https://github.com/sideeffects/HoudiniEngineForUnity/blob/01ad527fa9d1f3f7a65c347fa48727b7b6aeb749/Plugins/HoudiniEngineUnity/Scripts/Asset/HEU_InputNode.cs#L268-L279 [github.com]
AddInputEntryAtEnd() always return null.
This line will crash because it references to a null object:
https://github.com/sideeffects/HoudiniEngineForUnity/blob/01ad527fa9d1f3f7a65c347fa48727b7b6aeb749/Plugins/HoudiniEngineUnity/Scripts/Utility/HEU_ShelfTools.cs#L586 [github.com]
I realised it when I after a copy of the code in ExecuteToolOperatorSingle() and use it to pass GameObject to HDA. I'd like to know whether it's a bug or I've misunderstood the code.
The fix is trivial:
public HEU_InputObjectInfo AddInputEntryAtEnd(GameObject newEntryGameObject) { if (_inputObjectType == InputObjectType.UNITY_MESH) { return InternalAddInputObjectAtEnd(newEntryGameObject); } else if (_inputObjectType == InputObjectType.HDA) { return InternalAddInputHDAAtEnd(newEntryGameObject); } return null; }