HumanoidRetargeter/Mapping/ProfileLibrary.cs

A static library of builtin humanoid rig mapping profiles. It constructs Profile instances for many common skeleton naming conventions (Mixamo, ActorCore, UE mannequin, BVH formats, SMPL/SMPL-X, Rigify, VRM, Auto-Rig Pro, etc.) with regex namespace patterns and bone-role-to-name-alias dictionaries.

Reflection
using System.Collections.Generic;

namespace HumanoidRetargeter.Mapping;

/// <summary>
/// Built-in preset profiles, embedded as C# data (the same data is written to
/// <c>Assets/humanoid_retargeter/profiles/*.json</c> by a regenerate-and-diff test so the
/// shipped JSON can never drift from the code).
/// </summary>
public static class ProfileLibrary
{
    /// <summary>Mixamo / Adobe rigs: <c>mixamorig[N]:</c> namespace, <c>LeftArm</c> /
    /// <c>LeftForeArm</c> / <c>LeftHandIndex1..3</c> style names.</summary>
    public static Profile Mixamo { get; } = BuildMixamo();

    /// <summary>
    /// Reallusion ActorCore / AccuRig / Character Creator rigs (<c>CC_Base_*</c>).
    /// Empirical notes from <c>research/rig_actorcore.json</c>:
    /// <list type="bullet">
    /// <item><c>CC_Base_Hip</c> is the parent of BOTH <c>CC_Base_Pelvis</c> (leg branch) and
    /// <c>CC_Base_Waist</c> (spine branch), i.e. the LCA of legs+spine and the true animated
    /// hips root → it carries <see cref="BoneRole.Hips"/>; <c>CC_Base_Pelvis</c> is a
    /// leg-branch intermediate and stays unmapped.</item>
    /// <item>The neck chain is <c>CC_Base_NeckTwist01 → CC_Base_NeckTwist02 → CC_Base_Head</c>;
    /// despite the name, <c>NeckTwist01</c> IS the neck bone (there is no plain
    /// <c>CC_Base_Neck</c>), so it is the <see cref="BoneRole.Neck"/> alias. NeckTwist02 is
    /// left unmapped. All other Twist/ShareBone helpers are excluded (no aliases).</item>
    /// <item><c>CC_Base_L_ToeBase</c> is the toe role; the co-located
    /// <c>CC_Base_L_ToeBaseShareBone</c> is a helper and must never be mapped.</item>
    /// </list>
    /// </summary>
    public static Profile ActorCoreCc { get; } = BuildActorCoreCc();

    /// <summary>Unreal Engine mannequin (UE4/UE5): <c>pelvis</c>, <c>spine_01..05</c>,
    /// <c>clavicle_l</c>, <c>thumb_01_l</c>, UE5 <c>*_metacarpal_*</c>; <c>*_twist_*</c>
    /// bones have no aliases and are never mapped.</summary>
    public static Profile UeMannequin { get; } = BuildUeMannequin();

    /// <summary>Rokoko / Xsens style BVH rigs: plain <c>Hips</c>/<c>Spine..Spine4</c>/<c>
    /// LeftArm|LeftUpperArm</c> name variants, usually no fingers.</summary>
    public static Profile RokokoBvh { get; } = BuildRokokoBvh();

    /// <summary>
    /// SMPL body model family (AMASS exports, Meshcapade FBX rigs). Joint names per the
    /// published model (vchoutas/smplx <c>joint_names.py</c>, Meshcapade wiki):
    /// <c>pelvis</c>, sided <c>hip→knee→ankle→foot</c> legs (the "hip" joint IS the thigh;
    /// "ankle" is the foot, "foot" is the toe region) and <c>collar→shoulder→elbow→wrist</c>
    /// arms ("shoulder" is the upper arm, "wrist" is the hand; the <c>hand</c> joint is a
    /// finger stub and stays unmapped). Both spellings occur in the wild: <c>left_hip</c>
    /// (model joints) and <c>L_Hip</c> with gendered FBX prefixes <c>m_avg_</c>/<c>f_avg_</c>
    /// (SMPL Unity/FBX rigs). No fingers — that is SMPL-X (<see cref="SmplX"/>), kept as a
    /// separate preset so a finger-less SMPL rig still reaches full optional coverage.
    /// </summary>
    public static Profile Smpl { get; } = BuildSmpl(withFingers: false);

    /// <summary>
    /// SMPL-X: the SMPL body joints (<see cref="Smpl"/>) plus articulated hands —
    /// <c>left_thumb1..3</c>/<c>left_index1..3</c>-style finger joints per
    /// vchoutas/smplx <c>joint_names.py</c> (jaw/eye joints carry no humanoid role).
    /// Evaluated before <see cref="Smpl"/> so it wins the tie on SMPL-X rigs (both score
    /// the body fully; only this one maps the fingers).
    /// </summary>
    public static Profile SmplX { get; } = BuildSmpl(withFingers: true);

