Downloaded Megascans assets cannot be accessed while offline

TM - Core - Mar 30, 2026

Reported in SF [Link Removed] When launching and using Twinmotion 2025.2 or 2026.1 offline, the Megascans library becomes unusable due to the subfolders of the 3D assets, 3D plants, Surfaces and De ...

Sphere Mask ArgInvHardness missing multiplication

UE - Rendering - Architecture - Materials - Jun 27, 2025

Hi Epic, In MaterialExpressions.cpp UMaterialExpressionSphereMask::Compile(), hardness is not calculated the same way in both <if> conditions. One is missing a multiplication by 0.01f. Specificall ...

360 videos with precipitation will get darker at times

TM - Rendering - Sep 19, 2025

Reported in SF [Link Removed] When exporting 360 videos with precipitation, there may be a noticeable darkening effect in the exported render that fades in and out. This effect is not present in th ...

Server RPC with struct param containing class reference does not pass parameter

UE - Networking - Apr 2, 2018

Class ref is not passed to server within the struct in UE 4.19. Instead, the default value is passed to the server. LogNetPackageMap: Warning: SanityCheckExport: CacheObject == NULL. NetGUID: 1, Ob ...

Fbx importer can import valid under 30Hz anim at 30Hz

Tools - Jul 17, 2017

The samplerate of a track was compute with the following formula Equation 1: number of Key / animation Time This formula work only if we have animation keys that are time equidistant. example of ...

Kinematic in Physics Asset Overrides Bone Scale of Skeletal Meshes

UE - Simulation - Physics - Oct 7, 2020

In a character's Physics Asset, a bone that is set to Kinematic and its children will have a scale of 1 overriding the Skeletal Mesh's Scale Transform settings. When the root of the body is changed ...

Rendered panoramas using Lumen may be overexposed

TM - Rendering - Sep 30, 2025

Reported in SF [Link Removed] Lumen Panorama renders in 2025.2 may appear overexposed compared to the viewport, or when comparing the same render produced in 2025.1.1 This only appears to occur wi ...

Translucent Materials no longer reflect light when using Forward Lighting variable

UE - Graphics Features - Jun 7, 2016

Translucent materials are no longer showing light reflections in scene when using r.forwardlighting 1 with lights. This is a regression from functionality in 4.11.2. This no longer works with 4.12 ...

Blendspace Animation Lag for Morph Targets

OLD - Anim - Sep 11, 2015

Blendspace animations of morph targets play at a slightly but noticably different rate between the 4.8 and 4.9 version of the UE4. ...

lots of wasted Volumetric lightmap samples

UE - Graphics Features - Lumen - Jun 20, 2019

Expectations: The samples should only surround the lightmass importance volumes.  Imagine if we build a 8K*8K map with lightmap importance volume at the corners of the map, even using stream levels ...