Could you explain those weird reflections?

It always bugs me when I see this thing in UE games. I’m not a developer so it’s all black magic for me. I’d like you to explain this.


Do you see the reflection on the floor, coming from the blade of knife? It’s odd, reflections don’t work like this in real life. How does it even occur? Is it possible for devs to fix it somehow?
The example seen above is relatively moderate, but there’s the most ridiculous case I’ve ever seen: in one UE4 demo you could fly as an UFO around the map. There was also a big sea around it. If you flew way above it and had the camera close to the saucer, you could see the reflections of your tiny UFO appearing on the entire surface of water.
I can imagine this effect being a big aesthetic problem in games in which the player gets to fly over some water.

It’s due to the screen space reflections which aren’t precise.

What game is that? Killing Floor 2? It’s running on UE 3. Tripwire modified it to have screen space reflections.

Ah, so those are SSR… It seems the inaccuracy resulting in such artifacts is ingrained into this technique. Or maybe Tripwire didn’t use the best quality there, in order to achieve better performance?

It might be an issue with the depth of the first person hands not being in the right place