    /// <summary>
    /// NVIDIA SOMA uniform-proportion skeleton (SOMA/SEED BVH exports, e.g.
    /// github.com/NVIDIA/soma-retargeter <c>assets/motions/bvh</c>). Mixamo-identical
    /// upper-body and finger names, but: spine is <c>Spine1→Spine2→Chest</c> (no plain
    /// "Spine"), neck is <c>Neck1→Neck2</c>, and the legs are <c>LeftLeg→LeftShin</c> —
    /// SOMA's <c>LeftLeg</c> is the THIGH (mixamo's is the calf), which is exactly why the
    /// mixamo preset must never claim these rigs.
    /// </summary>
    public static Profile SomaBvh { get; } = BuildSomaBvh();

    /// <summary>
    /// Classic BVH / Character-Studio-friendly naming (MotionBuilder "Export BVH to
    /// Character Studio" convention, ACCAD-style mocap BVHs): <c>Hips</c>,
    /// <c>Chest[2..4]</c> spine, arms <c>Collar→Shoulder→Elbow→Wrist</c> (the "Shoulder"
    /// is the upper arm) and legs <c>Hip→Knee→Ankle→Toe</c> (the sided "Hip" is the
    /// thigh). No fingers.
    /// </summary>
    public static Profile ClassicBvh { get; } = BuildClassicBvh();

    /// <summary>
    /// 3ds Max Character Studio Biped rigs: every bone is "&lt;BipedName&gt; &lt;Part&gt;"
    /// where the biped name defaults to <c>Bip01</c> (3ds Max ≤2009) / <c>Bip001</c>
    /// (2010+) per the Autodesk "Naming the Biped" documentation; some exporters mangle
    /// the spaces to underscores (<c>Bip01_L_Thigh</c>), hence the <c>^Bip\d+[ _]</c>
    /// namespace pattern (alias comparison is separator-insensitive, so "L UpperArm" and
    /// "L_UpperArm" normalize identically). Sided bones use a bare mid-name <c>L/R</c>:
    /// <c>L Clavicle→L UpperArm→L Forearm→L Hand</c> arms,
    /// <c>L Thigh→L Calf→L Foot→L Toe0</c> legs. Fingers are numbered chains
    /// <c>L Finger0..4</c> (0 = thumb) with phalanx segments <c>Finger01/Finger02</c>
    /// etc. (MotionBuilder's "3ds Max Biped Template" characterization maps exactly these
    /// names). The COM root <c>Bip01</c> itself, <c>Footsteps</c>, toe segments
    /// <c>Toe01/Toe02</c> and <c>HorseLink</c> carry no aliases and are never mapped.
    /// </summary>
    public static Profile Biped { get; } = BuildBiped();

    /// <summary>
    /// DAZ/Poser classic naming (Poser 4 era figures, DAZ Generation-4 V4/M4, Genesis 1/2,
    /// MakeHuman's "Poser/DAZ names" BVH export — verified against the local
    /// <c>dev/corpus/unknown_rigs/makehuman_cmu_03_03_dazNames.bvh</c>): camel-case bones
    /// with a lower-case <c>l</c>/<c>r</c> side prefix — <c>hip</c> (the translating
    /// root), <c>abdomen[→abdomen2]→chest</c> spine, <c>neck</c>, <c>head</c>,
    /// <c>lCollar→lShldr→lForeArm→lHand</c> arms, <c>lThigh→lShin→lFoot→lToe</c> legs and
    /// <c>lThumb1..3/lIndex1..3/lMid1..3/lRing1..3/lPinky1..3</c> fingers. The
    /// <c>l/rButtock</c> thigh helpers and eye bones carry no aliases and stay unmapped.
    /// DAZ Genesis 3/8/9 renamed the skeleton (<c>abdomenLower</c>, <c>lShldrBend</c>, …)
    /// and is NOT covered by this preset.
    /// </summary>
    public static Profile DazPoser { get; } = BuildDazPoser();

