# Changing water material in UE 5.1 causes ocean to turn white

**URL:** <https://community.cesium.com/t/changing-water-material-in-ue-5-1-causes-ocean-to-turn-white/21894>\
**Category:** Cesium for Unreal\
**Created:** [January 10, 2023, 3:03am UTC](https://community.cesium.com/t/changing-water-material-in-ue-5-1-causes-ocean-to-turn-white/21894 "2023-01-10T03:03:49Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Gabriel\_Transmira](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/gabriel_transmira/32/11923_2.png) [@Gabriel\_Transmira](https://community.cesium.com/u/Gabriel_Transmira)\
**Post date:** [January 10, 2023, 3:03am UTC](https://community.cesium.com/t/changing-water-material-in-ue-5-1-causes-ocean-to-turn-white/21894/1 "2023-01-10T03:03:49Z")

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Hello.

I’m using UE 5.1 from Epic Launcher and Cesium for Unreal from the Marketplace.

- Unreal Engine Version: 5.1.0-23058290+++UE5+Release-5.1
- Cesium for Unreal version 1.21.0
- Visual Studio Community 2022 (64-bit) version 17.4.3

I’m following the documentation on how to edit the water material. However, I seem to have encountered a bug. Here are the steps to reproduce the bug:

1. Download the Cesium for Unreal Samples project and Cesium plugin from the Marketplace.
2. Open the **01\_CesiumWorld** level.
3. Copy the **MI\_CesiumThreeOverlaysAndClippingAndWater** inside the Cesium Plugins folder and move it to the Content folder.
4. Copy the **MLB\_CesiumSimpleWater** inside the Plugins folder and move it to the Content folder.
5. Open the new **MI\_CesiumThreeOverlaysAndClippingAndWater**. In the Layer Parameters window, under the **Water** Material Layer Key, change the old **MLB\_CesiumSimpleWater** with the new **MLB\_CesiumSimpleWater** we just created. Save the material.
6. Select the CesiumWorldTerrain in the Outliner. Go to the Details panel \> Cesium \> Rendering \> Water Material. Assign the new **MI\_CesiumThreeOverlaysAndClippingAndWater** here.
7. Click Refresh Tileset multiple times. The ocean will turn white. If it doesn’t turn white, try editing the Georeference Origin a couple of times. The ocean will eventually turn white.

I tested this with UE 5.0.3, and this bug does not happen. Hoping to find a fix for UE 5.1.

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**Author:** ![Kevin\_Ring](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/kevin_ring/32/2003_2.png) [@Kevin\_Ring](https://community.cesium.com/u/Kevin_Ring)\
**Post date:** [January 10, 2023, 7:54am UTC](https://community.cesium.com/t/changing-water-material-in-ue-5-1-causes-ocean-to-turn-white/21894/2 "2023-01-10T07:54:34Z")

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I believe this is a bug in UE 5.1. More details here:

> [@Material Instance: Error: Too many texture coordinate sets defined on GPUSkin vertex input. Max: 4](https://community.cesium.com/t/is-cesiumgltffunction-broken/21693/7):
>
> Ok I can reproduce this in UE 5.1. And if I click “Platform Stats” while the material is open, UE reports: Which is very strange because “Used with Skeletal Mesh” is disabled, so I’m not sure why UE is concerned with any skinning. It may be a UE 5.1 bug, as it doesn’t seem to happen in UE 5.0. I’ve opened a ticket on UDN to ask for advice from Epic: [https://udn.unrealengine.com/s/question/0D54z00008dPGb6CAG/too-many-texture-coordinate-sets-defined-on-gpuskin-vertex-input-in-ue-51-bu…](https://udn.unrealengine.com/s/question/0D54z00008dPGb6CAG/too-many-texture-coordinate-sets-defined-on-gpuskin-vertex-input-in-ue-51-but-not-earlier-versions)