`skel` kit

158 tools. Generated from the plugin source; do not edit by hand.

Guide

Everything about the skeletal side of assets: the skeleton itself (bone tree, virtual bones, skeleton sockets, animation slot groups, curve metadata, blend profiles, per-bone translation retargeting, notify names, compatible skeletons), the deeper parts of a skeletal mesh (LOD info, reduction and build settings, sections, morph targets, skin weight profiles, reference pose, bounds, Niagara sampling, ray tracing, mesh merge, FBX export, import settings), physics assets (bodies, shapes, constraints, profiles, collision pairs) and clothing.

Works on UE 4.27 through 5.8 (~150 tools on 5.8, ~145 on 4.27). The 5.x-only tools are the compatible-skeleton list, the skin weight profile removal and the default mesh deformer; they are hidden from tools/list on 4.27 and refused with E_NOT_SUPPORTED if called anyway. The skel.cloth_* tools require the ChaosCloth plugin and disappear when it is not enabled.

The kit is split over five classes that all expose the skel. namespace:

Class	Prefix	What
`UUeaKit_Skeleton`	`skel.`	bone tree queries, virtual bones, skeleton sockets, slot groups, curve metadata, blend profiles, retargeting modes, notify names, preview mesh, compatible skeletons, bone-tree merge/recreate
`UUeaKit_SkelMesh`	`skel.`	LOD info / reduction / build settings, sections, material slots, morph targets, skin weight profiles, reference pose, bounds, sampling, ray tracing, merge, export, import settings
`UUeaKit_SkelPhysics`	`skel.pa_`	bodies and shapes, constraints with limits and motors, constraint and physical-animation profiles, collision pairs, mirroring, auto-generation
`UUeaKit_SkelCloth`	`skel.cloth_`	clothing assets: create from a section, bind/unbind, configs, weight maps
`UUeaKit_SkelBatch`	`skel.`	folder-wide audits and bulk edits

This kit does not replace the basic mesh.sk_* tools (info, LOD screen size, materials, mesh-local sockets, bone list, morph target names, physics asset assignment). Those stay in the mesh kit; skel.* goes deeper and never duplicates a mesh.sk_* name.

Not here: animation assets (anim kit), placing skeletal meshes in a level (actor kit), skeletal mesh component settings (component kit), importing a new mesh from FBX (asset kit).

Start here

skel.get_skeleton {"skeleton":"/Game/Characters/SK_Hero_Skeleton"} — bone count, root, virtual bones, sockets, slot groups, curves, blend profiles, preview mesh, compatible skeletons, notify names, retarget sources.
skel.get_mesh {"mesh":"/Game/Characters/SK_Hero"} — LOD infos, sections per LOD, material slots, morph targets, skin weight profiles, cloth, physics assets, bounds, sampling, ray tracing and the source files.
skel.pa_get {"physicsAsset":"/Game/Characters/PA_Hero"} — bodies with their shapes and physics settings, constraints with limits and drives, profiles, disabled collision pairs, solver settings.
skel.audit_meshes {"folder":"/Game/Characters","requireLods":true,"requirePhysicsAsset":true} — the whole folder in one table.

Everything that changes an asset is transactional (edit.undo works) but nothing is written to disk until you call skel.save_mesh, skel.save_skeleton, skel.pa_save or asset.save_all.

No skeletal mesh of your own to try this on? skel.create_test_mesh {"folder":"/Game/Tmp", "name":"SK_Test"} duplicates the engine's SkeletalCube (bones Bone01, Bone02) and its skeleton into your folder; that is exactly what the self-test uses.

Recipes

Ragdoll from scratch

skel.pa_create        {"mesh":"/Game/Characters/SK_Hero","folder":"/Game/Characters",
                       "name":"PA_Hero","geomType":"sphyl","minBoneSize":8,"createConstraints":true}
skel.pa_list_bodies   {"physicsAsset":"/Game/Characters/PA_Hero"}
skel.pa_set_body_physics {"physicsAsset":"/Game/Characters/PA_Hero","bone":"pelvis",
                          "physicsType":"simulated","massScale":1.0}
skel.pa_set_constraint_limits {"physicsAsset":"/Game/Characters/PA_Hero","name":"spine_02",
                               "swing1Motion":"limited","swing1Limit":25,
                               "swing2Motion":"limited","swing2Limit":25,
                               "twistMotion":"limited","twistLimit":10}
skel.pa_disable_collision_below {"physicsAsset":"/Game/Characters/PA_Hero","bone":"spine_01"}
skel.pa_validate      {"physicsAsset":"/Game/Characters/PA_Hero"}

skel.pa_create needs the mesh to have skin weights on the bones you want bodies on; bones shorter than minBoneSize are skipped unless bodyForAll is true. Start with sphyl (capsules) — the convex types are much slower and only pay off for hands and props.

For a driven ragdoll, add a physical animation profile:

skel.pa_add_profile {"physicsAsset":"...","name":"Hit","kind":"physicalAnimation"}
skel.pa_set_physical_animation_profile {"physicsAsset":"...","profile":"Hit","bone":"spine_02",
                                        "orientationStrength":2000,"angularVelocityStrength":100,
                                        "isLocalSimulation":true}

Mirroring a half-built physics asset

Build the left side only, then:

skel.pa_mirror {"physicsAsset":"/Game/Characters/PA_Hero","fromSuffix":"_l","toSuffix":"_r"}

Every body whose bone ends with _l is copied onto the matching _r bone with its shapes mirrored across the YZ plane (X negated, yaw and roll flipped). Use skel.pa_copy_body for a single bone.

Retarget-ready skeleton

skel.apply_retarget_preset {"skeleton":"/Game/Characters/SK_Hero_Skeleton","preset":"humanoid"}
skel.add_virtual_bone      {"skeleton":"...","source":"hand_l","target":"foot_l"}
skel.add_compatible_skeleton {"skeleton":"...","other":"/Game/Mannequin/UE4_Mannequin_Skeleton"}

The humanoid preset puts the root and every IK/virtual bone on Animation, the pelvis on AnimationScaled and everything else on Skeleton, which is what a proportion-independent retarget needs. Pass pelvisBone when the pelvis is not called pelvis/hips/spine_01. skel.add_compatible_skeleton is UE 5 only and lets an animation authored on the other skeleton play directly on this one.

LOD chain and section cleanup

skel.generate_lods   {"mesh":"/Game/Characters/SK_Hero","count":4,
                      "percents":[0.5,0.25,0.1],"screenSizes":[0.5,0.25,0.1]}
skel.set_lod_info    {"mesh":"...","lod":3,"bonesToRemove":["index_03_l","index_03_r"],
                      "rebuild":true}
skel.list_sections   {"mesh":"...","lod":0}
skel.set_section     {"mesh":"...","lod":0,"section":2,"generateUpToLod":1}

skel.generate_lods needs a mesh reduction plugin (SkeletalReduction ships with the engine but has to be enabled); it fails with E_INTERNAL otherwise. generateUpToLod on a section makes that section disappear past the given LOD — the cheapest way to drop buckles and buttons at distance. skel.set_lod_reduction and skel.set_lod_build_settings tune the same LOD without rebuilding unless you pass rebuild: true.

Morph target management

skel.list_morph_targets  {"mesh":"/Game/Characters/SK_Hero"}
skel.rename_morph_target {"mesh":"...","name":"blendShape1","newName":"JawOpen"}
skel.copy_morph_targets  {"mesh":"/Game/Characters/SK_HeroLod","from":"/Game/Characters/SK_Hero"}
skel.remove_all_morph_targets {"mesh":"/Game/Characters/SK_HeroProxy"}

copy_morph_targets refuses meshes whose LOD 0 vertex counts differ: morph deltas are indexed by vertex, so the topology must match exactly.

Mesh merge for modular characters

skel.merge_meshes {"meshes":["/Game/Mod/SK_Torso","/Game/Mod/SK_Legs","/Game/Mod/SK_Head"],
                   "folder":"/Game/Mod","name":"SK_Merged","stripTopLods":0}

Every source must be bound to a compatible skeleton; the merged asset gets the first source's skeleton unless you pass skeleton. Merging is an editor-time bake — for runtime swapping use leader-pose components from the component kit instead.

Cloth

skel.cloth_create_from_section {"mesh":"...","lod":0,"section":3,"name":"Cloak",
                                "removeSection":false,"physicsAsset":"/Game/Characters/PA_Hero"}
skel.cloth_set_config {"mesh":"...","name":"Cloak",
                       "values":[{"key":"BendingStiffness","value":"0.7"}]}
skel.cloth_set_weight_map_value {"mesh":"...","name":"Cloak","lod":0,"map":0,"value":10.0}

skel.cloth_set_config writes by reflection, so it works with any simulator config the enabled cloth plugin exposes; call skel.cloth_get_config first to see the property names. Weight map target 0 is MaxDistance, 1 BackstopDistance, 2 BackstopRadius.

Folder-wide work

skel.audit_skeletons        {"folder":"/Game/Characters"}
skel.batch_set_physics_asset {"folder":"/Game/Crowd","physicsAsset":"/Game/Crowd/PA_Shared",
                              "onlyMissing":true}
skel.batch_retarget_modes   {"folder":"/Game/Characters","preset":"humanoid"}

skel.audit_skeletons scans the registry once and reports how many meshes and animations use each skeleton, so orphaned skeletons stand out immediately.

Gotchas

4.27 vs 5.x accessors. The kit hides every difference behind its own shim, but the tools that simply do not exist below UE 5 are hidden from tools/list: skel.list_compatible_skeletons, skel.add_compatible_skeleton, skel.remove_compatible_skeleton, skel.remove_skin_weight_profile (5.0+) and skel.set_default_mesh_deformer (5.1+).
Reduction needs a plugin. skel.generate_lods, skel.regenerate_lod, skel.remove_lod and skel.batch_regenerate_lods all go through the engine's skeletal reduction path. Without a mesh reduction plugin they fail instead of silently doing nothing.
Rebuild costs. set_lod_info, set_lod_reduction, set_lod_build_settings and set_ref_pose_bone take rebuild; leave it false while you make several changes, then call skel.rebuild_mesh once. Rebuilding a character mesh takes seconds, not milliseconds.
Reference pose edits are dangerous. skel.set_ref_pose_bone changes the bind pose, which breaks existing animations and invalidates the physics asset. Regenerate the physics asset with skel.pa_regenerate afterwards, and use skel.reset_ref_pose to go back to the skeleton's pose.
Virtual bone names. The engine names virtual bones VB <source>_<target>. add_virtual_bone returns the actual name in createdName; rename_virtual_bone and remove_virtual_bones accept the name with or without the VB prefix (it is added for you).
Curve metadata moved. UE 5.7 removed smart names; the kit uses the new FCurveMetaData API there and the smart-name container below it. The tool shapes are identical, but skel.rename_curve fails on a name that is already taken on both paths.
Cloth plugin. Every skel.cloth_* tool declares RequiresPlugin="ChaosCloth". The plugin is off by default; enable it in the project before the tools become callable. The kit never links against the plugin, so its module rename between 4.27 (Chaos) and 5.x (ChaosCloth) does not matter.
Material slot removal. skel.remove_material_slot refuses a slot a section still uses; point the sections elsewhere with skel.set_section first. Removing a slot shifts every higher section material index down by one, which the tool does for you.
Physics asset deletion. skel.pa_delete fails while a mesh still references the asset; clear it with skel.set_physics_assets {"mesh":"...","physicsAsset":""} first.