    /// <summary>
    /// Blender Rigify human rigs, per the metarig definition in the rigify add-on
    /// (<c>rigify/metarigs/human.py</c>) and the Blender manual's basic.human reference:
    /// the spine chain is <c>spine→spine.001..spine.006</c> where <c>spine</c> IS the
    /// pelvis/hips bone (it sits at the pelvis and parents the thighs), spine.001–003 are
    /// the torso, spine.004/005 the two neck bones (004 carries <see cref="BoneRole.Neck"/>,
    /// 005 stays unmapped — same policy as ActorCore's NeckTwist02) and spine.006 is the
    /// head. Limbs: <c>shoulder.L→upper_arm.L→forearm.L→hand.L</c>,
    /// <c>thigh.L→shin.L→foot.L→toe.L</c>; fingers <c>thumb.01.L..03.L</c> and
    /// <c>f_index/f_middle/f_ring/f_pinky.01.L..03.L</c>. The <c>^DEF-</c> namespace
    /// pattern also matches rigify's generated deform skeleton (<c>DEF-spine.001</c>,
    /// <c>DEF-upper_arm.L</c>, …); the segmented deform twins (<c>DEF-upper_arm.L.001</c>),
    /// <c>palm.*</c>, <c>pelvis.L/R</c>, <c>heel.02.L</c>, face bones and the generated
    /// ORG-/MCH-/control bones have no aliases and are never mapped.
    /// </summary>
    public static Profile Rigify { get; } = BuildRigify();

    /// <summary>
    /// VRoid Studio / VRM avatars (UniVRM exports): <c>J_Bip_&lt;side&gt;_&lt;Part&gt;</c>
    /// bones where side is <c>C</c> (center), <c>L</c> or <c>R</c> — the standard VRoid
    /// skeleton behind the VRM humanoid spec (vrm-c/vrm-specification, humanoid bone map):
    /// <c>J_Bip_C_Hips/Spine/Chest/UpperChest/Neck/Head</c>,
    /// <c>J_Bip_L_Shoulder→UpperArm→LowerArm→Hand</c>,
    /// <c>J_Bip_L_UpperLeg→LowerLeg→Foot→ToeBase</c>, fingers
    /// <c>J_Bip_L_Thumb1..3/Index1..3/Middle1..3/Ring1..3/Little1..3</c> ("Little" is the
    /// pinky, per the VRM littleProximal/Intermediate/Distal humanoid bones). Secondary
    /// physics/adjust bones (<c>J_Sec_*</c>, <c>J_Adj_*</c>) and the <c>Root</c> bone have
    /// no aliases and are never mapped.
    /// </summary>
    public static Profile Vrm { get; } = BuildVrm();

    /// <summary>
    /// Blender Auto-Rig Pro humanoid FBX exports — bone names verified empirically against
    /// the local user repro <c>dev/corpus/todo/Defenses.fbx</c> (the PunchPerfect family):
    /// <c>.x</c> suffix marks center bones, <c>.l/.r</c> the sides, and the exported limb
    /// deform bones carry the <c>_stretch</c> twin name — <c>root.x</c> is the hips
    /// (under a ground bone <c>root</c>), <c>spine_01.x→spine_02.x→spine_03.x</c>,
    /// <c>neck.x</c>, <c>head.x</c>, arms <c>shoulder.l→arm_stretch.l→forearm_stretch.l→
    /// hand.l</c> (plain "arm", NOT "upperarm"), legs <c>thigh_stretch.l→leg_stretch.l→
    /// foot.l→toes_01.l</c> ("leg" is the calf). Fingers keep Auto-Rig Pro's <c>c_</c>
    /// control prefix on the exported deform chain: <c>c_thumb1.l..3.l</c>,
    /// <c>c_index/c_middle/c_ring/c_pinky1.l..3.l</c>. Leftover finger-tip markers
    /// (<c>mixamorig:LeftHandIndex4</c> in the repro) and <c>root</c> have no aliases.
    /// </summary>
    public static Profile AutoRigPro { get; } = BuildAutoRigPro();

    /// <summary>All built-in presets, in detection order (first wins score ties — see
    /// <see cref="SmplX"/> vs <see cref="Smpl"/>).</summary>
    public static IReadOnlyList<Profile> All { get; } =
        new[]
        {
            Mixamo, ActorCoreCc, UeMannequin, RokokoBvh, SmplX, Smpl, SomaBvh, ClassicBvh,
            Biped, DazPoser, Rigify, Vrm, AutoRigPro,
        };

