Cesium TMS Raster Overlay missing tiles rendered as white instead of transparent

Cesium for Unity
1

Hello,

I am using Cesium Tile Map Service Raster Overlay in Unity with local PNG tiles.

The problem is:

  • Areas where PNG tiles do not exist are rendered as white.
  • I want missing tile areas to be transparent, or filled with another color instead of white.

I tried:

  • Changing Material Key
  • Custom Opaque Material
  • Transparent material/shader settings

Additionally, I opened the “CesiumDefaultTilesetMaterial” (Shader Graph) included in the Cesium for Unity package, modified the shader logic to set the Alpha value to 0 for those regions, and assigned this custom material to the Opaque Material slot of the Cesium 3D Tileset component. However, even after doing this, the missing tile areas are still rendered as solid white.

Is there a supported way to:

  1. Make missing TMS tiles transparent?
    or
  2. Change the fallback color for missing tiles?

Thank you.