ConstructionCreationMessage

Vanilla ProcessedMessage<ConstructionCreationMessage> at Assets.Scripts.Networking.ConstructionCreationMessage. The client-to-server message that requests construction of a Structure when the client is not the simulation owner. Carries the placement Quaternion losslessly via two WriteQuaternion slots.

Wire format

public class ConstructionCreationMessage : ProcessedMessage<ConstructionCreationMessage>
{
    public int PrefabHash { get; set; }
    public Vector3 WorldPosition { get; set; }
    public Quaternion WorldRotation { get; set; }
    public Quaternion LocalRotation { get; set; }
    public ulong OwnerClientId { get; set; }
    public Grid3 LocalGrid { get; set; }
    public int CustomColorIndex { get; set; }
}

Serialize / Deserialize in order:

public override void Serialize(RocketBinaryWriter writer)
{
    writer.WriteInt32(PrefabHash);
    writer.WriteVector3(WorldPosition);
    writer.WriteQuaternion(WorldRotation);
    writer.WriteQuaternion(LocalRotation);
    writer.WriteUInt64(OwnerClientId);
    writer.WriteGrid3(LocalGrid);
    writer.WriteInt32(CustomColorIndex);
}

public override void Deserialize(RocketBinaryReader reader)
{
    PrefabHash = reader.ReadInt32();
    WorldPosition = reader.ReadVector3();
    WorldRotation = reader.ReadQuaternion();
    LocalRotation = reader.ReadQuaternion();
    OwnerClientId = reader.ReadUInt64();
    LocalGrid = reader.ReadGrid3();
    CustomColorIndex = reader.ReadInt32();
}

Both rotations use the full 16-byte float-quaternion encoding (no half-precision, no axis-angle compaction). Any Quaternion the client computes - including non-cardinal, non-floor placements - survives the round-trip exactly.

Server handler

public override void Process(long hostId)
{
    base.Process(hostId);
    OnServer.Create<Structure>(PrefabHash, WorldPosition, WorldRotation).SetStructureData(LocalRotation, OwnerClientId, LocalGrid, CustomColorIndex);
}

Mirrors the in-process simulation path in Constructor.SpawnConstruct: the server resolves the prefab by hash, instantiates with the world Quaternion, and writes the LocalRotation Quaternion into the new structure's Direction field via SetStructureData. No server-side validation of rotation; whatever the client sent lands on the spawned Structure.

CreateStructureInstance (companion)

Assets.Scripts.Networking.CreateStructureInstance is the in-process placement-intent struct used by Constructor.SpawnConstruct and as the source of the ConstructionCreationMessage payload.

public class CreateStructureInstance
{
    public Grid3 LocalGrid;
    public Quaternion LocalRotation;
    public Structure Prefab;
    public GridController GridController;
    public int CustomColor = -1;
    public ulong OwnerClientId;

    public Vector3 WorldPosition => GridController.LocalToWorld(LocalGrid);
    public Quaternion WorldRotation => LocalRotation;

    public CreateStructureInstance(Structure prefabToCreate, Structure oldPrefab) { /* ... */ }
    public CreateStructureInstance(Structure prefabToCreate, Grid3 localGrid, Quaternion worldRotation, ulong ownerClientId, int colorIndex = -1) { /* ... */ }
}

Note: the public-facing WorldRotation getter returns LocalRotation directly. The two fields are aliased; there is no separate "local-relative-to-something-else" rotation in this struct. The caller passes a single Quaternion; both WorldRotation and LocalRotation channels of the message carry the same value.

Verification history

• 2026-04-25: page created from a six-agent decompile pass on the placement pipeline. Source content lifted verbatim from /tmp/decompile_check/Assets/Scripts/Networking/ConstructionCreationMessage.cs and CreateStructureInstance.cs. No conflicts.

Open questions

None.