    // ---------------------------------------------------------------- mixamo

    private static Profile BuildMixamo()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "Hips" },
            [BoneRole.Spine0] = new[] { "Spine" },
            [BoneRole.Spine1] = new[] { "Spine1" },
            [BoneRole.Spine2] = new[] { "Spine2" },
            [BoneRole.Neck] = new[] { "Neck" },
            [BoneRole.Head] = new[] { "Head" },
        };
        foreach (var (roleSide, nameSide) in Sides())
        {
            aliases[Role("Clavicle", roleSide)] = new[] { $"{nameSide}Shoulder" };
            aliases[Role("UpperArm", roleSide)] = new[] { $"{nameSide}Arm" };
            aliases[Role("LowerArm", roleSide)] = new[] { $"{nameSide}ForeArm" };
            aliases[Role("Hand", roleSide)] = new[] { $"{nameSide}Hand" };
            aliases[Role("UpperLeg", roleSide)] = new[] { $"{nameSide}UpLeg" };
            aliases[Role("LowerLeg", roleSide)] = new[] { $"{nameSide}Leg" };
            aliases[Role("Foot", roleSide)] = new[] { $"{nameSide}Foot" };
            aliases[Role("Toe", roleSide)] = new[] { $"{nameSide}ToeBase" };

            foreach (var finger in new[] { "Thumb", "Index", "Middle", "Ring", "Pinky" })
            {
                aliases[Role($"{finger}Prox", roleSide)] = new[] { $"{nameSide}Hand{finger}1" };
                aliases[Role($"{finger}Mid", roleSide)] = new[] { $"{nameSide}Hand{finger}2" };
                aliases[Role($"{finger}Dist", roleSide)] = new[] { $"{nameSide}Hand{finger}3" };
            }
        }
        // Both ':' (FBX namespace) and '_' (namespace mangled by some exporters) forms occur
        // in the wild; some Mixamo downloads ship with no namespace at all, which still
        // matches because the aliases are the bare names.
        return new Profile("mixamo", new[] { "^mixamorig[0-9]*:", "^mixamorig[0-9]*_" }, aliases);
    }

    // ---------------------------------------------------------------- actorcore / cc

    private static Profile BuildActorCoreCc()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "Hip" },
            [BoneRole.Spine0] = new[] { "Waist" },
            [BoneRole.Spine1] = new[] { "Spine01" },
            [BoneRole.Spine2] = new[] { "Spine02" },
            [BoneRole.Neck] = new[] { "NeckTwist01" },
            [BoneRole.Head] = new[] { "Head" },
        };
        foreach (var roleSide in new[] { "L", "R" })
        {
            var nameSide = roleSide; // CC bones use the bare side letter: CC_Base_L_Thigh.
            aliases[Role("Clavicle", roleSide)] = new[] { $"{nameSide}_Clavicle" };
            aliases[Role("UpperArm", roleSide)] = new[] { $"{nameSide}_Upperarm" };
            aliases[Role("LowerArm", roleSide)] = new[] { $"{nameSide}_Forearm" };
            aliases[Role("Hand", roleSide)] = new[] { $"{nameSide}_Hand" };
            aliases[Role("UpperLeg", roleSide)] = new[] { $"{nameSide}_Thigh" };
            aliases[Role("LowerLeg", roleSide)] = new[] { $"{nameSide}_Calf" };
            aliases[Role("Foot", roleSide)] = new[] { $"{nameSide}_Foot" };
            aliases[Role("Toe", roleSide)] = new[] { $"{nameSide}_ToeBase" };

            foreach (var (role, cc) in new[]
            {
                ("Thumb", "Thumb"), ("Index", "Index"), ("Middle", "Mid"), ("Ring", "Ring"), ("Pinky", "Pinky"),
            })
            {
                aliases[Role($"{role}Prox", roleSide)] = new[] { $"{nameSide}_{cc}1" };
                aliases[Role($"{role}Mid", roleSide)] = new[] { $"{nameSide}_{cc}2" };
                aliases[Role($"{role}Dist", roleSide)] = new[] { $"{nameSide}_{cc}3" };
            }
        }
        return new Profile("actorcore_cc", new[] { "^CC_Base_" }, aliases);
    }

    // ---------------------------------------------------------------- ue mannequin

    private static Profile BuildUeMannequin()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "pelvis" },
            [BoneRole.Spine0] = new[] { "spine_01" },
            [BoneRole.Spine1] = new[] { "spine_02" },
            [BoneRole.Spine2] = new[] { "spine_03" },
            [BoneRole.Spine3] = new[] { "spine_04" },
            [BoneRole.Spine4] = new[] { "spine_05" },
            [BoneRole.Neck] = new[] { "neck_01" },
            [BoneRole.Head] = new[] { "head" },
        };
        foreach (var (roleSide, s) in new[] { ("L", "l"), ("R", "r") })
        {
            aliases[Role("Clavicle", roleSide)] = new[] { $"clavicle_{s}" };
            aliases[Role("UpperArm", roleSide)] = new[] { $"upperarm_{s}" };
            aliases[Role("LowerArm", roleSide)] = new[] { $"lowerarm_{s}" };
            aliases[Role("Hand", roleSide)] = new[] { $"hand_{s}" };
            aliases[Role("UpperLeg", roleSide)] = new[] { $"thigh_{s}" };
            aliases[Role("LowerLeg", roleSide)] = new[] { $"calf_{s}" };
            aliases[Role("Foot", roleSide)] = new[] { $"foot_{s}" };
            aliases[Role("Toe", roleSide)] = new[] { $"ball_{s}" };

