Changes from review.

Author: kring

CHANGES.md

@@ -5,6 +5,8 @@
 ##### Additions :tada:
 
 - Added support for rendering glTFs with line primitives.
+- Added `UCesiumGoogleMapTilesRasterOverlay`.
+- Added `AssetOptions` property to `UCesiumIonRasterOverlay`.
 
 ### v2.19.1 - 2025-09-02
 

Source/CesiumRuntime/Private/CesiumGoogleMapTilesRasterOverlay.cpp

@@ -108,6 +108,11 @@ JsonValue::Array getStyles(const TArray<FString>& styles) {
 std::unique_ptr<CesiumRasterOverlays::RasterOverlay>
 UCesiumGoogleMapTilesRasterOverlay::CreateOverlay(
     const CesiumRasterOverlays::RasterOverlayOptions& options) {
+  if (this->Key.IsEmpty()) {
+    // We must have a key to create this overlay.
+    return nullptr;
+  }
+
   return std::make_unique<CesiumRasterOverlays::GoogleMapTilesRasterOverlay>(
       TCHAR_TO_UTF8(*this->MaterialLayerKey),
       CesiumRasterOverlays::GoogleMapTilesNewSessionParameters{