Tools

Legend. risk 0 = read-only, 1 = harmless editor op, 2 = modifies asset, 3 = deletes/replaces asset, 4 = project/config/build op, 5 = potentially destructive (calls above MaxAutoRisk need "_confirm": true). mutates = runs in a transaction (edit.undo reverts). requires PIE / requires world = refused without a PIE session / an open level. requires plugin = unavailable while the plugin is disabled. dryRun = honours the dryRun argument. smoke = covered by edit.self_test.

`skel.add_compatible_skeleton` (risk 2, mutates, UE 5.0+, smoke)

Declares another skeleton compatible with this one (UE 5 only).

Argument	Type	Description
`other`	string	required. The other skeleton asset path or unique name.

Returns: skeleton, names, count, message, notes.

`skel.add_curve` (risk 2, mutates, smoke)

Registers a curve name on the skeleton (metadata only; it does not create animation data).

Argument	Type	Description
`name`	string	required. Curve name.
`morphTarget`	boolean	Mark the curve as driving a morph target. Default `false`.
`material`	boolean	Mark the curve as driving a material parameter. Default `false`.
`maxLod`	integer	Lowest-detail LOD the curve is still evaluated on; -1 leaves it unchanged, 255 = always. Default `-1`.
`linkedBones`	array of string	Bones the curve is linked to (skel.set_curve_metadata only; empty leaves them unchanged).

Returns: skeleton, curves, count, message, notes.

`skel.add_material_slot` (risk 2, mutates, smoke)

Adds a material slot to a skeletal mesh.

Argument	Type	Description
`material`	string	Material asset path; the slot stays empty when omitted.
`slotName`	string	Slot name; generated when omitted.

Returns: mesh, materials, count, message, notes.

`skel.add_notify_name` (risk 2, mutates, smoke)

Adds a notify name to the skeleton's cached list (so it shows up in the notify pickers).

Argument	Type	Description
`name`	string	required. Name to operate on.

Returns: skeleton, names, count, message, notes.

`skel.add_skeleton_socket` (risk 2, mutates, smoke)

Adds a socket attached to a bone of the skeleton.

Argument	Type	Description
`name`	string	required. Socket name.
`bone`	string	Bone the socket is attached to (required when adding).
`location`	{x,y,z}	Offset from the bone.
`rotation`	{x,y,z}	Rotation as pitch/yaw/roll.
`scale`	{x,y,z}	Scale; (0,0,0) means 1,1,1.
`forceAlwaysAnimated`	boolean	Keep the socket's bone animated even when it is not otherwise required. Default `false`.
`newName`	string	New socket name (skel.set_skeleton_socket only).

Returns: skeleton, sockets, count, message, notes.

`skel.add_slot` (risk 2, mutates, smoke)

Adds an animation slot to a group (DefaultGroup when 'group' is empty).

Argument	Type	Description
`slot`	string	Slot name (skel.add_slot, skel.set_slot_group, skel.remove_slot).
`group`	string	Slot group name (defaults to DefaultGroup for skel.add_slot).

Returns: skeleton, groups, count, message, notes.

`skel.add_slot_group` (risk 2, mutates, smoke)

Adds a slot group.

Argument	Type	Description
`slot`	string	Slot name (skel.add_slot, skel.set_slot_group, skel.remove_slot).
`group`	string	Slot group name (defaults to DefaultGroup for skel.add_slot).

Returns: skeleton, groups, count, message, notes.

`skel.add_virtual_bone` (risk 2, mutates, smoke)

Adds a virtual bone parented to 'source' and following 'target'; returns the generated name.

Argument	Type	Description
`source`	string	required. Bone the virtual bone is parented to.
`target`	string	required. Bone the virtual bone follows.
`name`	string	Explicit virtual bone name (UE 5 only; the engine generates one when empty).

Returns: skeleton, virtualBones, count, createdName, message, notes.

`skel.apply_retarget_preset` (risk 2, mutates, smoke)

Applies a retargeting preset to the whole bone tree ('humanoid' keeps the root and the IK bones on Animation and scales the pelvis).

Argument	Type	Description
`preset`	string	required. humanoid (root=Animation, pelvis=AnimationScaled, IK bones=Animation, rest=Skeleton) or animation / skeleton (everything).
`pelvisBone`	string	Name of the pelvis/hips bone; auto-detected when empty.

Returns: skeleton, modes, count, changed, message, notes.

`skel.audit_meshes` (risk 0, smoke)

Audits the skeletal meshes of a folder: triangle budget, LOD count, physics asset, morph targets.

Argument	Type	Description
`folder`	string	required. Content folder to audit.
`maxTriangles`	integer	Flag meshes whose LOD 0 has more triangles than this; 0 disables the check. Default `0`.
`requireLods`	boolean	Flag meshes with a single LOD. Default `false`.
`requirePhysicsAsset`	boolean	Flag meshes without a physics asset. Default `false`.
`requireMorphs`	boolean	Flag meshes without morph targets. Default `false`.
`offendersOnly`	boolean	Only report the meshes that failed a check. Default `false`.
`limit`	integer	Maximum number of meshes inspected. Default `200`.

Returns: folder, meshes, count, offenders, totalTriangles, message.

`skel.audit_physics_assets` (risk 0, smoke)

Audits the physics assets of a folder: bodies without shapes, constraints, disabled collision pairs.

Argument	Type	Description
`folder`	string	required. Content folder to audit.
`limit`	integer	Maximum number of assets inspected. Default `200`.

Returns: folder, physicsAssets, count, offenders, message.

`skel.audit_skeletons` (risk 0, smoke)

Audits the skeletons of a folder: bones, virtual bones, sockets, and how many meshes and animations use each one.

Argument	Type	Description
`folder`	string	required. Content folder to audit.
`limit`	integer	Maximum number of assets inspected. Default `200`.

Returns: folder, skeletons, count, orphaned, message.

`skel.batch_regenerate_lods` (risk 3, mutates, destructive)

Regenerates the LOD chain of every skeletal mesh of a folder. Not smoke-tested: skeletal reduction needs a mesh reduction plugin.

Argument	Type	Description
`count`	integer	Total number of LODs including LOD0. Default `3`.

Returns: folder, changed, skipped, count, message.

`skel.batch_retarget_modes` (risk 3, mutates, smoke)

Applies a retargeting preset to every skeleton of a folder.

Argument	Type	Description
`preset`	string	required. humanoid, animation or skeleton.

Returns: folder, changed, skipped, count, message.

`skel.batch_set_lod_settings` (risk 3, mutates, smoke)

Assigns one SkeletalMeshLODSettings asset to every skeletal mesh of a folder.

Argument	Type	Description
`settings`	string	required. SkeletalMeshLODSettings asset path.
`apply`	boolean	Immediately copy the settings into the LOD infos. Default `true`.

Returns: folder, changed, skipped, count, message.

`skel.batch_set_physics_asset` (risk 3, mutates, smoke)

Assigns one physics asset to every skeletal mesh of a folder (optionally only to those without one).

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path.
`onlyMissing`	boolean	Only touch the meshes that have no physics asset yet. Default `false`.

Returns: folder, changed, skipped, count, message.

`skel.batch_set_skeleton` (risk 3, mutates, destructive, smoke)

Rebinds every skeletal mesh of a folder to one skeleton (refused when the hierarchies differ unless 'force').

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path.
`force`	boolean	Rebind even when the bone hierarchies do not match. Default `false`.

Returns: folder, changed, skipped, count, message.

`skel.cloth_bind` (risk 2, mutates, requires plugin ChaosCloth)

Binds an existing clothing asset to a mesh section. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`name`	string	required. Clothing asset name.
`lod`	integer	required. LOD of the section to drive.
`section`	integer	required. Section to drive.
`clothLod`	integer	Cloth LOD used for the binding. Default `0`.

Returns: mesh, lod, section, clothingAsset, clothLod, bound, message.

`skel.cloth_create_from_section` (risk 3, mutates, requires plugin ChaosCloth)

Creates a clothing asset from a mesh section and binds it to that section. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`lod`	integer	required. LOD the source section lives in.
`section`	integer	required. Section index to turn into cloth.
`name`	string	required. Name of the new clothing asset.
`removeSection`	boolean	Leave the source section out of the rendered mesh. Default `false`.
`physicsAsset`	string	Physics asset the cloth collisions are taken from.

Returns: mesh, clothingAssets, count, message, notes.

`skel.cloth_get` (risk 0, requires plugin ChaosCloth)

One clothing asset in detail. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`name`	string	required. Clothing asset name (or index as text).

Returns: mesh, clothingAssets, count, message, notes.

`skel.cloth_get_config` (risk 0, requires plugin ChaosCloth)

Every property of a cloth simulator config, read by reflection. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`name`	string	required. Clothing asset name.
`config`	string	Config object name (ChaosClothConfig by default).
`values`	array of UeaKeyValue	Properties to set, as "PropertyName=Value" pairs (skel.cloth_set_config only).

Returns: mesh, clothingAsset, config, values, failed, message.

`skel.cloth_get_section_binding` (risk 0, requires plugin ChaosCloth)

Which clothing asset (if any) drives a mesh section. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`lod`	integer	required. LOD index.
`section`	integer	required. Section index.

Returns: mesh, lod, section, clothingAsset, clothLod, bound, message.

`skel.cloth_list` (risk 0, requires plugin ChaosCloth)

Clothing assets bound to a skeletal mesh, with their LOD count, reference bone and configs. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, clothingAssets, count, message, notes.

