UE4 itself defines several logging categories, including categories such as LogActor, which has any log messages to do with the Actor class, and LogAnimation, which logs messages about animations. In general, UE4 defines a separate logging category for each module. This allows developers to output their log messages to different logging streams. Each log stream's name is prefixed to the outputted message, as shown in the following example log messages from the engine:
LogContentBrowser: Native class hierarchy updated for
'HierarchicalLODOutliner' in 0.0011 seconds. Added 1 classes and 2
folders. LogLoad: Full Startup: 8.88 seconds (BP compile: 0.07 seconds) LogStreaming:Warning: Failed to read file
'../../../Engine/Content/Editor/Slate/Common/Selection_16x.png'
error. LogExternalProfiler:...