Hey! I was wondering if there is a way to mask under a bridge for example, or is it only top down masking?
I am trying to mask water under a bridge without masking out the whole bridge.
Thank you!
You would probably run your mask to map the water and then place a static mesh bridge over it.
As far as I am aware, you can’t exclude something from the mask that is above or below the mask.
Cartographic Polygons are a 2D mask draped over the 3D geometry, so it’s generally not possible to exclude the area under a bridge but not the bridge itself, assuming both are part of the same tileset.
You might be able to use a trick. Cesium for Unreal’s materials use Material Layers. The Cartographic Polygon-based clipping system uses a layer named “Clipping”, with a blend function that sets the “Opacity Mask” to zero inside the polygon. If you wanted to exclude all parts of the tileset that are inside a polygon and below a particular height, you could do that by creating a custom material with a different blend function. The blend function would have custom logic to check the height in addition to the mask value coming from the polygon. You’ll need to turn off “Exclude Selected Tiles” on the CesiumPolygonRasterOverlay to prevent the entire tile from be excluded before the material can see it.
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