Slate and UMG performance profiling
The Widget Profiler measures live widget paint and prepass CPU time, update activity, invalidations, emitted draw elements, and geometry changes. It supports inspection through authored UMG hierarchies or native Slate hierarchies, with widget picking and highlighting.
Find and inspect work
Section titled “Find and inspect work”Ranked diagnostic findings help locate widgets worth investigating. Material and resource inspection, including compiled material statistics, provides context for the assets involved in rendering the interface.
Paint and prepass are distinct CPU phases. Keep that distinction when interpreting a finding or comparing two captures.
Capture and compare
Section titled “Capture and compare”The profiler includes rolling history, persistent captures, recoverable sessions, and regression comparisons. JSON/CSV export and Unreal Insights trace integration support further analysis and sharing results.
Use repeatable UI states when comparing captures. Open the same interface, exercise the same interaction, and review the affected hierarchy and measurements together.
Editor and in-game surfaces
Section titled “Editor and in-game surfaces”A dedicated editor window and in-game panels share the profiler. Collection is opt-in and is unavailable in Test and Shipping builds.
Enable collection for the investigation, reproduce the relevant UI state, and record the context needed to understand the capture later.
Measurement boundaries
Section titled “Measurement boundaries”The profiler does not assign GPU time or exact Blueprint execution time to individual widgets. Emitted draw elements and compiled material statistics are useful evidence, but they are not per-widget GPU timings.
Use the measured CPU phases to assess widget work, and use the additional resource and activity data to guide the next investigation. Treat a diagnostic finding as evidence to inspect, not proof of a specific performance improvement.
Retained rendering controls and custom widgets are still being implemented and validated. Their performance benefits remain subject to comparison and measurement.