XML Modding ‐ Level Patching

Level Patching

Chairloader has special handling for level objects in mission_mission0.xml file.

Automatic GUID Generation

There are two major types of level objects: entities and non-entities. Entities have EntityGUID attribute (random 64-bit ID in hex). Non-entities don't have that attribute.

Chairloader automatically generates EntityGUID for non-entity objects and sets ch:fakeGuid="true" attribute. After all mods are merged, auto-generated GUIDs are removed from the file.

Automatic EntityID Generation

Each level entity must have a unique EntityId attribute, which is a sequential 16-bit integer. To prevent conflicts between mods, Chairloader mods are not allowed to specify EntityId at all. After all mods are merged, Chairloader automatically assigns Entity IDs to mod entities.

Sometimes you need to know the Entity ID in the XML (e.g. to reference it from a flowgraph). Use values in the format $(EntityId:[guid]) to reference an entity. This format only works in mission_mission0.xml and only references the entities in this file.

<EntityLinks>
    <Link
        TargetId="$(EntityId:409E604DF4F0F65F)"
        Name="NewLink" />
</EntityLinks>

Automatic serialize.xml generation

serialize.xml lists the entities that must be serialized (written in the game's save file). serialize.xml references them by EntityId. Since EntityIDs are assigned by Chairloader, mods can't modify this file. Instead, set ch:serialize="true" attribute on entities that you wish to serialize. After all mods are merged, Chairloader will generate serialize.xml for each level based on ch:serialize values.