            foreach (var (role, ue) in new[]
            {
                ("Thumb", "thumb"), ("Index", "index"), ("Middle", "middle"), ("Ring", "ring"), ("Pinky", "pinky"),
            })
            {
                // UE5 mannequin adds metacarpals for the four fingers (not the thumb).
                if (role != "Thumb")
                    aliases[Role($"{role}Meta", roleSide)] = new[] { $"{ue}_metacarpal_{s}" };
                aliases[Role($"{role}Prox", roleSide)] = new[] { $"{ue}_01_{s}" };
                aliases[Role($"{role}Mid", roleSide)] = new[] { $"{ue}_02_{s}" };
                aliases[Role($"{role}Dist", roleSide)] = new[] { $"{ue}_03_{s}" };
            }
        }
        return new Profile("ue_mannequin", new string[0], aliases);
    }

    // ---------------------------------------------------------------- rokoko / xsens bvh

    private static Profile BuildRokokoBvh()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "Hips" },
            // Spine naming varies (Spine, Spine1..Spine4); ordered alias preference plus the
            // used-bone exclusion in the detector shifts the chain up when "Spine" is absent.
            [BoneRole.Spine0] = new[] { "Spine", "Spine1" },
            [BoneRole.Spine1] = new[] { "Spine1", "Spine2" },
            [BoneRole.Spine2] = new[] { "Spine2", "Spine3" },
            [BoneRole.Spine3] = new[] { "Spine3", "Spine4" },
            [BoneRole.Spine4] = new[] { "Spine4" },
            [BoneRole.Neck] = new[] { "Neck", "Neck1" },
            [BoneRole.Head] = new[] { "Head" },
        };
        foreach (var (roleSide, nameSide) in Sides())
        {
            aliases[Role("Clavicle", roleSide)] = new[] { $"{nameSide}Shoulder", $"{nameSide}Collar" };
            aliases[Role("UpperArm", roleSide)] = new[] { $"{nameSide}Arm", $"{nameSide}UpperArm" };
            aliases[Role("LowerArm", roleSide)] = new[] { $"{nameSide}ForeArm", $"{nameSide}LowerArm" };
            aliases[Role("Hand", roleSide)] = new[] { $"{nameSide}Hand" };
            aliases[Role("UpperLeg", roleSide)] = new[] { $"{nameSide}UpLeg", $"{nameSide}Thigh", $"{nameSide}UpperLeg" };
            aliases[Role("LowerLeg", roleSide)] = new[] { $"{nameSide}Leg", $"{nameSide}Shin", $"{nameSide}LowerLeg" };
            aliases[Role("Foot", roleSide)] = new[] { $"{nameSide}Foot" };
            aliases[Role("Toe", roleSide)] = new[] { $"{nameSide}Toe", $"{nameSide}ToeBase" };
        }
        return new Profile("rokoko_bvh", new string[0], aliases);
    }

    // ---------------------------------------------------------------- smpl / smpl-x

    private static Profile BuildSmpl(bool withFingers)
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "Pelvis" },
            [BoneRole.Spine0] = new[] { "Spine1" },
            [BoneRole.Spine1] = new[] { "Spine2" },
            [BoneRole.Spine2] = new[] { "Spine3" },
            [BoneRole.Neck] = new[] { "Neck" },
            [BoneRole.Head] = new[] { "Head" },
        };
        foreach (var (roleSide, abbr, word) in new[] { ("L", "L", "left"), ("R", "R", "right") })
        {
            // Both documented spellings per role: abbreviated FBX-rig names ("L_Hip") and
            // spelled model joint names ("left_hip"). Comparison is separator-insensitive.
            aliases[Role("Clavicle", roleSide)] = new[] { $"{abbr}_Collar", $"{word}_collar" };
            aliases[Role("UpperArm", roleSide)] = new[] { $"{abbr}_Shoulder", $"{word}_shoulder" };
            aliases[Role("LowerArm", roleSide)] = new[] { $"{abbr}_Elbow", $"{word}_elbow" };
            aliases[Role("Hand", roleSide)] = new[] { $"{abbr}_Wrist", $"{word}_wrist" };
            aliases[Role("UpperLeg", roleSide)] = new[] { $"{abbr}_Hip", $"{word}_hip" };
            aliases[Role("LowerLeg", roleSide)] = new[] { $"{abbr}_Knee", $"{word}_knee" };
            aliases[Role("Foot", roleSide)] = new[] { $"{abbr}_Ankle", $"{word}_ankle" };
            aliases[Role("Toe", roleSide)] = new[] { $"{abbr}_Foot", $"{word}_foot" };

            if (!withFingers)
                continue;

