Using Ghostmappings
Unreal Engine allows developers to talk to and use different assets and objects using code or blueprints. For example, a developer can reference the player's playerobject and get their position in the world.
The situation for modders however is different: we don't have the objects from VotV in our projects. So, how do reference things like props, players, and entities when modding? This is where ghost mappings come in.
What are ghostmappings
Ghostmappings are a collection of empty assets you add to your Unreal project that mimic the original asset files in VotV's project. They exist in the same place as the original asset, and also often include the same variables and functions that are in the original asset. These ghost assets do not have any code and do nothing on their own but allow developers to reference them and their variables in their code.
These ghost assets are not to be included in the packaged mod. When the packaged mod is loaded into VotV, any code that was previously accessing any ghost assets will instead end up referencing the real assets within the game. This is how modders are able to manipulate VotV's in-game assets and entities.
Installing ghostmappings
Make sure your Unreal Engine project is closed while making these changes.
Currently, the ghostmappings by ModestImpala are recommended. They can downloaded by clicking the code button, and clicking "Download Zip". Head into your Unreal Project's folder, and unpack the contents of the Content folder into the Content folder of your project.