Required reading: NetworkObject Parenting
Before detailing Boss Room’s approach toon
NetworkObject parenting, it’s important to highlight a limitation of Netcode: A dynamically-spawned
NetworkObject cannot contain another
NetworkObject in its hierarchy. If you spawn such a
NetworkObject, you cannot spawn children
NetworkObjects. You can only add children
NetworkObject components to a
NetworkObject that is part of a scene.
Boss Room leverages
NetworkObject parenting through the server-driven
PickUp action (see
PickUpAction.cs), where a character has the ability to pick up a specially-tagged, in-scene placed
At its root,
PickUpPot contains a
NetworkTransform, and a
AutoObjectParentSync is enabled on its
NetworkTransform (as is by default) so that:
NetworkObjectcan verify server-side if parenting a Heavy object to another
NetworkObjectcan notify us when the parent has successfully been modified server-side.
To accommodate the limitation highlighted at the beginning of this document, Boss Room leverages the
PositionConstraint component to simulate an object following a character’s position.
A special hand bone has been added to our Character’s avatar. Upon a character’s successful parenting attempt, this special bone is set as the
PositonConstraint target. So while the
PickUpPot is technically parented to a player, the
PositionConstraint component allows the
PickUpPot to follow a bone’s position, presenting the illusion that the
PickUpPot is parented to the player’s hand bone itself.
PickUpPot is parented, local space simulation is enabled on its