`skel.cloth_list_weight_maps` (risk 0, requires plugin ChaosCloth)

Weight maps (max distance, backstop, ...) of a cloth LOD with their value ranges. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`name`	string	required. Clothing asset name.
`lod`	integer	Cloth LOD index; -1 lists every LOD. Default `-1`.

Returns: mesh, clothingAsset, weightMaps, count, message.

`skel.cloth_rebuild` (risk 2, mutates, requires plugin ChaosCloth)

Rebuilds the cached simulation data of a clothing asset after a config or weight map change. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`name`	string	required. Clothing asset name (or index as text).

Returns: mesh, clothingAssets, count, message, notes.

`skel.cloth_remove` (risk 3, mutates, destructive, requires plugin ChaosCloth)

Removes a clothing asset from the mesh (and unbinds every section it drove). Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`name`	string	required. Clothing asset name (or index as text).

Returns: mesh, clothingAssets, count, message, notes.

`skel.cloth_set_config` (risk 2, mutates, requires plugin ChaosCloth)

Writes properties of a cloth simulator config by name (reflection, so it works with any simulator). Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`name`	string	required. Clothing asset name.
`config`	string	Config object name (ChaosClothConfig by default).
`values`	array of UeaKeyValue	Properties to set, as "PropertyName=Value" pairs (skel.cloth_set_config only).

Returns: mesh, clothingAsset, config, values, failed, message.

`skel.cloth_set_weight_map_value` (risk 3, mutates, requires plugin ChaosCloth)

Fills a whole weight map of a cloth LOD with one value. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`name`	string	required. Clothing asset name.
`lod`	integer	required. Cloth LOD index.
`map`	integer	required. Weight map target (numeric id, e.g. 0 = MaxDistance).
`value`	number	required. Value written into every vertex of the map.

Returns: mesh, clothingAsset, weightMaps, count, message.

`skel.cloth_unbind` (risk 2, mutates, requires plugin ChaosCloth)

Removes the cloth simulation from a mesh section. Not smoke-tested: needs the ChaosCloth plugin.

Argument	Type	Description
`lod`	integer	required. LOD index.
`section`	integer	required. Section index.

Returns: mesh, lod, section, clothingAsset, clothLod, bound, message.

`skel.copy_lod_settings` (risk 2, mutates, smoke)

Copies every LOD info (screen sizes, reduction, bake poses) from another skeletal mesh.

Argument	Type	Description
`from`	string	required. Source skeletal mesh asset path or unique name.

Returns: mesh, lods, count, message, notes.

`skel.copy_morph_targets` (risk 2, mutates, smoke)

Copies the morph targets of another mesh (both meshes must have the same vertex count).

Argument	Type	Description
`from`	string	required. Source skeletal mesh asset path or unique name.

Returns: mesh, morphTargets, count, message, notes.

`skel.create_blend_profile` (risk 2, mutates, smoke)

Creates a blend profile (mode TimeFactor / WeightFactor / BlendMask; UE 4.27 has no modes).

Argument	Type	Description
`name`	string	required. Blend profile name.
`mode`	string	TimeFactor (default), WeightFactor or BlendMask. Ignored on UE 4.27, which has no modes.

Returns: skeleton, profiles, count, message, notes.

`skel.create_test_mesh` (risk 2, mutates, smoke)

Duplicates the engine's SkeletalCube (and its skeleton) into a folder; the fixture every other skel tool can be tried on.

Argument	Type	Description
`folder`	string	required. Destination content folder.
`name`	string	required. Name of the new skeletal mesh (its skeleton gets "_Skeleton" appended).

Returns: mesh, name, folder, skeleton, bones, message, notes.

`skel.duplicate_mesh` (risk 2, mutates, smoke)

Duplicates a skeletal mesh into another folder or under another name.

Argument	Type	Description
`folder`	string	Destination content folder; the source folder when empty.
`name`	string	required. Name of the copy.

Returns: mesh, name, folder, skeleton, bones, message, notes.

`skel.export_fbx` (risk 1)

Exports a skeletal mesh to an FBX file. Not smoke-tested: it writes outside the content folder.

Argument	Type	Description
`file`	string	required. Destination file path (absolute, or relative to the project directory).
`ascii`	boolean	Write ASCII FBX instead of binary. Default `false`.
`exportMorphTargets`	boolean	Include morph targets in the export. Default `true`.
`lod`	integer	LOD to export; negative exports the whole chain. Default `-1`.

Returns: mesh, message, lods, notes.

`skel.find_bones` (risk 0, smoke)

Finds bones by wildcard pattern ("hand_", "_l"); a plain word matches as a substring.

Argument	Type	Description
`pattern`	string	required. Wildcard pattern ("hand_", "_l"); a plain word matches as a substring.
`limit`	integer	Maximum number of bones returned. Default `200`.

Returns: skeleton, bones, count, total, message.

`skel.generate_lods` (risk 3, mutates)

Builds a whole LOD chain by reduction. Not smoke-tested: skeletal reduction needs a mesh reduction plugin the smoke project does not enable.

Argument	Type	Description
`count`	integer	required. Total number of LODs including LOD0.
`percents`	array of number	Triangle fraction per generated LOD (default 0.5, 0.25, 0.125...).
`screenSizes`	array of number	Screen size per generated LOD.

Returns: mesh, lods, count, message, notes.

`skel.get_bone` (risk 0, smoke)

One bone in detail: local and component-space reference transform, children and retargeting mode.

Argument	Type	Description
`bone`	string	required. Bone name (case-insensitive).

Returns: skeleton, bone, componentLocation, componentRotation, componentScale, children, message.

`skel.get_bone_chain` (risk 0, smoke)

Bone path between two bones (walks up from 'to' until it reaches 'from').

Argument	Type	Description
`from`	string	required. First bone of the chain.
`to`	string	required. Last bone of the chain.

Returns: skeleton, bones, count, message.

`skel.get_bone_influences` (risk 0, smoke)

How many vertices of a LOD a bone influences, and the strongest weight found.

Argument	Type	Description
`bone`	string	required. Bone name.
`lod`	integer	LOD index (0 when omitted). Default `0`.

Returns: mesh, bone, lod, influencedVertices, maxWeight, sections, message.

`skel.get_import_settings` (risk 0, smoke)

FBX import settings stored on the mesh (they apply to the next reimport).

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, importDataClass, settings, sourceFiles, canReimport, message, notes.

`skel.get_lod_build_settings` (risk 0, smoke)

Build settings of one LOD (normals, tangents, MikkTSpace, welding thresholds).

Argument	Type	Description
`lod`	integer	required. LOD index (0-based).

Returns: mesh, importDataClass, settings, sourceFiles, canReimport, message, notes.

`skel.get_lod_info` (risk 0, smoke)

LOD info of one LOD (-1 returns every LOD): screen size, hysteresis, reduction, bake pose, bones to remove.

Argument	Type	Description
`lod`	integer	LOD index (0-based); -1 means every LOD. Default `-1`.

Returns: mesh, lods, count, message, notes.

`skel.get_mesh` (risk 0, smoke)

Deep information about a skeletal mesh: LOD infos, sections, materials, morph targets, skin weight profiles, cloth, physics, bounds, sampling, ray tracing and import settings.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, name, skeleton, boneCount, lods, sections, materials, morphTargets, skinWeightProfiles, clothingAssets, physicsAsset, shadowPhysicsAsset, lodSettings, postProcessAnimBlueprint, defaultMeshDeformer, minLod, boundsOrigin, boundsExtent, positiveBoundsExtension, negativeBoundsExtension, samplingRegions, supportRayTracing, rayTracingMinLod, sourceFiles, message.

`skel.get_ref_pose` (risk 0, smoke)

Reference pose of a skeletal mesh, in local (default) or component space.

Argument	Type	Description
`bones`	array of string	Bones to report; empty reports every bone.
`space`	string	local (relative to the parent, default) or component.
`limit`	integer	Maximum number of bones returned. Default `300`.

Returns: mesh, space, bones, count, message, notes.

`skel.get_required_bones` (risk 0, smoke)

Bones required to render a LOD, and the bones that actually have weights on it.

Argument	Type	Description
`lod`	integer	required. LOD index (0-based).

Returns: mesh, lod, requiredBones, activeBones, count, message.

`skel.get_retarget_modes` (risk 0, smoke)

Translation retargeting mode of every bone of the skeleton.

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, modes, count, changed, message, notes.

`skel.get_skeleton` (risk 0, smoke)

Everything about a skeleton: bone count, root, virtual bones, sockets, slot groups, curves, blend profiles, preview mesh, compatible skeletons, notify names and retarget sources.

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, name, boneCount, rootBone, virtualBones, sockets, slotGroups, curves, blendProfiles, previewMesh, compatibleSkeletons, notifyNames, retargetSources, message.

`skel.get_vertex_info` (risk 0, smoke)

Position, normal, first UV and bone weights of one vertex of a LOD.

Argument	Type	Description
`vertex`	integer	required. Vertex index inside the LOD.
`lod`	integer	LOD index (0 when omitted). Default `0`.

Returns: mesh, lod, vertex, position, normal, uv, influences, message.

`skel.import_lod` (risk 3, mutates)

Imports (or reimports) a LOD from an FBX file. Not smoke-tested: it needs an FBX file on disk.

Argument	Type	Description
`lod`	integer	required. LOD index to import into.
`file`	string	required. Absolute path of the FBX file.

Returns: mesh, lods, count, message, notes.

`skel.is_mesh_compatible` (risk 0, smoke)

Whether a skeletal mesh's bone hierarchy matches this skeleton.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: skeleton, other, compatible, message.

`skel.list_animations_using_skeleton` (risk 0, smoke)

Animation assets bound to a skeleton (asset registry query, nothing is loaded).

Argument	Type	Description
`classFilter`	string	Keep only assets of this class (AnimSequence, AnimMontage, BlendSpace...); empty = every animation asset.
`limit`	integer	Maximum number of assets returned. Default `200`.

Returns: skeleton, assets, count, message, notes.

`skel.list_blend_profiles` (risk 0, smoke)

Blend profiles of a skeleton with their mode and per-bone scales.

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, profiles, count, message, notes.

`skel.list_bones` (risk 0, smoke)

Bones of a skeleton with index, parent, depth, reference-pose local transform and retargeting mode.

Argument	Type	Description
`parent`	string	Only list this bone and its descendants.
`depth`	integer	Maximum hierarchy depth returned relative to the root (-1 = no limit). Default `-1`.
`nameContains`	string	Keep only bones whose name contains this text.
`limit`	integer	Maximum number of bones returned. Default `300`.

Returns: skeleton, bones, count, total, message.

