the map. No other way. Its HUGE. The video run through takes 20 min in itself (Gonna post it here soon too and share with everyone).

Feel free to let me know if you have an idea what causes this!



I have included an image, a close up, of the error when it occurs. It always occurs on the same places, same time etc.


this problem is called shadow acne, there’s other posts in the forum about it with potential workarounds (don’t have any at hand, sorry)

btw if all your lights are dynamic then changing the lightmap resolution has no effect (those are only for static lighting)