• Fixed crash caused by previous backport of 5.4 fixes.
• Prevent potential loop if we loose the session while cooking/instanting.

Add preliminary support for LODGroup in KineFX FBX exporter. Houdini now creates an LODGroup FBX node for mesh parent or joint nodes that start with `LODGroup` instead of previously creating a Null or Limb FBX nodes. There's still no support for specifying the LOD properties like display factor, etc. though, left as future work.

Fixed an issue where the Maya 2025 engine directory was not installed correctly.

Fixed crashes that could occur during some operations on RHEL 9.4 and its derivatives.

Added support for Maya 2025.

Fixed a bug where animated subd tags were not being updated in IPR, or offline when rendering multiple frames within single process.

The TOP Fetch Input node, typicaly used in graphs fetched using the TOP Fetch, now has options to control its behavior when used outside of a typical fetch context. For example, if the node is cooked interactively instead.

Karma Render Properties LOP 3-400% performance improvements on large scenes.

Extract Instances LOP now handles array primvars with ElementSize metadata and has an option to flatten array primvars to scalar primvars.

Karma Render Settings, Karma Standard RenderVars and Karma Render Products LOPs can now specify custom parent prim locations for the render products and rendervars.

Fix recently introduced crash in the Loft Payload Info LOP.

The VEX methods for getting the transform of a prim no longer require that the prim be an Xformable. These methods will work on any prim type by assuming that the transform of any non-Xformable prim is the same as its closest Xformable ancestor.

Port of most of the latest plugin fixes from H20.0:

• Added support of UE5.4
• Fixed reimport failing for .bgeo.sc files.
• Fix missing lock/unlock icon in Float3 parameter
• Lexicographic sorting of TOP nodes and networks in PDG details UI
• Values for the "unreal_gc_collisions_implicit_type" now follow the sameorder as the corresponding menu entries in Unreal:0 = Box, 1 = Sphere, 2 = Capsule, 3 = Level Set, 4 = None, 5 = Convex
• Fixed an issue with Convex implicit collision type not behaving as theynormally should due to missing convex hull data.
• Improved details panel refresh logic
• We now maintain focus on parameter widgets after refresh of Details panel.
• Fixed Button Strip parameter implementation
• Add support for Horizontally Join to Next Parameter option to Details UI.
• Fixed Proxy Meshes not having gamma corrected CPVs.
• Make default label visibility true in parameter object.
• Added pop-out window editor for ramp parameters.
• Support button strips with single selection choice list type.
• Update Unreal ref string parameter UI to match UE5 object picker.
• Added a new log command: Houdini.DumpGenericAttributeThis can be used to list all properties/generic attributes for a given class,listing the expected unreal_uproperty_XXX attribute names and types, as wellas if the system supports it.usage: Houdini.DumpGenericAttribute StaticMesh
• Added support for Rotators and Vector_NetQuantize100 property types to thegeneric attribute system.
• Merged PR#292 on behalf of @JanLoehr :Setting the respective Nanite FallbackTarget for given Fallback Values.
• Merged PR#286 on behalf of @paula721:Support for setting the CenterAdjust property on a Spline Segment Mesh.
• Merged PR#228 on behalf of @SilverWinter0511Added buttons for selecting temporary cook folder and bake folder.
• Improved the logic used for finding uproperty attributes

Fixed a crash that could occur when opening the network editor list view for a VOP Network with a Parameter VOP set to "Export: Always".

Fixed an issue where nested prim patterns were not properly propagating time-varying status from child to parent.

Added a %foreach auto-collection that runs a sub-pattern for each prim that matches a primary pattern.

Fixed a potential crash in Edit Material Network LOP when loading shaders.

Fixed an issue with custom tags not working correctly with ROP Fetch TOP. Output files were always using the first tag in the custom tag list, instead of the tag that matches the corresponding output parameter.

Fixed a crash when the Layer Replace LOP tries to replace a sublayer on the stage root layer.

When a relationship from a USD API schema is added as a parameter to an Edit Properties LOP, setting the relationship now applies the API schema, as was already happening for attributes from API schemas.

Added environment variable (HOUDINI_NO_EXTERNAL_ICON_CACHE) that can be used to disable external icon caches to aid in debugging cache problems.

Fixed a bug where Du/Dv VEX calls may sometimes return garbage when the input parameter is a uniform value.

Fixed a crash that could occur while opening a hip file if a context option change callback changes another context option's value.

Fixed hanging in Houdini related to Python SOP nodes. For example, Houdini would hang when cooking Python SOP nodes from Houdini Engine Session Sync, or when a background thread tried to call into HOM while Houdini cooked Python SOP nodes.

The fix required restoring old behavior in Python SOP nodes that unfortunately reintroduces an old hang, one at least that is limited in scope. The old hang occurs when Python SOP nodes execute multi-threaded code that calls into the HOM `hou` package from separate threads. If you wish to run such code in Python SOPs, then you can set `HOUDINI_ALLOW_PYTHON_SOP_MULTITHREADING=1` in the environment with the caveat that you may encounter other hangs as detailed above (i.e. cooking Python SOP nodes from Session Sync).