`skel.list_compatible_skeletons` (risk 0, UE 5.0+, smoke)

Skeletons declared compatible with this one (UE 5 only; animations of a compatible skeleton can be played directly).

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, names, count, message, notes.

`skel.list_curves` (risk 0, smoke)

Curve metadata of a skeleton: name, morph target / material flags, max LOD and linked bones.

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, curves, count, message, notes.

`skel.list_material_slots` (risk 0, smoke)

Material slots of a skeletal mesh, with the slot names and whether a section uses them.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, materials, count, message, notes.

`skel.list_meshes_using_skeleton` (risk 0, smoke)

Skeletal meshes bound to a skeleton (asset registry query, nothing is loaded).

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, assets, count, message, notes.

`skel.list_morph_targets` (risk 0, smoke)

Morph targets of a skeletal mesh with the number of vertex deltas per LOD.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, morphTargets, count, message, notes.

`skel.list_notify_names` (risk 0, smoke)

Animation notify names cached on the skeleton.

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, names, count, message, notes.

`skel.list_sections` (risk 0, smoke)

Sections of a LOD (-1 = every LOD) with material slot, counts and per-section flags.

Argument	Type	Description
`lod`	integer	LOD index (0-based); -1 means every LOD. Default `-1`.

Returns: mesh, sections, count, message, notes.

`skel.list_skeleton_sockets` (risk 0, smoke)

Sockets stored on the skeleton (shared by every mesh bound to it).

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, sockets, count, message, notes.

`skel.list_skeletons` (risk 0, smoke)

Lists skeleton assets under a content folder.

Argument	Type	Description
`folder`	string	Content folder to search ("/Game" when empty).
`nameContains`	string	Keep only skeletons whose name contains this text.
`limit`	integer	Maximum number of skeletons returned. Default `100`.

Returns: skeletons, count, message.

`skel.list_skin_weight_profiles` (risk 0, smoke)

Skin weight profiles of a skeletal mesh.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, profiles, count, message, notes.

`skel.list_slot_groups` (risk 0, smoke)

Animation slot groups of a skeleton and the slots they contain.

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, groups, count, message, notes.

`skel.list_virtual_bones` (risk 0, smoke)

Virtual bones of a skeleton (derived bones between a source and a target bone).

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, virtualBones, count, createdName, message, notes.

`skel.merge_bones_from_mesh` (risk 2, mutates, smoke)

Adds the bones of a mesh that the skeleton does not know yet to its bone tree.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: skeleton, message, notes.

`skel.merge_meshes` (risk 2, mutates, smoke)

Merges several skeletal meshes into a new asset (modular characters).

Argument	Type	Description
`meshes`	array of string	required. Source skeletal meshes, in draw order.
`folder`	string	required. Destination content folder.
`name`	string	required. Name of the merged asset.
`skeleton`	string	Skeleton for the merged mesh; the first source mesh's skeleton when empty.
`stripTopLods`	integer	Number of top LODs to strip from the sources. Default `0`.

Returns: mesh, name, folder, skeleton, bones, message, notes.

`skel.pa_add_body` (risk 2, mutates, smoke)

Adds a physics body on a bone with one default shape.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.
`shape`	string	capsule (default), box or sphere.
`size`	number	Shape size: radius for sphere/capsule, half-extent for box. Default `5.0`.
`physicsType`	string	default, kinematic or simulated.

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_add_constraint` (risk 2, mutates, smoke)

Creates a constraint between two bones (preset locked, free or ragdoll).

Argument	Type	Description
`bone1`	string	required. Child bone.
`bone2`	string	required. Parent bone.
`name`	string	Joint name; the child bone name when empty.
`preset`	string	locked, free or ragdoll (limited swings and twist).

Returns: physicsAsset, constraints, count, message, notes.

`skel.pa_add_profile` (risk 2, mutates, smoke)

Adds a constraint or physical animation profile.

Argument	Type	Description
`name`	string	required. Profile name.
`kind`	string	required. constraint or physicalAnimation.
`newName`	string	New name (skel.pa_rename_profile only).

Returns: physicsAsset, constraintProfiles, physicalAnimationProfiles, message, notes.

`skel.pa_add_shape` (risk 2, mutates, smoke)

Adds a collision shape to a body.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.
`type`	string	required. box, sphere or capsule.
`index`	integer	Shape index inside its type list (skel.pa_set_shape / skel.pa_remove_shape). Default `0`.
`center`	{x,y,z}	Shape centre relative to the bone.
`rotation`	{x,y,z}	Shape rotation as pitch/yaw/roll.
`extent`	{x,y,z}	Full extents of a box shape; (0,0,0) leaves them unchanged.
`radius`	number	Radius of a sphere or capsule; negative leaves it unchanged. Default `-1.0`.
`length`	number	Length of a capsule's line segment; negative leaves it unchanged. Default `-1.0`.
`name`	string	Optional shape name.
`contributeToMass`	boolean	Whether the shape adds to the body's mass. Default `true`.

Returns: physicsAsset, bone, shapes, count, message, notes.

`skel.pa_assign_to_mesh` (risk 2, mutates, smoke)

Assigns the physics asset to a skeletal mesh (as the main or the shadow physics asset).

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.
`shadow`	boolean	Assign it as the shadow physics asset instead of the main one. Default `false`.

Returns: physicsAsset, message, notes.

`skel.pa_copy_body` (risk 2, mutates, smoke)

Copies the shapes and settings of one body onto another bone, optionally mirrored.

Argument	Type	Description
`from`	string	required. Source bone.
`to`	string	required. Destination bone (its body is created when missing).
`mirror`	boolean	Mirror the shapes across the YZ plane (X is negated). Default `false`.

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_create` (risk 3, mutates, smoke)

Creates a physics asset from a skeletal mesh's bones (geometry type, minimum bone size, constraints) and optionally assigns it.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh the bodies are generated from.
`folder`	string	Destination content folder (skel.pa_create only).
`name`	string	Name of the new physics asset (skel.pa_create only).
`minBoneSize`	number	Bones shorter than this are skipped. Default `20.0`.
`geomType`	string	sphyl (capsule, default), box, sphere, singleConvex, multiConvex or taperedCapsule.
`vertWeight`	string	anyWeight or dominantWeight (default).
`autoOrient`	boolean	Orient the created bodies along their bone. Default `true`.
`createConstraints`	boolean	Create constraints between adjacent bodies. Default `true`.
`walkPastSmall`	boolean	Keep walking past bones that are too small instead of stopping. Default `true`.
`bodyForAll`	boolean	Create a body for every bone, even the small ones. Default `false`.
`disableCollisionsByDefault`	boolean	Disable collision between the created bodies by default. Default `true`.
`hullCount`	integer	Number of hulls for the convex geometry types. Default `4`.
`maxHullVerts`	integer	Maximum vertices per convex hull. Default `16`.
`assign`	boolean	Also assign the asset to the mesh (skel.pa_create only). Default `true`.

Returns: physicsAsset, name, folder, bodies, constraints, boneNames, message, notes.

`skel.pa_delete` (risk 3, mutates, destructive)

Deletes the physics asset. Not smoke-tested: deleting an asset inside the self-test transaction is unsafe.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path or unique name.

Returns: physicsAsset, message, notes.

`skel.pa_disable_collision_below` (risk 2, mutates, smoke)

Disables collision between a bone's body and every body below it in the hierarchy.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.

Returns: physicsAsset, pairs, count, message, notes.

`skel.pa_enable_all_collision` (risk 3, mutates, smoke)

Clears the whole collision-disable table, so every body collides with every other one.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path or unique name.

Returns: physicsAsset, pairs, count, message, notes.

`skel.pa_get` (risk 0, smoke)

Everything about a physics asset: bodies, shapes, constraints, profiles, disabled collision pairs and solver settings.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path or unique name.

Returns: physicsAsset, name, previewMesh, bodies, constraints, constraintProfiles, physicalAnimationProfiles, disabledCollisionPairs, solverSettings, message, notes.

`skel.pa_get_body` (risk 0, smoke)

One body in detail.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_get_constraint` (risk 0, smoke)

One constraint in detail (by joint name or index).

Argument	Type	Description
`name`	string	required. Joint name (or index as text).

Returns: physicsAsset, constraints, count, message, notes.

`skel.pa_list` (risk 0, smoke)

Lists physics assets under a content folder.

Argument	Type	Description
`folder`	string	Content folder to search ("/Game" when empty).
`limit`	integer	Maximum number of assets returned. Default `100`.

Returns: physicsAssets, count, message, notes.

`skel.pa_list_bodies` (risk 0, smoke)

Bodies of a physics asset with their shapes and physics settings.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path or unique name.

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_list_collision_pairs` (risk 0, smoke)

Body pairs whose collision is disabled (or every pair).

Argument	Type	Description
`disabledOnly`	boolean	Only report the pairs whose collision is disabled. Default `true`.

Returns: physicsAsset, pairs, count, message, notes.

`skel.pa_list_constraints` (risk 0, smoke)

Constraints of a physics asset with their limits and drives.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path or unique name.

Returns: physicsAsset, constraints, count, message, notes.

`skel.pa_list_profiles` (risk 0, smoke)

Constraint and physical animation profile names.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path or unique name.

Returns: physicsAsset, constraintProfiles, physicalAnimationProfiles, message, notes.

`skel.pa_list_shapes` (risk 0, smoke)

Collision shapes of one body.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.

Returns: physicsAsset, bone, shapes, count, message, notes.

`skel.pa_mirror` (risk 2, mutates, smoke)

Mirrors every body whose bone ends with one suffix onto the bone with the other suffix.

Argument	Type	Description
`fromSuffix`	string	required. Suffix of the source bones (e.g. "_l").
`toSuffix`	string	required. Suffix of the destination bones (e.g. "_r").

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_regenerate` (risk 3, mutates, destructive, smoke)

Regenerates the bodies and constraints of an existing physics asset from a mesh.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset to regenerate.

Returns: physicsAsset, name, folder, bodies, constraints, boneNames, message, notes.

`skel.pa_remove_body` (risk 3, mutates, destructive, smoke)

Removes the physics body of a bone (and the constraints that used it).

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_remove_constraint` (risk 3, mutates, destructive, smoke)

Removes a constraint.

Argument	Type	Description
`name`	string	required. Joint name (or index as text).

Returns: physicsAsset, constraints, count, message, notes.

`skel.pa_remove_profile` (risk 3, mutates, destructive, smoke)

Removes a constraint or physical animation profile.

Argument	Type	Description
`name`	string	required. Profile name.
`kind`	string	required. constraint or physicalAnimation.
`newName`	string	New name (skel.pa_rename_profile only).

