Water mask affects entire Cesium terrain when combined with other material layers

Cesium for Unreal
1

Hi ,

I’m working in Unreal 5.7.1 with Cesium 2.21.1 tileset materials and I’m trying to apply water only inside specific areas using the Cesium Water Mask material. I have multiple polygon raster overlays (water, sand,grass etc) each having their own cartographic polygons. The water mask itself works correctly when it’s the only layer in the material instance(which is applied to material and water mateiral of the tileset), but as soon as I add my other layers (sand/grass/asphalt, etc.) into the same material instance, the whole terrain gets affected. It’s like the water shading/lighting is influencing the whole tileset, not just the polygon area.

If I keep only the water mask layer inside my material instance, then water appears correctly only inside the polygon, no issues on the terrain, but If I use water mask layer with other layers: the whole terrain looks disturbed. I am using blank 3d tileset streaming from local Tile Management server.Anyone faced similar kinda problem before?

Thanks!

2

Hi @dis_afise,

Thanks for explaining your approach in detail. It would still help to learn more about your situation; I have a few questions at this point:

  • What does your tileset material look like? How many material layers are you using?
  • Does each polygon raster overlay use a different Material Key?
  • Can you share minimal steps for us to reproduce this behavior in our local environments?

Thanks in advance!

3

Thanks for your response.

  1. I am using 18 material layers in total. It includes the material layers present in default MI_CesiumThreeOverlaysAndClippingAndWater.
  2. Yes,each polyogn raster overlays has it unoique key and set of polygons assigned to them.
  3. As I am in the offline setup so I am using blank 3d tileset streaming from TMS server and I have added tile map service raster overlay for the imagery. I have assinged my material instance to both the material and water material attribute of the tileset rendering section.
    Looking forward to you response. Thank you!
4

Hey @dis_afise,

I think it would be helpful if you tried to reproduce this in one of the Cesium for Unreal sample levels and shared the minimal steps with us to make that happen (step by step is the most helpful rather than a brief description of the setup).

Having the minimum amount of steps to reproduce this issue is the best way for us to be able to help you. If you can share your project with us here (if there is nothing proprietary) that could be helpful, otherwise once reproduced with safe to share data/assets in a Cesium for Unreal sample level that could be shared as well.

If by any chance you have resolved your issue yourself since your last post don’t forget to update this topic with the resolution!

Thankyou!