How to use glPolygonOffset inside fragmentShader to reduce z-fighting

CesiumJS
4

I’m actually not able to activate shadows with Cesium OSM Buildings. I get the following error:

DeveloperError: normalized result is not a number
Error
    at new DeveloperError (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:83:13)
    at Function.Cartesian3.normalize (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:2040:13)
    at Ellipsoid.geodeticSurfaceNormal (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:3601:23)
    at Ellipsoid.cartesianToCartographic (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:3694:18)
    at fitShadowMapToScene (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:266739:40)
    at ShadowMap.update (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:266971:9)
    at updateShadowMaps (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:282471:17)
    at updateAndRenderPrimitives (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:282494:5)
    at executeCommandsInViewport (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:282266:7)
    at Scene.updateAndExecuteCommands (https://sandcastle.cesium.com/CesiumUnminified/Cesium.js:282009:7)

Sandcastle I’m testing with. Do you not get this error when activating shadows? If so, can you share a Sandcastle of how you’re initializing your scene?