I am trying to cut out a polygon using global transparency. I have a rectangle cut out at the moment but I want the area cut out to be a more specific polygon shape that I have also coded into the project. The current solution that I have come up with is making a rectangle with the hole of the polygon cut out over the rectangle that has global transparency applied to it. Now I am attempting to try to apply a material to the rectangle with the hole to match the surround map. Could anyone provide me advice on how to add the same Cesium World Terrain as a material to the polygon or how to use global transparency to just cut out a polygon area rather than the rectangle.