After enabling Lumen, my water surface and the edges of objects have some strange effects. Is there any way to eliminate this effect?
Can you post an image?
picture please. i’m pretty sure i know what you mean. even entirely raytraced, reflective floors and even chrome balls have a bad blend of screenspace reflection residual. unfortunately you can’t disable those screenspace “artefacts” entirely. or i haven’t found the switch yet.
if you mean general screenspace reflection. it’s just how it works. outside of the screen there is nohing you can reflect so you get those edges. or the developer would have to do some border clamp math for the screenspace texture to not sample the emptyness.
Thank you for your answer. Now I have this situation at a certain camera angle, and there is a strange white color appearing in the picture, which I cannot eliminate.
I have a very strange phenomenon in a particular camera position
are you sure you enabled lumen reflections? those are just plain screenspace reflections. the temply bit is blocking the reflection. like the hexagon thingy is blocking the cube behind it. that is that artefact. you can’t reflect what you can’t see on screen.
this should actually work with lumen reflections. or are the mountains too far away? in that case you should check it the mountains appear in the lumen overview or mainly the reflection view. the limit for lumen surface cache is 200 meters. you could try to increase that. it’s in the postprocess volume settings. the lumen scene view distance controls the surface cache distance and the max trace distance controls the reflection distance. the upper limit is 800 meters, officially. beyond that distance you can only use the far field tracing. i have not tried that yet. or you gotta use hardware raytracing with hit lighting. that totally solves that issue.
Thank you, my image has changed after turning on hardware light tracing. Now the picture shows a black reflection
that still doesn’t look correct. it should actually be colored like the landscape. atleast does it in my test scene. hmm 
I found that if I changed the reflection part of Lumen, it would take on the correct appearance, and if I changed the reflection to independent ray tracing, it would return to its normal appearance. But then I’ll lose some of the effects of other positions
not sure what the issue is, then. you get no proper reflection with hit lighting? what sort of water material are you using? and which engine version. i don’t think it’s a hardware issue, in case you run an amd card. i cranked 5.1.1 all the way up and it renders just fine.
My settings are the same as yours.I am using the water plug-in included with ue5, and my version is 5.1.0. I did not upgrade to the new version because some of my projects may have problems after upgrading，Do you try to block a part of the water reflection in front of the viewing angle with an object like me?
Sky I’m using DynamicSky
The difference is probably that not all materials look the same in the raytraced version. An opaque block should look perfect, but certain materials can look very different in lumen raytracing vs the screen traces if they even have lumen RT representations at all.
okay. i have not yet had a full battle with the shader editor. pretty sure non default gbuffer materials can get wonky. steps that need to be processed when combining it in post. the raytracer does lighting, but i’m not sure it eveluates the full materials. i also tried the water materials in the water plugin. runs in the test map, but does not exactly render correct when used in a general way.
Exactly. Lots of materials have problems, especially transparent ones but also things that rely on camera vectors or distance fields, etc. Hit lighting works a little better in this regard than surface cache but it’s not perfect. But the screen traces are usually good enough to fill the gaps.