            // SMPL-X finger joints (left_index1..3 etc., per vchoutas/smplx joint_names.py).
            foreach (var finger in new[] { "thumb", "index", "middle", "ring", "pinky" })
            {
                var name = char.ToUpperInvariant(finger[0]) + finger[1..];
                aliases[Role($"{name}Prox", roleSide)] = new[] { $"{word}_{finger}1" };
                aliases[Role($"{name}Mid", roleSide)] = new[] { $"{word}_{finger}2" };
                aliases[Role($"{name}Dist", roleSide)] = new[] { $"{word}_{finger}3" };
            }
        }
        // Gendered SMPL FBX rigs prefix every bone (m_avg_L_Hip, f_avg_Pelvis).
        return new Profile(withFingers ? "smpl_x" : "smpl", new[] { "^m_avg_", "^f_avg_" }, aliases);
    }

    // ---------------------------------------------------------------- nvidia soma bvh

    private static Profile BuildSomaBvh()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "Hips" },
            [BoneRole.Spine0] = new[] { "Spine1" },
            [BoneRole.Spine1] = new[] { "Spine2" },
            [BoneRole.Spine2] = new[] { "Chest" },
            [BoneRole.Neck] = new[] { "Neck1" },
            [BoneRole.Head] = new[] { "Head" },
        };
        foreach (var (roleSide, nameSide) in Sides())
        {
            aliases[Role("Clavicle", roleSide)] = new[] { $"{nameSide}Shoulder" };
            aliases[Role("UpperArm", roleSide)] = new[] { $"{nameSide}Arm" };
            aliases[Role("LowerArm", roleSide)] = new[] { $"{nameSide}ForeArm" };
            aliases[Role("Hand", roleSide)] = new[] { $"{nameSide}Hand" };
            // SOMA's "Leg" is the thigh, "Shin" the calf — the decisive difference from
            // mixamo, where "Leg" is the calf under "UpLeg".
            aliases[Role("UpperLeg", roleSide)] = new[] { $"{nameSide}Leg" };
            aliases[Role("LowerLeg", roleSide)] = new[] { $"{nameSide}Shin" };
            aliases[Role("Foot", roleSide)] = new[] { $"{nameSide}Foot" };
            aliases[Role("Toe", roleSide)] = new[] { $"{nameSide}ToeBase" };

            // Mixamo-style finger names; segment 4 ("LeftHandIndex4") and the *End markers
            // carry no role.
            foreach (var finger in new[] { "Thumb", "Index", "Middle", "Ring", "Pinky" })
            {
                aliases[Role($"{finger}Prox", roleSide)] = new[] { $"{nameSide}Hand{finger}1" };
                aliases[Role($"{finger}Mid", roleSide)] = new[] { $"{nameSide}Hand{finger}2" };
                aliases[Role($"{finger}Dist", roleSide)] = new[] { $"{nameSide}Hand{finger}3" };
            }
        }
        return new Profile("soma_bvh", new string[0], aliases);
    }

    // ---------------------------------------------------------------- classic bvh

    private static Profile BuildClassicBvh()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "Hips" },
            [BoneRole.Spine0] = new[] { "Chest" },
            [BoneRole.Spine1] = new[] { "Chest2" },
            [BoneRole.Spine2] = new[] { "Chest3" },
            [BoneRole.Spine3] = new[] { "Chest4" },
            [BoneRole.Neck] = new[] { "Neck" },
            [BoneRole.Head] = new[] { "Head" },
        };
        foreach (var (roleSide, nameSide) in Sides())
        {
            aliases[Role("Clavicle", roleSide)] = new[] { $"{nameSide}Collar" };
            aliases[Role("UpperArm", roleSide)] = new[] { $"{nameSide}Shoulder" };
            aliases[Role("LowerArm", roleSide)] = new[] { $"{nameSide}Elbow" };
            aliases[Role("Hand", roleSide)] = new[] { $"{nameSide}Wrist" };
            aliases[Role("UpperLeg", roleSide)] = new[] { $"{nameSide}Hip" };
            aliases[Role("LowerLeg", roleSide)] = new[] { $"{nameSide}Knee" };
            aliases[Role("Foot", roleSide)] = new[] { $"{nameSide}Ankle" };
            aliases[Role("Toe", roleSide)] = new[] { $"{nameSide}Toe" };
        }
        return new Profile("classic_bvh", new string[0], aliases);
    }