Returns: physicsAsset, constraintProfiles, physicalAnimationProfiles, message, notes.

`skel.pa_remove_shape` (risk 3, mutates, destructive, smoke)

Removes a collision shape from a body.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.
`type`	string	required. box, sphere or capsule.
`index`	integer	Shape index inside its type list (skel.pa_set_shape / skel.pa_remove_shape). Default `0`.
`center`	{x,y,z}	Shape centre relative to the bone.
`rotation`	{x,y,z}	Shape rotation as pitch/yaw/roll.
`extent`	{x,y,z}	Full extents of a box shape; (0,0,0) leaves them unchanged.
`radius`	number	Radius of a sphere or capsule; negative leaves it unchanged. Default `-1.0`.
`length`	number	Length of a capsule's line segment; negative leaves it unchanged. Default `-1.0`.
`name`	string	Optional shape name.
`contributeToMass`	boolean	Whether the shape adds to the body's mass. Default `true`.

Returns: physicsAsset, bone, shapes, count, message, notes.

`skel.pa_rename_profile` (risk 2, mutates, smoke)

Renames a constraint or physical animation profile.

Argument	Type	Description
`name`	string	required. Profile name.
`kind`	string	required. constraint or physicalAnimation.
`newName`	string	New name (skel.pa_rename_profile only).

Returns: physicsAsset, constraintProfiles, physicalAnimationProfiles, message, notes.

`skel.pa_save` (risk 1)

Saves the physics asset package to disk. Not smoke-tested: the self-test never writes to disk.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path or unique name.

Returns: physicsAsset, message, notes.

`skel.pa_scale_shapes` (risk 2, mutates, smoke)

Scales every collision shape of the asset (or of some bones) by a factor.

Argument	Type	Description
`factor`	number	required. Scale factor applied to every radius/extent.
`bones`	array of string	Bones to scale; empty scales every body.

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_set_body_collision` (risk 2, mutates, smoke)

Collision settings of one body: collision enabled mode, object type and per-channel responses.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.
`collisionEnabled`	string	noCollision, queryOnly, physicsOnly or queryAndPhysics ("" leaves it unchanged).
`objectType`	string	Collision object type channel name (WorldStatic, Pawn, PhysicsBody...).
`responses`	array of UeaKeyValue	Per-channel responses as "Channel=ignore

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_set_body_physics` (risk 2, mutates, smoke)

Physics settings of one body: simulation type, mass, damping, gravity, CCD, centre of mass, physical material.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.
`physicsType`	string	default, kinematic or simulated ("" leaves it unchanged).
`massScale`	number	Multiplier applied to the computed mass; negative leaves it unchanged. Default `-1.0`.
`massKg`	number	Explicit mass in kilograms; negative leaves the computed mass. Default `-1.0`.
`linearDamping`	number	Linear damping; negative leaves it unchanged. Default `-1.0`.
`angularDamping`	number	Angular damping; negative leaves it unchanged. Default `-1.0`.
`enableGravity`	boolean	Whether gravity acts on the body. Default `true`.
`simulatePhysics`	boolean	Whether the body simulates by default. Default `false`.
`startAwake`	boolean	Whether the body starts awake. Default `true`.
`useCCD`	boolean	Use continuous collision detection. Default `false`.
`centerOfMassOffset`	{x,y,z}	Offset applied to the centre of mass.
`physicalMaterial`	string	Physical material asset path ("" leaves it unchanged).

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_set_collision_pair` (risk 2, mutates, smoke)

Enables or disables collision between the bodies of two bones.

Argument	Type	Description
`bone1`	string	required. First bone.
`bone2`	string	required. Second bone.
`enabled`	boolean	True to let the two bodies collide. Default `true`.

Returns: physicsAsset, pairs, count, message, notes.

`skel.pa_set_constraint` (risk 2, mutates, smoke)

General constraint settings: collision, projection, break thresholds, parent dominance, frame rotation.

Argument	Type	Description
`name`	string	required. Joint name.
`disableCollision`	boolean	Make the two bodies ignore each other. Default `true`.
`projectionEnabled`	boolean	Enable joint projection (keeps long chains from stretching). Default `false`.
`linearBreakable`	boolean	Let the constraint break under linear force. Default `false`.
`linearBreakThreshold`	number	Force above which the constraint breaks; negative leaves it unchanged. Default `-1.0`.
`angularBreakable`	boolean	Let the constraint break under torque. Default `false`.
`angularBreakThreshold`	number	Torque above which the constraint breaks; negative leaves it unchanged. Default `-1.0`.
`parentDominates`	boolean	Let the parent body dominate the child. Default `false`.
`frameRotation`	{x,y,z}	Rotation offset applied to the constraint frame, as pitch/yaw/roll.

Returns: physicsAsset, constraints, count, message, notes.

`skel.pa_set_constraint_limits` (risk 2, mutates, smoke)

Angular and linear limits of a constraint, with the soft-limit parameters.

Argument	Type	Description
`name`	string	required. Joint name.
`swing1Motion`	string	free, limited or locked ("" leaves it unchanged).
`swing1Limit`	number	Swing 1 limit in degrees; negative leaves it unchanged. Default `-1.0`.
`swing2Motion`	string	free, limited or locked ("" leaves it unchanged).
`swing2Limit`	number	Swing 2 limit in degrees; negative leaves it unchanged. Default `-1.0`.
`twistMotion`	string	free, limited or locked ("" leaves it unchanged).
`twistLimit`	number	Twist limit in degrees; negative leaves it unchanged. Default `-1.0`.
`linearXMotion`	string	free, limited or locked ("" leaves it unchanged).
`linearYMotion`	string	free, limited or locked ("" leaves it unchanged).
`linearZMotion`	string	free, limited or locked ("" leaves it unchanged).
`linearLimit`	number	Linear limit distance; negative leaves it unchanged. Default `-1.0`.
`softSwing`	boolean	Make the swing limit soft. Default `false`.
`swingStiffness`	number	Soft swing stiffness; negative leaves it unchanged. Default `-1.0`.
`swingDamping`	number	Soft swing damping; negative leaves it unchanged. Default `-1.0`.
`softTwist`	boolean	Make the twist limit soft. Default `false`.
`twistStiffness`	number	Soft twist stiffness; negative leaves it unchanged. Default `-1.0`.
`twistDamping`	number	Soft twist damping; negative leaves it unchanged. Default `-1.0`.
`softLinear`	boolean	Make the linear limit soft. Default `false`.
`linearStiffness`	number	Soft linear stiffness; negative leaves it unchanged. Default `-1.0`.
`linearDamping`	number	Soft linear damping; negative leaves it unchanged. Default `-1.0`.

Returns: physicsAsset, constraints, count, message, notes.

`skel.pa_set_constraint_motor` (risk 2, mutates, smoke)

Angular and linear drives (motors) of a constraint.

Argument	Type	Description
`name`	string	required. Joint name.
`angularDriveMode`	string	slerp or twistAndSwing ("" leaves it unchanged).
`orientationDrive`	boolean	Enable the angular orientation drive. Default `false`.
`velocityDrive`	boolean	Enable the angular velocity drive. Default `false`.
`strength`	number	Angular drive spring strength; negative leaves it unchanged. Default `-1.0`.
`damping`	number	Angular drive damping; negative leaves it unchanged. Default `-1.0`.
`maxForce`	number	Maximum force the drives may apply; negative leaves it unchanged. Default `-1.0`.
`target`	{x,y,z}	Target orientation as pitch/yaw/roll.
`linearPositionDrive`	boolean	Enable the linear position drive on all three axes. Default `false`.
`linearVelocityDrive`	boolean	Enable the linear velocity drive on all three axes. Default `false`.

Returns: physicsAsset, constraints, count, message, notes.

`skel.pa_set_physical_animation_profile` (risk 2, mutates, smoke)

Physical animation drive strengths of one bone inside a physical animation profile.

Argument	Type	Description
`profile`	string	required. Physical animation profile name.
`bone`	string	required. Bone the settings apply to.
`orientationStrength`	number	Strength of the orientation drive. Default `0.0`.
`angularVelocityStrength`	number	Strength of the angular velocity drive. Default `0.0`.
`positionStrength`	number	Strength of the position drive. Default `0.0`.
`velocityStrength`	number	Strength of the linear velocity drive. Default `0.0`.
`maxLinearForce`	number	Maximum linear force the drives may apply. Default `0.0`.
`maxAngularForce`	number	Maximum angular force the drives may apply. Default `0.0`.
`isLocalSimulation`	boolean	Simulate in the space of the body's parent instead of world space. Default `true`.

Returns: physicsAsset, constraintProfiles, physicalAnimationProfiles, message, notes.

`skel.pa_set_physical_material` (risk 2, mutates)

Assigns a physical material to one body or to every body. Not smoke-tested: no physical material ships in engine content.

Argument	Type	Description
`bone`	string	Bone to change; every body when empty.
`material`	string	required. Physical material asset path.

Returns: physicsAsset, bodies, count, message, notes.

`skel.pa_set_preview_mesh` (risk 2, mutates, smoke)

Sets the skeletal mesh the physics asset editor previews.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: physicsAsset, message, notes.

`skel.pa_set_profile_constraint` (risk 2, mutates, smoke)

Stores constraint limits and drive strengths inside a constraint profile.

Argument	Type	Description
`profile`	string	required. Constraint profile name.
`constraint`	string	required. Joint name.
`swing1Motion`	string	free, limited or locked ("" leaves it unchanged).
`swing1Limit`	number	Swing 1 limit in degrees; negative leaves it unchanged. Default `-1.0`.
`swing2Motion`	string	free, limited or locked ("" leaves it unchanged).
`swing2Limit`	number	Swing 2 limit in degrees; negative leaves it unchanged. Default `-1.0`.
`twistMotion`	string	free, limited or locked ("" leaves it unchanged).
`twistLimit`	number	Twist limit in degrees; negative leaves it unchanged. Default `-1.0`.
`strength`	number	Angular drive spring strength; negative leaves it unchanged. Default `-1.0`.
`damping`	number	Angular drive damping; negative leaves it unchanged. Default `-1.0`.

Returns: physicsAsset, constraintProfiles, physicalAnimationProfiles, message, notes.

`skel.pa_set_shape` (risk 2, mutates, smoke)

Edits an existing collision shape.

