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 ...

Importing a t3d filetype will cause a crash

UE - Editor - Content Pipeline - Import and Export - Jun 15, 2016

!!! Changes between version 4.12 and 4.13 for importing these !!! 4.12 There is a crash when importing any t3d (legacy) file through File > Import Into Level using the t3d file option. 4.13 The ...

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 ...

Scalar Parameter versus Constant placed in Alpha of LERP produces inconsistent results in Blendable

UE - Graphics Features - Jun 8, 2015

When placing a Scalar Parameter into the Alpha position of a LERP you will not get the same results as placing a Constant Value when used in a Post Process Material. Constant Value of 0: [Image Rem ...

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 ...

FBX Export - StaticMesh export to FBX crashes if UVElements has more channels than VertexInstanceUVs

UE - Editor - Open File Formats - FBX - Jan 22, 2026

As indicated in the repro steps, we have a StaticMesh asset that, for some reason, has a mismatch in their serialized bulk data where:MeshDescription->GetNumUVElementChannels() == 2FStaticMeshConstA ...