Here are two methods to get variables to be global in Unreal.
First Method using a Game Instance — advantage = works between levels
Second Method using a Material Parameter Collection — advantage = Quicker to set up
1. Game Instance Method
Make a Blueprint of type GameInstance. (NOT GAME MODE)
You need to set your level to use this game instance in Project Settings /Maps and Modes/ Game Instance/ Game Instance Class to <YourGameInstance> (NOT GAME MODE)
Then open the game instance up and add some variables.
To access these variables to either get or set them, in another blueprint you need to Get Game Instance and then Cast To <YourGameInstanceName> (mine is called WeatherComntrol.)
Pulling a wire from the Blue output dot you should see under Variables/Default <Your VariableNames> that you can either get or set. Here I’m getting a float and a interger
2. Material Parameter Collection
Typically, Material Parameter Collections serve the purpose of sharing values among materials. For instance, let’s consider a scenario where multiple objects within a level should turn red under a specific condition, for example, when the user hits the space bar. By utilising the same Material Param Collection across different materials, any change in colour would affect all the materials using it, resulting in a simultaneous colour change across those materials. We can use the Material Parameter Collection to store and retrieve multiple scalars and vectors, and we can use these values in other places besides materials.
To do it, first R-click in the content browser and make a material parameter collection and give it some values.
Then in any blueprint, you can set or get the named parameter. You can use it to change values in materials or anything else or vice versa.
