tvOS crash on startup with Shared Material Shader Code enabled

UE - Platform - Mobile - Jul 9, 2019

Enabling Shared Material Shader Code will cause a crash on tvOS From user: "We originally enabled Share Material Shader Code long before trying a tvOS build, making this crash tricky to debug. W ...

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 ...

Masked TwoSided material causing lumen direct lighting to leak through walls

UE - Graphics Features - Lumen - Apr 23, 2024

It appears that LumenScene's Hardware Ray Tracing is causing light leaking into a sealed room (which should be perfectly black). This bug does not appear to happen on AMD GPUs. ...

High Virtual Texture Sample/Lookup Cost when using a Virtual Texture in a Material Layer Blend

UE - Rendering Architecture - Materials - Mar 14, 2025

Some Material Attribute blends in Material Layer Blends can cause Virtual Texture samples to be duplicated in HLSL. This can be avoided by sampling the Virtual Texture in the Parent Material, and pa ...

Packed level actors and Level instances are sometimes not included in HLOD build on a World Partition Level

UE - World Creation - Worldbuilding Tools - HLOD - Mar 14, 2025

Context World Partition - Hierarchical Level of Detail (HLOD) system uses custom HLOD Layers to organize large amounts of Static Mesh Actors and generate a single proxy mesh and Material. Problem T ...

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 ...

PhysX generates extra "sleep" event when moving Kinematic actors away from Simulated actors with Teleport option.

UE - Simulation - Physics - Aug 4, 2016

Issue seems to be related to NpRigidDynamic::setKinematicTarget. When called by itself (like in the case of Kinematic bodies moved without teleportation), the simulated actor is woken and is put ba ...

Orthographic Camera view doesn't work with movable directional light shadows and partly with stationary shadows

UE - Graphics Features - Feb 26, 2015

See attached video for clear examples. When using the orthographic camera perspective with default light settings to stationary for directional light source. Other light sources work as intended. T ...

Actor with Camera Component UProperty causes ensure when PIE ends if replicating

UE - Networking - Nov 17, 2015

If an Actor with a CameraComponent is set to replicate, ending a PIE session with 2 players will result in an ensure ...

Particle record in the Matinee leads to crash when playing after record.

Tools - Oct 19, 2017

Particle record feature in the matinee seems not properly working in the Editor. When trying to play in the matinee with recorded keys, the Engine will crash with Access violation - code c0000005. ...