Hello.
Currently, I’m testing UE5.1 version and 5.1 version’s SLW materials. When I use SLW with WPO that makes vertex normal render issue like attached video. SLW+WPO didn’t makes any problems when ue5.0.
How can I fix this? Have I to increase material instuctions for re-calculate vertex normals? Or EpicGames already know this issue?
Single Layer Water now supports Lumen reflections. The increased accuracy of the reflections probably exposed the incorrect normals more than previously.
If the angle of the face changes due to WPO then yes, the normals need to be updated accordingly in the material to avoid artifacts and get accurate lighting/reflection. If your WPO is being driven by a texture, then a normal map texture can be used.
If your WPO is being driven procedurally by a mathematical function, normals can usually be derived mathematically as well using basic calculus. There are several other ways to derive normals such as the “normals from function” node, but they are usually more expensive or lower quality.
This doesn’t solve the issue, unfortunately. As you can see, there are other normals in the original image, meaning that including a normal input into the material doesn’t solve the problem.
If normals weren’t calculated, the plane outside of the artefacts would all look like it’s pointing up.
Maybe this did solve the problem for the original poster, but I’m definitely having this issue despite recalculating my normals.
I’m starting to suspect some kind of project setting, because the same shader in a different project isn’t producing these artefacts…
Can you post the material, an example of the artifact, and an screenshot of your normal buffer?