Unreal Engine Issues
Unreal Engine Issues
Video material broken on Mac M3+ (sm6)
TM - Rendering - Oct 21, 2025On Mac devices, the video material in the viewport will display incorrectly, appearing stretched significantly. This only seems to affect the viewport and not rendered exports. ...
Material expression "FloatToUInt" can trigger a check() when input is invalid
UE - Rendering - Architecture - Materials - Mar 11, 2026When a "Float to UInt" Expression is used in a Material Graph with a valid direct input connection that fails to evaluate, function UMaterialExpressionFloatToUInt::Compile() does not catch the input ...
Cascade ParticleRelativeTime Outputs Constant 0 on Mobile
UE - Niagara - Aug 29, 2018Cascade ParticleRelativeTime outputs constant 0 on mobile. Found in 4.19 CL# 4033788, 4.20 CL# 4302132, 4.21 CL# 4321618 ...
Recent change to Material Expression code missing a case for "exp2" function in switch (cpp)
UE - Editor - Content Pipeline - Datasmith - Mar 4, 2024The function "FMaterialDerivativeAutogen::GetFunc1ReturnType(...)" does not have a case for "EFunc1::Exp2". Also found in Release-5.4, CL: 331987674 ...
Vertex Interpolate Node Doesn't Work with Lightmass
UE - Graphics Features - Lumen - Aug 8, 2018The vertex interpolate node doesn't work with lightmass. Found in 4.19 CL# 4033788, 4.20 CL# 4233996, and 4.21 CL# 4258917 ...
Updating a material layer may not update materials that are using that material layer instance
UE - Rendering - Architecture - Materials - Jan 7, 2022Material layer instances do not generate a valid UMaterialFunctionInterface::StateId. For this reason, materials and material instances that use material layer instances will not recompile their sh ...
Particle LODs Does Not Use Assigned Mesh For Mesh Data Module
UE - Graphics Features - Oct 5, 2016When making an LOD for a particle system in cascade the higher level LODs won't change their assigned mesh. In the attached project I'm using stairs for the LOD0 mesh and a rectangular Mesh for LOD1 ...
Copy Procedural Mesh from Static Mesh Component does not work correctly when the order of material slots is different
UE - Graphics Features - Oct 15, 2019This issue occurs when the section and material slot order do not match In this sample project:[Link Removed] According to a report from the licensee, the order of Sections seems incorrect.[Link R ...
StartCameraFade not fading camera
UE - Platform - Mobile - Aug 3, 2016This started happening recently in 4.13 integrations. StartCameraFade node no longer has any effect. Fading no longer works in new VR Template. ...
Epic Mannequin's Material Does Not Render Correctly On Intel HD Graphics
UE - Graphics Features - Feb 1, 2017The Epic Mannequin no longer renders correctly when using an Integrated Intel HD Graphics 4600 GPU. The character will either have parts of his body hidden(4.14) or completely black(4.15) depending ...