101.1 Point Release


  • Source code included to allow source builders of Unreal Engine to use the plugin.

  • USD Skeletal Mesh import improvements to support more USD hierarchies

  • Fixed Skeletal Mesh material editing in live-sync

  • Added support for exporting IOR values in MDL with Unreal Ray Tracing Translucency

  • Fixed many custom HLSL material expression issues for MDL export

  • Add import and live-sync support for USD DomeLights as UE4 sky sphere actors.


  • Include source code in the Launcher download to support GitHub Unreal Engine source builds

Bug Fixes

  • Materials

    • Fix an issue where an MDL parameter name might be redefined, causing invalid materials (OM-29128)

    • Fix an issue where deleting a material made in Create while in a live sync session didn’t update in Unreal (OM-28940)

    • Fix missing parameter annotations from parameters in material functions

    • Fix live editing of materials in a skeletal mesh (OM-29530)

  • USD importer will convert mesh from Y-up to Z-up, so cache should be changed if the up-axis is different (OM-29351)


  • Materials

    • Add support for Unreal’s combined material and post process volume ray tracing translucency in transparent MDLs (OM-27969)

    • Prevent duplicate custom expressions in exported MDLs by using a cache

    • Add support for radians and degrees in custom expressions in exported MDLs

    • Add support for mul in custom expressions in exported MDLs (OM-29276)

    • Support exporting additional outputs for custom expressions (OM-29276)

    • Support exporting additional outputs for custom expressions (OM-29276)

    • Support additional float4 constructors in custom expressions (OM-29276)

    • Unifying the material loading for USD skeletal and static meshes (OM-29351)

    • Add support for DistanceToNearestSurface material node when exporting MDLs by using a constant value to generate a valid material (OM-30208)

  • Skeletal Meshes

    • Reorganize the hierarchy of UsdSkelRoot to fix a missing UsdSkeleton transform, also helpful for the multiple skeletons. (OM-29351)

      • Old: UsdSkelRoot -> SkeletalMeshActor

      • New: UsdSkelRoot -> Actor and UsdSkeleton + UsdMesh -> SkeletalMeshActor

  • Landscapes

    • Export Landscape actors with a GeomSubset and MDL Preset for each Landscape component to address issues with the visibility mask (OM-29643)

    • Only export the Landscape visibility mask once, as opposed to once for every layer

  • Lights

    • Improve skylight when importing a USD stage (OM-27528)

    • Add support for importing USD DomeLights as UE4 sky sphere mesh plus a material that supports some DomeLight properties (textures, exposure, intensity, color)