Unreal Engine Unreal Engine Performance Optimization & Profiling

Question 1

Which Unreal Engine built-in tool provides a hierarchical CPU and GPU timing breakdown of a single frame to identify performance bottlenecks?

Accepted Answer

Unreal Insights (Session Frontend)

Answer

Stat Unit

Answer

RenderDoc integration

Answer

GPU Visualizer

Question 2

What does the console command `stat fps` display in Unreal Engine?

Accepted Answer

Current frames per second and frame time in milliseconds

Answer

GPU memory usage per render pass

Answer

Number of draw calls per frame

Answer

Active particle count in the scene

Question 3

What is the purpose of Level of Detail (LOD) meshes in Unreal Engine?

Accepted Answer

Swap high-poly meshes for lower-poly versions as the camera distance increases

Answer

Generate collision shapes automatically from mesh geometry

Answer

Reduce texture resolution on mobile platforms

Answer

Merge multiple meshes into a single draw call

Question 4

Which Unreal Engine feature automatically merges nearby static mesh draw calls into a single draw call to reduce CPU rendering overhead?

Accepted Answer

Instanced Static Meshes (ISM / HISM)

Answer

Nanite virtualized geometry

Answer

Distance Field Ambient Occlusion

Answer

Mesh Draw Policy

Question 5

What does the Unreal Engine console command `r.ScreenPercentage 50` do?

Accepted Answer

Renders the scene at 50% of the screen resolution then upscales

Answer

Limits the frame rate to 50 FPS

Answer

Reduces texture streaming pool to 50%

Answer

Sets the LOD bias to reduce mesh detail by 50%

Question 6

In Unreal Engine, what is 'occlusion culling' and why is it used?

Accepted Answer

Skipping rendering of objects hidden behind other geometry to save GPU cost

Answer

Removing objects outside the camera frustum

Answer

Merging transparent objects into a single render pass

Answer

Hiding actors beyond the far clip plane distance