Argument	Type	Description
`bone`	string	required. Bone the body is attached to.
`type`	string	required. box, sphere or capsule.
`index`	integer	Shape index inside its type list (skel.pa_set_shape / skel.pa_remove_shape). Default `0`.
`center`	{x,y,z}	Shape centre relative to the bone.
`rotation`	{x,y,z}	Shape rotation as pitch/yaw/roll.
`extent`	{x,y,z}	Full extents of a box shape; (0,0,0) leaves them unchanged.
`radius`	number	Radius of a sphere or capsule; negative leaves it unchanged. Default `-1.0`.
`length`	number	Length of a capsule's line segment; negative leaves it unchanged. Default `-1.0`.
`name`	string	Optional shape name.
`contributeToMass`	boolean	Whether the shape adds to the body's mass. Default `true`.

Returns: physicsAsset, bone, shapes, count, message, notes.

`skel.pa_set_solver` (risk 2, mutates, smoke)

Solver settings of the physics asset (iteration counts and solver type).

Argument	Type	Description
`positionIterations`	integer	Position iterations (UE 5) / solver iterations (UE 4.27); negative leaves it unchanged. Default `-1`.
`velocityIterations`	integer	Velocity iterations (UE 5) / joint iterations (UE 4.27); negative leaves it unchanged. Default `-1`.
`projectionIterations`	integer	Projection iterations (UE 5) / collision iterations (UE 4.27); negative leaves it unchanged. Default `-1`.
`solverType`	string	World or RBAN ("" leaves it unchanged).

Returns: physicsAsset, message, notes.

`skel.pa_validate` (risk 0, smoke)

Sanity check: bodies without shapes, constraints pointing at missing bodies, bones without a body.

Argument	Type	Description
`physicsAsset`	string	required. Physics asset path or unique name.

Returns: physicsAsset, errors, warnings, valid, message.

`skel.pa_weld_bodies` (risk 3, mutates)

Merges the body of a child bone into its parent's. Not smoke-tested: it needs a live skeletal mesh component.

Argument	Type	Description
`parent`	string	required. Bone that keeps its body.
`child`	string	required. Bone whose body is merged into the parent's.

Returns: physicsAsset, bodies, count, message, notes.

`skel.rebuild_mesh` (risk 2, mutates, smoke)

Rebuilds the mesh's render data after low-level edits.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, message, lods, notes.

`skel.recreate_bone_tree` (risk 3, mutates, destructive, smoke)

Rebuilds the bone tree from a mesh, discarding the current hierarchy (breaks existing animations).

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: skeleton, message, notes.

`skel.regenerate_lod` (risk 3, mutates)

Regenerates one LOD from its reduction settings. Not smoke-tested: skeletal reduction needs a mesh reduction plugin the smoke project does not enable.

Argument	Type	Description
`lod`	integer	required. LOD index (0-based).

Returns: mesh, lods, count, message, notes.

`skel.reimport_mesh` (risk 3, mutates)

Reimports the mesh from its source file (or from a new one). Not smoke-tested: it needs an FBX file on disk.

Argument	Type	Description
`file`	string	Source file to reimport from ("" uses the stored one).

Returns: mesh, message, lods, notes.

`skel.remove_all_morph_targets` (risk 3, mutates, destructive, smoke)

Removes every morph target of a skeletal mesh.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, morphTargets, count, message, notes.

`skel.remove_blend_profile` (risk 3, mutates, destructive, smoke)

Deletes a blend profile.

Argument	Type	Description
`name`	string	required. Name to operate on.

Returns: skeleton, profiles, count, message, notes.

`skel.remove_compatible_skeleton` (risk 2, mutates, UE 5.0+, smoke)

Removes a skeleton from the compatible list (UE 5 only).

Argument	Type	Description
`other`	string	required. The other skeleton asset path or unique name.

Returns: skeleton, names, count, message, notes.

`skel.remove_curve` (risk 3, mutates, destructive, smoke)

Removes a curve and its metadata from the skeleton.

Argument	Type	Description
`name`	string	required. Name to operate on.

Returns: skeleton, curves, count, message, notes.

`skel.remove_lod` (risk 3, mutates, destructive)

Removes one LOD. Not smoke-tested: the engine cube fixture only has LOD0 and LOD removal needs a reduction plugin.

Argument	Type	Description
`lod`	integer	required. LOD index (0-based).

Returns: mesh, lods, count, message, notes.

`skel.remove_material_slot` (risk 3, mutates, destructive, smoke)

Removes a material slot; refused while a section still uses it.

Argument	Type	Description
`slot`	string	required. Slot index or slot name.

Returns: mesh, materials, count, message, notes.

`skel.remove_morph_target` (risk 3, mutates, destructive)

Removes one morph target. Not smoke-tested: the engine cube fixture has no morph targets.

Argument	Type	Description
`name`	string	required. Name to operate on.

Returns: mesh, morphTargets, count, message, notes.

`skel.remove_notify_name` (risk 2, mutates, smoke)

Removes a notify name from the skeleton's cached list.

Argument	Type	Description
`name`	string	required. Name to operate on.

Returns: skeleton, names, count, message, notes.

`skel.remove_skeleton_socket` (risk 3, mutates, destructive, smoke)

Removes a socket from the skeleton.

Argument	Type	Description
`name`	string	required. Name to operate on.

Returns: skeleton, sockets, count, message, notes.

`skel.remove_skin_weight_profile` (risk 3, mutates, destructive, UE 5.0+)

Removes a skin weight profile (UE 5 only; UE 4.27 has no removal API). Not smoke-tested: the engine cube fixture has no skin weight profiles.

Argument	Type	Description
`name`	string	required. Name to operate on.

Returns: mesh, profiles, count, message, notes.

`skel.remove_slot` (risk 3, mutates, destructive, smoke)

Removes an animation slot.

Argument	Type	Description
`slot`	string	Slot name (skel.add_slot, skel.set_slot_group, skel.remove_slot).
`group`	string	Slot group name (defaults to DefaultGroup for skel.add_slot).

Returns: skeleton, groups, count, message, notes.

`skel.remove_virtual_bones` (risk 3, mutates, destructive, smoke)

Removes virtual bones by name.

Argument	Type	Description
`names`	array of string	required. Names to operate on.

Returns: skeleton, virtualBones, count, createdName, message, notes.

`skel.rename_curve` (risk 2, mutates, smoke)

Renames a curve.

Argument	Type	Description
`name`	string	required. Current name.
`newName`	string	required. New name.

Returns: skeleton, curves, count, message, notes.

`skel.rename_morph_target` (risk 2, mutates)

Renames a morph target. Not smoke-tested: the engine cube fixture has no morph targets.

Argument	Type	Description
`name`	string	required. Current name.
`newName`	string	required. New name.

Returns: mesh, morphTargets, count, message, notes.

`skel.rename_virtual_bone` (risk 2, mutates, smoke)

Renames a virtual bone.

Argument	Type	Description
`name`	string	required. Current name.
`newName`	string	required. New name.

Returns: skeleton, virtualBones, count, createdName, message, notes.

`skel.reset_ref_pose` (risk 3, mutates, smoke)

Resets the mesh's reference pose to the skeleton's one.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, space, bones, count, message, notes.

`skel.save_mesh` (risk 1)

Saves the skeletal mesh package to disk. Not smoke-tested: the self-test never writes to disk.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, message, lods, notes.

`skel.save_skeleton` (risk 1)

Saves the skeleton package to disk.

Argument	Type	Description
`skeleton`	string	required. Skeleton asset path or unique name.

Returns: skeleton, message, notes.

`skel.set_allow_cpu_access` (risk 2, mutates, smoke)

Keeps the mesh's vertex buffers readable on the CPU (needed by some Niagara and trace setups).

Argument	Type	Description
`enabled`	boolean	Value of the flag. Default `true`.

Returns: mesh, message, lods, notes.

`skel.set_blend_profile_bone` (risk 2, mutates, smoke)

Sets the blend scale of one bone (optionally its whole subtree) in a blend profile.

Argument	Type	Description
`profile`	string	required. Blend profile name.
`bone`	string	required. Bone name.
`scale`	number	required. Blend scale (1 = normal speed/weight, 0 = the bone does not blend).
`recurse`	boolean	Also apply the scale to every descendant of the bone. Default `false`.

Returns: skeleton, profiles, count, message, notes.

`skel.set_bounds` (risk 2, mutates, smoke)

Extra padding added to the rendered bounds (fixes meshes that disappear when animated).

Argument	Type	Description
`positiveExtension`	{x,y,z}	Padding added on +X/+Y/+Z.
`negativeExtension`	{x,y,z}	Padding added on -X/-Y/-Z.

Returns: mesh, message, lods, notes.

`skel.set_curve_metadata` (risk 2, mutates, smoke)

Updates the metadata of an existing curve (morph target / material flags, max LOD, linked bones).

Argument	Type	Description
`name`	string	required. Curve name.
`morphTarget`	boolean	Mark the curve as driving a morph target. Default `false`.
`material`	boolean	Mark the curve as driving a material parameter. Default `false`.
`maxLod`	integer	Lowest-detail LOD the curve is still evaluated on; -1 leaves it unchanged, 255 = always. Default `-1`.
`linkedBones`	array of string	Bones the curve is linked to (skel.set_curve_metadata only; empty leaves them unchanged).

Returns: skeleton, curves, count, message, notes.

`skel.set_default_mesh_deformer` (risk 2, mutates, UE 5.1+, smoke)

Assigns (or clears) the default mesh deformer (UE 5.1+ deformer graph).

Argument	Type	Description
`asset`	string	Asset path; "" clears the reference.

Returns: mesh, message, lods, notes.

`skel.set_import_settings` (risk 2, mutates, smoke)

Edits the FBX import settings stored on the mesh (they apply to the next reimport).

Argument	Type	Description
`importMorphTargets`	boolean	Import morph targets on the next reimport. Default `true`.
`updateSkeletonReferencePose`	boolean	Update the skeleton's reference pose from the file. Default `false`.
`useT0AsRefPose`	boolean	Use frame 0 of the file as the reference pose. Default `false`.
`preserveSmoothingGroups`	boolean	Keep the file's smoothing groups. Default `true`.
`importMeshesInBoneHierarchy`	boolean	Import meshes that live inside the bone hierarchy. Default `true`.
`thresholdPosition`	number	Weld distance for positions; negative leaves it unchanged. Default `-1.0`.
`thresholdTangentNormal`	number	Weld threshold for tangents/normals; negative leaves it unchanged. Default `-1.0`.
`thresholdUv`	number	Weld threshold for UVs; negative leaves it unchanged. Default `-1.0`.
`normalImportMethod`	string	ComputeNormals / ImportNormals / ImportNormalsAndTangents ("" leaves it unchanged).
`normalGenerationMethod`	string	BuiltIn / MikkTSpace ("" leaves it unchanged).
`computeWeightedNormals`	boolean	Weight generated normals by triangle area. Default `false`.