    // ---------------------------------------------------------------- 3ds max biped

    private static Profile BuildBiped()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "Pelvis" },
            [BoneRole.Spine0] = new[] { "Spine" },
            [BoneRole.Spine1] = new[] { "Spine1" },
            [BoneRole.Spine2] = new[] { "Spine2" },
            [BoneRole.Spine3] = new[] { "Spine3" },
            [BoneRole.Neck] = new[] { "Neck" },
            [BoneRole.Head] = new[] { "Head" },
        };
        foreach (var s in new[] { "L", "R" })
        {
            aliases[Role("Clavicle", s)] = new[] { $"{s} Clavicle" };
            aliases[Role("UpperArm", s)] = new[] { $"{s} UpperArm" };
            aliases[Role("LowerArm", s)] = new[] { $"{s} Forearm" };
            aliases[Role("Hand", s)] = new[] { $"{s} Hand" };
            aliases[Role("UpperLeg", s)] = new[] { $"{s} Thigh" };
            aliases[Role("LowerLeg", s)] = new[] { $"{s} Calf" };
            aliases[Role("Foot", s)] = new[] { $"{s} Foot" };
            aliases[Role("Toe", s)] = new[] { $"{s} Toe0" };

            // Numbered finger chains: Finger0 is the thumb; segment names append the
            // phalanx digit (Finger0 → Finger01 → Finger02, Finger1 → Finger11 → ...).
            foreach (var (finger, n) in new[]
            {
                ("Thumb", 0), ("Index", 1), ("Middle", 2), ("Ring", 3), ("Pinky", 4),
            })
            {
                aliases[Role($"{finger}Prox", s)] = new[] { $"{s} Finger{n}" };
                aliases[Role($"{finger}Mid", s)] = new[] { $"{s} Finger{n}1" };
                aliases[Role($"{finger}Dist", s)] = new[] { $"{s} Finger{n}2" };
            }
        }
        // "Bip01 "/"Bip001 " biped-name prefix; underscore form covers exporters that
        // mangle the spaces ("Bip01_L_Thigh"). The bare COM root "Bip01" is untouched by
        // the pattern (no trailing separator) and has no alias.
        return new Profile("biped", new[] { @"^Bip\d+[ _]" }, aliases);
    }

    // ---------------------------------------------------------------- daz / poser

    private static Profile BuildDazPoser()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "hip" },
            [BoneRole.Spine0] = new[] { "abdomen" },
            // Poser classic / DAZ Gen4 spine is abdomen→chest; DAZ Genesis 1/2 inserts
            // abdomen2. Ordered preference + used-bone exclusion handles both: without
            // abdomen2 the chest falls back to Spine1 and Spine2 stays unmapped.
            [BoneRole.Spine1] = new[] { "abdomen2", "chest" },
            [BoneRole.Spine2] = new[] { "chest" },
            [BoneRole.Neck] = new[] { "neck" },
            [BoneRole.Head] = new[] { "head" },
        };
        foreach (var s in new[] { "L", "R" })
        {
            var p = s == "L" ? "l" : "r"; // lower-case side prefix: lShldr, rThigh
            aliases[Role("Clavicle", s)] = new[] { $"{p}Collar" };
            aliases[Role("UpperArm", s)] = new[] { $"{p}Shldr" };
            aliases[Role("LowerArm", s)] = new[] { $"{p}ForeArm" };
            aliases[Role("Hand", s)] = new[] { $"{p}Hand" };
            aliases[Role("UpperLeg", s)] = new[] { $"{p}Thigh" };
            aliases[Role("LowerLeg", s)] = new[] { $"{p}Shin" };
            aliases[Role("Foot", s)] = new[] { $"{p}Foot" };
            aliases[Role("Toe", s)] = new[] { $"{p}Toe" };

            foreach (var (role, daz) in new[]
            {
                ("Thumb", "Thumb"), ("Index", "Index"), ("Middle", "Mid"), ("Ring", "Ring"), ("Pinky", "Pinky"),
            })
            {
                aliases[Role($"{role}Prox", s)] = new[] { $"{p}{daz}1" };
                aliases[Role($"{role}Mid", s)] = new[] { $"{p}{daz}2" };
                aliases[Role($"{role}Dist", s)] = new[] { $"{p}{daz}3" };
            }
        }
        return new Profile("daz_poser", new string[0], aliases);
    }

