Merge pull request #1680 from CesiumGS/null-georeference-checks

Fix crash that results from duplicating a georeference

Author: kring

CHANGES.md

@@ -10,7 +10,8 @@
 
 - Worked around an Unreal Engine limitation that prevented collisions and line traces from working correctly for tilesets with a very small scale factor.
 - Add a missing include for `GEngine` when packaging from source, introduced in *v2.16.0*.
-- Fixed a bug in UCesiumFeaturesMetadataComponent where multiple references to same feature ID set would cause improper encoding of its feature IDs.
+- Fixed a bug in `UCesiumFeaturesMetadataComponent` where multiple references to same feature ID set would cause improper encoding of its feature IDs.
+- Fixed a crash that would occur when duplicating an `ACesiumGeoreference`.
 - Removed an unnecessary copy operation that happened while constructing tile meshes.
 
 ### v2.16.0 - 2025-05-01

Source/CesiumRuntime/Private/Cesium3DTileset.cpp

@@ -232,17 +232,20 @@ ACesiumGeoreference* ACesium3DTileset::ResolveGeoreference() {
         ACesiumGeoreference::GetDefaultGeoreferenceForActor(this);
   }
 
-  UCesium3DTilesetRoot* pRoot = Cast<UCesium3DTilesetRoot>(this->RootComponent);
-  if (pRoot) {
-    this->ResolvedGeoreference->OnGeoreferenceUpdated.AddUniqueDynamic(
-        pRoot,
-        &UCesium3DTilesetRoot::HandleGeoreferenceUpdated);
-    this->ResolvedGeoreference->OnEllipsoidChanged.AddUniqueDynamic(
-        this,
-        &ACesium3DTileset::HandleOnGeoreferenceEllipsoidChanged);
-
-    // Update existing tile positions, if any.
-    pRoot->HandleGeoreferenceUpdated();
+  if (this->ResolvedGeoreference) {
+    UCesium3DTilesetRoot* pRoot =
+        Cast<UCesium3DTilesetRoot>(this->RootComponent);
+    if (pRoot) {
+      this->ResolvedGeoreference->OnGeoreferenceUpdated.AddUniqueDynamic(
+          pRoot,
+          &UCesium3DTilesetRoot::HandleGeoreferenceUpdated);
+      this->ResolvedGeoreference->OnEllipsoidChanged.AddUniqueDynamic(
+          this,
+          &ACesium3DTileset::HandleOnGeoreferenceEllipsoidChanged);
+
+      // Update existing tile positions, if any.
+      pRoot->HandleGeoreferenceUpdated();
+    }
   }
 
   return this->ResolvedGeoreference;

Source/CesiumRuntime/Private/Cesium3DTilesetRoot.cpp

@@ -62,10 +62,12 @@ void UCesium3DTilesetRoot::_updateAbsoluteLocation() {
 
 void UCesium3DTilesetRoot::_updateTilesetToUnrealRelativeWorldTransform() {
   ACesium3DTileset* pTileset = this->GetOwner<ACesium3DTileset>();
+  ACesiumGeoreference* pGeoreference = pTileset->ResolveGeoreference();
 
-  this->_tilesetToUnrealRelativeWorld = VecMath::createMatrix4D(
-      pTileset->ResolveGeoreference()
-          ->ComputeEarthCenteredEarthFixedToUnrealTransformation());
+  if (pGeoreference) {
+    this->_tilesetToUnrealRelativeWorld = VecMath::createMatrix4D(
+        pGeoreference->ComputeEarthCenteredEarthFixedToUnrealTransformation());
 
-  pTileset->UpdateTransformFromCesium();
+    pTileset->UpdateTransformFromCesium();
+  }
 }