I'm a doctor, not a mechanic
- Replication – If set, then this actor is always relevant to gameplay. As a result, the server will always be keeping tabs on this actor and constantly sending data to its clients about it, regardless of any other circumstances. For example, ReplicationInfos are always relevant.
- If something attempts to teleport the actor, then the attempt will be successful. For example, this is True for Pawn (UT)s and False for Inventory (UT) items.
- When being placed using the editor, this actor will not allow itself to be moved through walls and other such things.
- An actor which has this flag set will display a directional arrow in UnrealEd when selected. This directional arrow matches the current setting of the actor's Movement -> Rotation property (see Actor (UT)/Movement). It also allows the actor to be rotated the same way as a brush in an UnrealEd Viewport (see Brush rotate). By default, Spotlights, PlayerStarts and some Decorations are directional, but Triggers and ordinary Light (UT)s are not.
Tip: Set this to True for brushes (including the red builder brush) to see whether they have rotation applied.
- In the editor, this actor should snap to the grid when it is being placed. This is set by default to True for Brushes and False for other actors. It's often useful to set this to True for actors such as Trigger or BlockAll, as they can then be aligned to the grid exactly. The value of this property determines whether an actor has a pivot.
- In stand-alone games, this actor can be forced into stasis when it doesn't need to be updated, even if it has physics is something more meaningful than simple rotation.
- This actor is relevant to gameplay. For example, this is True for such things as GameInfo (UT) and ReplicationInfo. If this is set to True mutators won't change or replace the actor.
- During the game, this actor should not be displayed. Obviously, things like Pawn (UT)s are not hidden, but Triggers (UT) are.
- In the editor, this actor should not be displayed. It's for instance used for the LevelInfo actor that is automatically added when you create a new map. (The LevelInfo actor's properties can be set with UnrealEd Main Menu -> View -> Level Properties)
Some mappers set this flag on the brushes in their levels. To reveal a brush that has been hidden like this, first find it in the Actor Search window. Double-clicking its name there will selected it even though it isn't visible in any UnrealEd Viewport. Then open the Actor Properties window (F4) and set this flag to False. The object in question should re-appear.
- This actor will only show up if the game is set to render high detail. This is typically used with SkyZoneInfo objects to provide two SkyBoxes. One used when high detail is set, and the other used when high detail is not set.
- This actor will count in the item count of some such mechanic. Inventory (UT) items are examples of this.
- This actor will count in the death tally. ScriptedPawns are examples of this.
- This actor will count in the list of secrets. I can't think of any examples of this that are used in Unreal or Unreal Tournament.
- This actor is not just stuck in place; it can move or be moved around the level. Some Decorations are movable and some aren't. NavigationPoints are never movable. Pawn (UT)s are almost always movable.
- Replication – In online games, it can sometimes be necessary to forego the replication of some relevant actors. In such a case, the list needs to be pruned further, and actors that are bNetOptional are of a type that should only be replicated to clients if there is enough bandwidth for it.
- Replication – Tear-off simulation in network play. When set to true, the actor and its variables are replicated only when it is first spawned. Thereafter everything is handled client-side – and no longer relevant to the server, which retains its own, game-relevant copy – thus preventing excessive bandwidth consumption. Generally used with actors which adhere to movement which can be predicted solely by standard physics types or client-side calculation (noncontrollable projectiles, decorations, effects).
- This actor cannot be deleted during play. For most actors, this is False. Pawn (UT)s, some Decorations, and Triggers (UT) can be deleted, but such things as Brushes and NavigationPoints should not be deleted.
- If an actor has an owner, then this owner is the only other actor that can see it.
- If an actor has an owner, then this owner is prevented from seeing the actor. This property is used for the ShieldBeltEffect, for instance.
- This actor is capable of entering stasis. In standalone games, an actor that doesn't need to be updated because of the player's location can enter stasis, especially if its physics is nonexistent or the actor is simply rotating in place.
- This actor doesn't move or change at all over the course of time. PathNodes are bStatic, for example, because they don't need to be updated during the game, thus saving processing resources.
Note: Neither Tick nor Timer are executed for bStatic actors.
Another Note: Never use this to prevent items from rotating. There's the bRotatingPickup property for a reason, so use it.
- This actor is capable of travelling between levels and between servers. This is pretty much only True for such things as PlayerPawns and Inventory (UT) items.
- This is a float that tells how many seconds the object gets to exist before it is automatically destroyed. Most actors have a LifeSpan of 0.0, which means that they are allowed to exist forever. However, some things such as Effects (UT) and Projectile (UT)s do have a definite LifeSpan.
Evilmrfrank: Ayone have any clue how to get the directional property to work in the classic UT? I have tried to use it a number of times but it never seems to work correctly.
Xian: From what I know, it's used by UED mostly to set the initial rotation of an actor (say the AmbushSpot). Tell me what you need/want to do and I'll do my best to explain it as clear as possible :)
Evilmrfrank: I have needed it for many things in UT from teleporters, to playerstarts, etc. According to this article you only need to change the setting to bdirectional=true, but that doesnt work.... I never see any red arrow like I do in Unreal Ed 3.0
Xian: Tried it on a weapon and the arrow appeared.