Returns: mesh, importDataClass, settings, sourceFiles, canReimport, message, notes.

`skel.set_lod_build_settings` (risk 2, mutates, smoke)

Edits the build settings of one LOD (normals, tangents, MikkTSpace, welding thresholds).

Argument	Type	Description
`lod`	integer	required. LOD index.
`recomputeNormals`	boolean	Recompute normals when building. Default `false`.
`recomputeTangents`	boolean	Recompute tangents when building. Default `true`.
`useMikkTSpace`	boolean	Use MikkTSpace to generate tangents. Default `true`.
`computeWeightedNormals`	boolean	Weight generated normals by triangle area. Default `false`.
`removeDegenerates`	boolean	Drop degenerate triangles. Default `true`.
`useHighPrecisionTangentBasis`	boolean	Store tangents with higher precision. Default `false`.
`useFullPrecisionUVs`	boolean	Store UVs with full precision. Default `false`.
`thresholdPosition`	number	Weld distance for positions; negative leaves it unchanged. Default `-1.0`.
`thresholdTangentNormal`	number	Weld threshold for tangents/normals; negative leaves it unchanged. Default `-1.0`.
`thresholdUv`	number	Weld threshold for UVs; negative leaves it unchanged. Default `-1.0`.
`rebuild`	boolean	Rebuild the mesh after the change. Default `false`.

Returns: mesh, lods, count, message, notes.

`skel.set_lod_info` (risk 2, mutates, smoke)

Edits the LOD info of one LOD: screen size, hysteresis, CPU access, sampling, bake pose, bones to remove/prioritize.

Argument	Type	Description
`lod`	integer	required. LOD index (0-based).
`screenSize`	number	Screen size at which the LOD becomes active; negative leaves it unchanged. Default `-1.0`.
`hysteresis`	number	LOD hysteresis; negative leaves it unchanged. Default `-1.0`.
`allowCpuAccess`	boolean	Keep the LOD's vertex buffers readable on the CPU. Default `false`.
`supportUniformSampling`	boolean	Support uniformly distributed sampling (Niagara). Default `false`.
`bakePose`	string	Animation whose pose is baked into the LOD ("" clears it, omitted leaves it unchanged).
`bakePoseOverride`	string	Animation whose pose overrides the baked one.
`bonesToRemove`	array of string	Bones removed at this LOD (replaces the current list when non-empty).
`bonesToPrioritize`	array of string	Bones the reduction tries to preserve (replaces the current list when non-empty).
`weightOfPrioritization`	number	Weight given to the prioritized bones; negative leaves it unchanged. Default `-1.0`.
`rebuild`	boolean	Rebuild the mesh after the change (slower, but the result is immediately visible). Default `false`.

Returns: mesh, lods, count, message, notes.

`skel.set_lod_reduction` (risk 2, mutates, smoke)

Edits the reduction settings of one LOD (termination criterion, percentages, deviation, bone limits).

Argument	Type	Description
`lod`	integer	required. LOD index (0-based).
`terminationCriterion`	string	NumOfTriangles, NumOfVerts, NumOfTrianglesPercent, NumOfVertsPercent... ("" leaves it unchanged).
`percentTriangles`	number	Fraction of triangles to keep (0-1); negative leaves it unchanged. Default `-1.0`.
`percentVertices`	number	Fraction of vertices to keep (0-1); negative leaves it unchanged. Default `-1.0`.
`maxDeviation`	number	Maximum deviation in percent; negative leaves it unchanged. Default `-1.0`.
`maxBonesPerVertex`	integer	Maximum bone influences per vertex; negative leaves it unchanged. Default `-1`.
`weldingThreshold`	number	Distance below which vertices are welded; negative leaves it unchanged. Default `-1.0`.
`hardAngle`	number	Normal split angle in degrees; negative leaves it unchanged. Default `-1.0`.
`baseLod`	integer	LOD the reduction reads from; negative leaves it unchanged. Default `-1`.
`lockEdges`	boolean	Keep boundary edges. Default `false`.
`enforceBoneBoundaries`	boolean	Do not collapse vertices across bone boundaries. Default `false`.
`rebuild`	boolean	Rebuild the mesh after the change. Default `false`.

Returns: mesh, lods, count, message, notes.

`skel.set_lod_settings_asset` (risk 2, mutates)

Assigns a SkeletalMeshLODSettings asset and optionally copies its settings into the LOD infos. Not smoke-tested: no LOD settings asset ships in engine content.

Argument	Type	Description
`settings`	string	SkeletalMeshLODSettings asset path; "" clears it.
`apply`	boolean	Immediately copy the settings into the mesh's LOD infos. Default `true`.

Returns: mesh, lods, count, message, notes.

`skel.set_min_lod_per_platform` (risk 2, mutates, smoke)

Minimum LOD with per-platform overrides and the below-minimum stripping switch.

Argument	Type	Description
`minLod`	integer	required. Default minimum LOD the renderer may use.
`perPlatform`	array of UeaKeyValue	Per-platform overrides as "platform=lod" (e.g. "Mobile=2").
`disableBelowMinLodStripping`	boolean	Keep the LODs below the minimum in cooked builds. Default `false`.

Returns: mesh, message, lods, notes.

`skel.set_physics_assets` (risk 2, mutates, smoke)

Assigns the physics asset and the shadow physics asset in one call.

Argument	Type	Description
`physicsAsset`	string	Physics asset path; "" clears it.
`shadowPhysicsAsset`	string	Cheaper physics asset used for shadow computations; "" clears it.

Returns: mesh, message, lods, notes.

`skel.set_post_process_anim_blueprint` (risk 2, mutates, smoke)

Assigns (or clears) the post-process animation blueprint run after the main anim graph.

Argument	Type	Description
`asset`	string	Asset path; "" clears the reference.

Returns: mesh, message, lods, notes.

`skel.set_preview_mesh` (risk 2, mutates, smoke)

Sets the mesh shown when the skeleton is opened in Persona.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: skeleton, message, notes.

`skel.set_ray_tracing` (risk 2, mutates, smoke)

Whether a ray tracing acceleration structure is built for the mesh, and from which LOD.

Argument	Type	Description
`support`	boolean	required. Build a ray tracing acceleration structure for this mesh.
`minLod`	integer	Lowest LOD used by ray tracing (UE 5 only); negative leaves it unchanged. Default `-1`.

Returns: mesh, message, lods, notes.

`skel.set_ref_pose_bone` (risk 3, mutates, smoke)

Moves one bone of the mesh's reference pose. Breaks existing animations and invalidates the physics asset.

Argument	Type	Description
`bone`	string	required. Bone name.
`location`	{x,y,z}	New translation relative to the parent bone.
`rotation`	{x,y,z}	New rotation relative to the parent bone, as pitch/yaw/roll.
`scale`	{x,y,z}	New scale; (0,0,0) means 1,1,1.
`rebuild`	boolean	Rebuild the mesh after the change. Default `true`.

Returns: mesh, space, bones, count, message, notes.

`skel.set_retarget_mode` (risk 2, mutates, smoke)

Sets the translation retargeting mode of a bone (Animation, Skeleton, AnimationScaled, AnimationRelative, OrientAndScale).

Argument	Type	Description
`bone`	string	required. Bone name.
`mode`	string	required. Animation, Skeleton, AnimationScaled, AnimationRelative or OrientAndScale.
`recurse`	boolean	Also apply the mode to every descendant of the bone. Default `false`.

Returns: skeleton, modes, count, changed, message, notes.

`skel.set_sampling_regions` (risk 2, mutates, smoke)

Replaces the Niagara sampling regions of a skeletal mesh (an empty list clears them).

Argument	Type	Description
`regions`	array of UeaSkelSamplingRegion	The regions; an empty array clears them.

Returns: mesh, message, lods, notes.

`skel.set_section` (risk 2, mutates, smoke)

Edits one section of a LOD: material slot, disabled, cast shadow, recompute tangent, ray tracing visibility, generate-up-to LOD.

Argument	Type	Description
`lod`	integer	required. LOD index.
`section`	integer	required. Section index inside the LOD.
`materialSlot`	integer	Material slot the section draws with; negative leaves it unchanged. Default `-1`.
`disabled`	boolean	Skip the section in the renderer. Default `false`.
`castShadow`	boolean	Section casts shadows. Default `true`.
`recomputeTangent`	boolean	Recompute tangents every frame (needed by some cloth/morph setups). Default `false`.
`visibleInRayTracing`	boolean	Section is visible to ray tracing (UE 5 only). Default `true`.
`generateUpToLod`	integer	The section disappears past this LOD; negative leaves it unchanged. Default `-1`.

Returns: mesh, sections, count, message, notes.

`skel.set_skeleton_socket` (risk 2, mutates, smoke)

Changes an existing skeleton socket (bone, transform, name).

Argument	Type	Description
`name`	string	required. Socket name.
`bone`	string	Bone the socket is attached to (required when adding).
`location`	{x,y,z}	Offset from the bone.
`rotation`	{x,y,z}	Rotation as pitch/yaw/roll.
`scale`	{x,y,z}	Scale; (0,0,0) means 1,1,1.
`forceAlwaysAnimated`	boolean	Keep the socket's bone animated even when it is not otherwise required. Default `false`.
`newName`	string	New socket name (skel.set_skeleton_socket only).

Returns: skeleton, sockets, count, message, notes.

`skel.set_skin_weight_profile` (risk 2, mutates)

Changes the flags of a skin weight profile. Not smoke-tested: the engine cube fixture has no skin weight profiles.

Argument	Type	Description
`name`	string	required. Profile name.
`defaultProfile`	boolean	Make the profile replace the default skin weights. Default `false`.
`defaultProfileFromLod`	integer	LOD index from which the profile overrides the default weights. Default `0`.

Returns: mesh, profiles, count, message, notes.

`skel.set_slot_group` (risk 2, mutates, smoke)

Moves an existing slot to another group.

Argument	Type	Description
`slot`	string	Slot name (skel.add_slot, skel.set_slot_group, skel.remove_slot).
`group`	string	Slot group name (defaults to DefaultGroup for skel.add_slot).

Returns: skeleton, groups, count, message, notes.

`skel.set_source_file` (risk 2, mutates)

Points the mesh at another source file for the next reimport. Not smoke-tested: it needs an FBX file on disk.

