The Decal Manager is responsible for managing the spawned decals. The number of decals can be capped at a limit to prevent too many from being spawned. The decals can then slowly be faded (weathered) for a smooth transition rather than the decal just popping out of existence.
The maximum number of decals that can spawn. As new decals appear the older ones are weathered and eventually remove.
Weathered Decal Limit
Specifies how many of the oldest decals will be gradually faded away a tiny bit each time a new decal is spawned. The oldest of the decals will be almost invisible before it is removed.
Weathering is based on the number of decals in the scene and the order in which the decals were created rather than on game time. Every time a new decal is placed the oldest of the decals will be weathered. If no decals are placed and a decal is 50% weathered then it will stay in the world indefinitely.
Remove Fadeout Speed
The speed that the decals should fadeout after they have been removed from being weathered.