FCanvasTriangleRendererItem relies on BaseVertexIndex not being zero.

UE - Rendering Architecture - RHI - May 20, 2019

The root of this issue is that FLocalVertexFactory is doing manual vertex fetch in the shader. In HLSL, this relies on SV_VertexId. In GLSL, it's gl_VertexId. HLSL does not include the base vertex i ...

External textures only work in pixel shaders

UE - Platform - Mobile - Nov 21, 2017

External textures currently only support pixel shaders, presumably because some platforms, such as Android only have pixel shader support. On other platforms this causes a regression though: For exa ...

Massive FPS drops in editor when moving mouse over menu items on Linux

UE - Platform - Linux - Apr 22, 2019

Navigating various dropdown menus in the Editor causes the FPS to drop down to around 25 or 10 in the Viewport on an empty project. This does not reproduce on Windows with -vulkan This issues was ...

Assertion at "UnrealInsights-TraceAnalysis.dll!UE::Trace::FTidPacketTransport::ReadPacket" when opening a capture file from a PS5 Dev Client with an Insights Binary

UE - Foundation - Insights - Jan 24, 2023

NOTES See Slack Thread for more Info: [Link Removed] 7Z file: [Link Removed]  PLATFORMS TESTED PC: Not tested Xbox One: Not tested XSX: Not tested PS4: Not tested PS5: Occurs Android: Not tested S ...

Shader compilation errors when packaging for iOS after disabling force full precision

UE - Platform - Mobile - May 29, 2024

User report: I want to run iOS shaders with half precision floats as I do on Android. If I disable Force 32 bits Floating Point Precision, there are unfortunately a bunch of shader compilation error ...

Crash in FLandscapeRenderSystem on Mobile

UE - Graphics Tools - Terrain - Landscape - Aug 4, 2021

Similar issues have already been reported here for iOS [https://udn.unrealengine.com/s/question/0D52L00004vJelTSAS/crash-ios-in-flandscaperendersystemcomputesectionperviewparameters] and here [https ...

Landscape is missing its material when running a packaged project on Linux arm 64

UE - Graphics Tools - Terrain - Landscape - Apr 22, 2024

From licensee: The project contains a small flat terrain with a basic material attached to it - just a single texture sampler connected to the base color output. Also in the project is a skeletal m ...

Painted Landscapes have blacked out sections when deployed to a mobile device

UE - LD & Modeling - Terrain - Landscape - Mar 24, 2015

If a user uses a multi layered material to pain a landscape and then deploys this project to an iPhone 6 plus our an Android Samsung Galaxy Note3 (SM-N9005) parts of the landscape will appear to be ...

Unable to compile Runtime plugins

UE - Foundation - Cpp Tools - Plugin System - Jun 27, 2018

Attempting to package a runtime plugin in 4.20 results in the following error: ERROR: System.IO.DirectoryNotFoundException: Could not find a part of the path 'D:\Unreal Projects\4.20\PluginTest\Test ...

SessionFrontend Causes Lost Audio on iOS After Switching Apps

UE - Audio - Oct 20, 2020

When using SessionFrontend on some devices, when leaving the app (going to the home screen or another app) or sometimes locking the device there is no more audio after returning to the game. "It lo ...