Actor Component properties can become "linked" across multiple Blueprints after a hot reload

UE - Gameplay - Components - Dec 3, 2018

If code in an Actor Component class is changed (eg. a new UPROPERTY is added) and a hot reload is performed to implement the changes, the properties in the component can become linked across any Blu ...

The "Random Integer in Range from Stream" returns the same value if the seed is power of 2 of anything above 22.

UE - Foundation - Core - Aug 7, 2019

When using the "Random Integer in Range from Stream" where the seed is a power of 2 after a certain point (2^22) the random integer that is returned is the always the same. If the seed is 2^23 + 1 i ...

When very far out from the map origin, large static mesh is not streaming in until player is close in world partition even though it's within loading range.

UE - World Creation - Worldbuilding Tools - World Partition - May 7, 2025

Context World Partition has a distance-based level streaming system that provides a complete solution for large world management. Problem The problem is that when the player and large static mesh a ...

Child actor passes a string to it's parent's overloaded constructor the incorrect string is received

UE - Gameplay - Sep 24, 2019

When a child actor passes a string to it's parent's overloaded constructor using an overridden function that returns a string it won't receive the correct string. I have verified that the correct fu ...

Costs of Static Lights on Render Thread

UE - Graphics Features - Jun 9, 2016

A Japanese developer's making a scene that has over 4000 static point lights. They thought the lights don't affect rendering in runtime. But they realized the RenderThread's costs become bigger. I ...

Vulkan leaks memory when opening and closing windows

UE - Rendering Architecture - RHI - Nov 22, 2019

As described here: https://udn.unrealengine.com/questions/532725/index.html (1) Start Prebuilt Vanilla 4.23.1. with Vulkan enabled (2) Create a new project (3) Drag and drop the Sphere from “modes ...

Android compile failure with GearVR

UE - Platform - XR - Jul 11, 2017

Compiling failure from several compile errors in the output log. They're of same type like this:UATHelper: Packaging (Android (ETC2)): xgConsole: In file included from D:\Streams\UE4_Release\Engine\ ...

Crash when Applying Hole Material to Imported Tiled Landscape with World Composition

UE - LD & Modeling - Terrain - Landscape - Jun 11, 2015

A crash occurs when importing a tiled landscape, via the 'Levels' window with World Composition enabled, and applying a material to the 'Hole Material' slot. You can also re-apply a default material ...

Package build fails after disabling VR plugins

UE - Platform - XR - Mar 27, 2017

Package build fails after disabling VR plugins and launching the project The error message that pops up is: Fatal error: [Link Removed] [Line: 353] Missing global shader FPixelShaderDeclaration, P ...

Audio Components ignoring Start Time set by Play node on Android

UE - Audio - Jul 15, 2015

Setting the start time within the Play node for an audio component does not function when deploying to Android. The set up works fine when playing on the PC, and the sound functions on the Android ...