Crash when rendering cinematic in a Separate Process without "-NoLoadingScreen" cmd argument

UE - Anim - Sequencer - Jul 5, 2016

Crash when rendering cinematic in a Separate Process without "-NoLoadingScreen" cmd argument. Occurs in 4.12 and 4.13 in both Matinee and Sequencer Error message: Assertion failed: SizeX > 0 && S ...

FBX export from UE4 with multiple materials the UV is corrupted

Tools - Apr 18, 2016

When exporting a Static Mesh from within UE4 that has multiple materials, some of the material IDs will be condensed into a single ID which will mess up how the material assignment for that part of ...

Manually importing LODs are rotated 90 degrees when using Transform Vertex to Absolute

Tools - May 26, 2016

When importing a Static Mesh if you use the default settings and then manually import any LODs for that static mesh they will be rotated by 90 degrees. I found that disabling Transform Vertex to A ...

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 ...

Does Container Match Tag Query Node doesn't find existing Gameplay Tags in Packaged Project with Nativized Blueprints

UE - Gameplay - Aug 26, 2019

When using the "Does Container Match Tag Query" node doesn't return true when a gameplay container member has the searched for gameplay tag in a blueprint that has been nativized. Packaging in Excl ...

Plane Constraint Normal is not Properly Reset

UE - Simulation - Physics - Jan 26, 2016

In the Character Movement Component, setting the Plane Constraint Normal to a value other than default, and then attempting to change the value back to the default does not revert to the default val ...