Argument	Type	Description
`asset`	string	Asset path; "" clears the reference.

Returns: mesh, message, lods, notes.

`skel.set_vertex_color_lod` (risk 3, mutates, smoke)

Paints every vertex of a LOD with one colour (useful to prime a vertex colour channel).

Argument	Type	Description
`lod`	integer	required. LOD index.
`color`	string	required. Colour as "#RRGGBB", "#RRGGBBAA" or "R,G,B,A" with 0-255 components.

Returns: mesh, message, lods, notes.

`skel.strip_lod_geometry` (risk 3, mutates)

Strips the geometry of a LOD using a texture mask. Not smoke-tested: it needs a mask texture and a reducible mesh.

Argument	Type	Description
`lod`	integer	required. LOD index.
`textureMask`	string	required. Texture asset used as the mask.
`threshold`	number	Threshold above which a triangle is kept (0-1). Default `0.5`.

Returns: mesh, lods, count, message, notes.

`skel.validate_mesh` (risk 0, smoke)

Sanity check: missing skeleton, sections without a material, LOD ordering, degenerate bounds, physics asset mismatch.

Argument	Type	Description
`mesh`	string	required. Skeletal mesh asset path or unique name.

Returns: mesh, errors, warnings, valid, message.

Guide
Start here
Recipes
Gotchas
Tools

Guide​

Start here​

Recipes​

Ragdoll from scratch​

Mirroring a half-built physics asset​

Retarget-ready skeleton​

LOD chain and section cleanup​

Morph target management​

Mesh merge for modular characters​

Cloth​

Folder-wide work​

Gotchas​

Tools​

skel.add_compatible_skeleton (risk 2, mutates, UE 5.0+, smoke)​

skel.add_curve (risk 2, mutates, smoke)​

skel.add_material_slot (risk 2, mutates, smoke)​

skel.add_notify_name (risk 2, mutates, smoke)​

skel.add_skeleton_socket (risk 2, mutates, smoke)​

skel.add_slot (risk 2, mutates, smoke)​

skel.add_slot_group (risk 2, mutates, smoke)​

skel.add_virtual_bone (risk 2, mutates, smoke)​

skel.apply_retarget_preset (risk 2, mutates, smoke)​

skel.audit_meshes (risk 0, smoke)​

skel.audit_physics_assets (risk 0, smoke)​

skel.audit_skeletons (risk 0, smoke)​

skel.batch_regenerate_lods (risk 3, mutates, destructive)​

skel.batch_retarget_modes (risk 3, mutates, smoke)​

skel.batch_set_lod_settings (risk 3, mutates, smoke)​

skel.batch_set_physics_asset (risk 3, mutates, smoke)​

skel.batch_set_skeleton (risk 3, mutates, destructive, smoke)​

skel.cloth_bind (risk 2, mutates, requires plugin ChaosCloth)​

skel.cloth_create_from_section (risk 3, mutates, requires plugin ChaosCloth)​

skel.cloth_get (risk 0, requires plugin ChaosCloth)​

skel.cloth_get_config (risk 0, requires plugin ChaosCloth)​

skel.cloth_get_section_binding (risk 0, requires plugin ChaosCloth)​

skel.cloth_list (risk 0, requires plugin ChaosCloth)​

skel.cloth_list_weight_maps (risk 0, requires plugin ChaosCloth)​

skel.cloth_rebuild (risk 2, mutates, requires plugin ChaosCloth)​

skel.cloth_remove (risk 3, mutates, destructive, requires plugin ChaosCloth)​

skel.cloth_set_config (risk 2, mutates, requires plugin ChaosCloth)​

skel.cloth_set_weight_map_value (risk 3, mutates, requires plugin ChaosCloth)​

skel.cloth_unbind (risk 2, mutates, requires plugin ChaosCloth)​

skel.copy_lod_settings (risk 2, mutates, smoke)​

skel.copy_morph_targets (risk 2, mutates, smoke)​

skel.create_blend_profile (risk 2, mutates, smoke)​

skel.create_test_mesh (risk 2, mutates, smoke)​

skel.duplicate_mesh (risk 2, mutates, smoke)​

skel.export_fbx (risk 1)​

skel.find_bones (risk 0, smoke)​

skel.generate_lods (risk 3, mutates)​

skel.get_bone (risk 0, smoke)​

skel.get_bone_chain (risk 0, smoke)​

skel.get_bone_influences (risk 0, smoke)​

skel.get_import_settings (risk 0, smoke)​

skel.get_lod_build_settings (risk 0, smoke)​

skel.get_lod_info (risk 0, smoke)​

skel.get_mesh (risk 0, smoke)​

skel.get_ref_pose (risk 0, smoke)​

skel.get_required_bones (risk 0, smoke)​

skel.get_retarget_modes (risk 0, smoke)​

skel.get_skeleton (risk 0, smoke)​

skel.get_vertex_info (risk 0, smoke)​

skel.import_lod (risk 3, mutates)​

skel.is_mesh_compatible (risk 0, smoke)​

skel.list_animations_using_skeleton (risk 0, smoke)​

skel.list_blend_profiles (risk 0, smoke)​

skel.list_bones (risk 0, smoke)​

skel.list_compatible_skeletons (risk 0, UE 5.0+, smoke)​

skel.list_curves (risk 0, smoke)​

skel.list_material_slots (risk 0, smoke)​

skel.list_meshes_using_skeleton (risk 0, smoke)​

skel.list_morph_targets (risk 0, smoke)​

skel.list_notify_names (risk 0, smoke)​

skel.list_sections (risk 0, smoke)​

skel.list_skeleton_sockets (risk 0, smoke)​

skel.list_skeletons (risk 0, smoke)​

skel.list_skin_weight_profiles (risk 0, smoke)​

skel.list_slot_groups (risk 0, smoke)​

skel.list_virtual_bones (risk 0, smoke)​

skel.merge_bones_from_mesh (risk 2, mutates, smoke)​

Guide

Start here

Recipes

Ragdoll from scratch

Mirroring a half-built physics asset

Retarget-ready skeleton

LOD chain and section cleanup

Morph target management

Mesh merge for modular characters

Cloth

Folder-wide work

Gotchas

Tools

`skel.add_compatible_skeleton` (risk 2, mutates, UE 5.0+, smoke)

`skel.add_curve` (risk 2, mutates, smoke)

`skel.add_material_slot` (risk 2, mutates, smoke)

`skel.add_notify_name` (risk 2, mutates, smoke)

`skel.add_skeleton_socket` (risk 2, mutates, smoke)

`skel.add_slot` (risk 2, mutates, smoke)

`skel.add_slot_group` (risk 2, mutates, smoke)

`skel.add_virtual_bone` (risk 2, mutates, smoke)

`skel.apply_retarget_preset` (risk 2, mutates, smoke)

`skel.audit_meshes` (risk 0, smoke)

`skel.audit_physics_assets` (risk 0, smoke)

`skel.audit_skeletons` (risk 0, smoke)

`skel.batch_regenerate_lods` (risk 3, mutates, destructive)

`skel.batch_retarget_modes` (risk 3, mutates, smoke)

`skel.batch_set_lod_settings` (risk 3, mutates, smoke)

`skel.batch_set_physics_asset` (risk 3, mutates, smoke)

`skel.batch_set_skeleton` (risk 3, mutates, destructive, smoke)

`skel.cloth_bind` (risk 2, mutates, requires plugin ChaosCloth)

`skel.cloth_create_from_section` (risk 3, mutates, requires plugin ChaosCloth)

`skel.cloth_get` (risk 0, requires plugin ChaosCloth)

`skel.cloth_get_config` (risk 0, requires plugin ChaosCloth)

`skel.cloth_get_section_binding` (risk 0, requires plugin ChaosCloth)

`skel.cloth_list` (risk 0, requires plugin ChaosCloth)

`skel.cloth_list_weight_maps` (risk 0, requires plugin ChaosCloth)

`skel.cloth_rebuild` (risk 2, mutates, requires plugin ChaosCloth)

`skel.cloth_remove` (risk 3, mutates, destructive, requires plugin ChaosCloth)

`skel.cloth_set_config` (risk 2, mutates, requires plugin ChaosCloth)

`skel.cloth_set_weight_map_value` (risk 3, mutates, requires plugin ChaosCloth)

`skel.cloth_unbind` (risk 2, mutates, requires plugin ChaosCloth)

`skel.copy_lod_settings` (risk 2, mutates, smoke)

`skel.copy_morph_targets` (risk 2, mutates, smoke)

`skel.create_blend_profile` (risk 2, mutates, smoke)

`skel.create_test_mesh` (risk 2, mutates, smoke)

`skel.duplicate_mesh` (risk 2, mutates, smoke)

`skel.export_fbx` (risk 1)

`skel.find_bones` (risk 0, smoke)

`skel.generate_lods` (risk 3, mutates)

`skel.get_bone` (risk 0, smoke)

`skel.get_bone_chain` (risk 0, smoke)

`skel.get_bone_influences` (risk 0, smoke)

`skel.get_import_settings` (risk 0, smoke)

`skel.get_lod_build_settings` (risk 0, smoke)

`skel.get_lod_info` (risk 0, smoke)

`skel.get_mesh` (risk 0, smoke)

`skel.get_ref_pose` (risk 0, smoke)

`skel.get_required_bones` (risk 0, smoke)

`skel.get_retarget_modes` (risk 0, smoke)

`skel.get_skeleton` (risk 0, smoke)

`skel.get_vertex_info` (risk 0, smoke)

`skel.import_lod` (risk 3, mutates)

`skel.is_mesh_compatible` (risk 0, smoke)

`skel.list_animations_using_skeleton` (risk 0, smoke)

`skel.list_blend_profiles` (risk 0, smoke)

`skel.list_bones` (risk 0, smoke)

`skel.list_compatible_skeletons` (risk 0, UE 5.0+, smoke)

`skel.list_curves` (risk 0, smoke)

`skel.list_material_slots` (risk 0, smoke)

`skel.list_meshes_using_skeleton` (risk 0, smoke)

`skel.list_morph_targets` (risk 0, smoke)

`skel.list_notify_names` (risk 0, smoke)

`skel.list_sections` (risk 0, smoke)

`skel.list_skeleton_sockets` (risk 0, smoke)

`skel.list_skeletons` (risk 0, smoke)

`skel.list_skin_weight_profiles` (risk 0, smoke)

`skel.list_slot_groups` (risk 0, smoke)

`skel.list_virtual_bones` (risk 0, smoke)

`skel.merge_bones_from_mesh` (risk 2, mutates, smoke)