Hi,

Can you tell a bit more about your project, like which water plugin are you using with which material?

Using WaterMeshActor and WaterBodyOcean actors I couldn't recreate the issue. The water was correctly visible behind the billboard:

Warmest regards,

Hello Eifert,

Thank you for your help.  I have shared my Unreal Engine for Aximmetry project here (which includes the water) :

https://drive.google.com/file/d/1-r0zaHcNJKoUCfECfv0wy9WyLmHK5MvQ/view?usp=sharing

It might be easier for you to just load the project and see what it does yourself and I am open to what I need to modify on the water material to make it not disappear inside the billboards.

Hi,

Your Wave (water) material uses CustomDepth. Aximmetry billboards also use Custom Depth. So either you disable it in Aximmetry billboard materials or in the water material. The Aximmetry billboards use it to fix the TAA on objects in front of the billboard, more about that here: https://aximmetry.com/learn/tutorials/for-aximmetry-de-users/how-to-install-and-work-with-the-unreal-engine-based-de-edition/#setting-up-objects-in-front-of-the-billboard 

To disable it in Aximmetry Billboards, go to Aximmetry_VirtualCam_3-Bill>Materials>Shaders:

And disable Allow Custom Depth Writes in Billboard_Lit and Billboard_Unlit materials:

Note, you will have to do this each time you add the Camera:

To disable it in your water material (if you don't want to disable it in the Aximmetry billboards), open the N_Wave_Inst material and set CustomDepthMultiplier to 0:
I found this didn't cause any visual difference in the water shader. I couldn't exactly decide why does water shader use it.

And thank you for sharing the project. You can remove it now.

Warmest regards,

Thank you so much for the detailed explanation on why this didn't work and the workaround/solve for this issue.   Greatly appreciated!

Warmest regards,