    // ---------------------------------------------------------------- blender rigify

    private static Profile BuildRigify()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            // rigify's "spine" bone sits AT the pelvis and parents both thighs — it is
            // the hips, not a spine link (rigify/metarigs/human.py).
            [BoneRole.Hips] = new[] { "spine" },
            [BoneRole.Spine0] = new[] { "spine.001" },
            [BoneRole.Spine1] = new[] { "spine.002" },
            [BoneRole.Spine2] = new[] { "spine.003" },
            // spine.004 + spine.005 are the two neck bones, spine.006 the head;
            // spine.005 stays unmapped (same policy as ActorCore's NeckTwist02).
            [BoneRole.Neck] = new[] { "spine.004" },
            [BoneRole.Head] = new[] { "spine.006" },
        };
        foreach (var s in new[] { "L", "R" })
        {
            aliases[Role("Clavicle", s)] = new[] { $"shoulder.{s}" };
            aliases[Role("UpperArm", s)] = new[] { $"upper_arm.{s}" };
            aliases[Role("LowerArm", s)] = new[] { $"forearm.{s}" };
            aliases[Role("Hand", s)] = new[] { $"hand.{s}" };
            aliases[Role("UpperLeg", s)] = new[] { $"thigh.{s}" };
            aliases[Role("LowerLeg", s)] = new[] { $"shin.{s}" };
            aliases[Role("Foot", s)] = new[] { $"foot.{s}" };
            aliases[Role("Toe", s)] = new[] { $"toe.{s}" };

            foreach (var (role, rigify) in new[]
            {
                ("Thumb", "thumb"), ("Index", "f_index"), ("Middle", "f_middle"),
                ("Ring", "f_ring"), ("Pinky", "f_pinky"),
            })
            {
                aliases[Role($"{role}Prox", s)] = new[] { $"{rigify}.01.{s}" };
                aliases[Role($"{role}Mid", s)] = new[] { $"{rigify}.02.{s}" };
                aliases[Role($"{role}Dist", s)] = new[] { $"{rigify}.03.{s}" };
            }
        }
        // The generated deform skeleton prefixes every deform bone with "DEF-"; its
        // segmented limb twins ("DEF-upper_arm.L.001") keep their numeric suffix after
        // stripping and therefore never collide with the whole-bone aliases.
        return new Profile("rigify", new[] { "^DEF-" }, aliases);
    }

    // ---------------------------------------------------------------- vroid / vrm

    private static Profile BuildVrm()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "J_Bip_C_Hips" },
            [BoneRole.Spine0] = new[] { "J_Bip_C_Spine" },
            [BoneRole.Spine1] = new[] { "J_Bip_C_Chest" },
            [BoneRole.Spine2] = new[] { "J_Bip_C_UpperChest" },
            [BoneRole.Neck] = new[] { "J_Bip_C_Neck" },
            [BoneRole.Head] = new[] { "J_Bip_C_Head" },
        };
        foreach (var s in new[] { "L", "R" })
        {
            aliases[Role("Clavicle", s)] = new[] { $"J_Bip_{s}_Shoulder" };
            aliases[Role("UpperArm", s)] = new[] { $"J_Bip_{s}_UpperArm" };
            aliases[Role("LowerArm", s)] = new[] { $"J_Bip_{s}_LowerArm" };
            aliases[Role("Hand", s)] = new[] { $"J_Bip_{s}_Hand" };
            aliases[Role("UpperLeg", s)] = new[] { $"J_Bip_{s}_UpperLeg" };
            aliases[Role("LowerLeg", s)] = new[] { $"J_Bip_{s}_LowerLeg" };
            aliases[Role("Foot", s)] = new[] { $"J_Bip_{s}_Foot" };
            aliases[Role("Toe", s)] = new[] { $"J_Bip_{s}_ToeBase" };

            foreach (var (role, vrm) in new[]
            {
                ("Thumb", "Thumb"), ("Index", "Index"), ("Middle", "Middle"),
                ("Ring", "Ring"), ("Pinky", "Little"),
            })
            {
                aliases[Role($"{role}Prox", s)] = new[] { $"J_Bip_{s}_{vrm}1" };
                aliases[Role($"{role}Mid", s)] = new[] { $"J_Bip_{s}_{vrm}2" };
                aliases[Role($"{role}Dist", s)] = new[] { $"J_Bip_{s}_{vrm}3" };
            }
        }
        return new Profile("vrm", new string[0], aliases);
    }

    // ---------------------------------------------------------------- auto-rig pro

    private static Profile BuildAutoRigPro()
    {
        var aliases = new Dictionary<BoneRole, string[]>
        {
            [BoneRole.Hips] = new[] { "root.x" },
            [BoneRole.Spine0] = new[] { "spine_01.x" },
            [BoneRole.Spine1] = new[] { "spine_02.x" },
            [BoneRole.Spine2] = new[] { "spine_03.x" },
            [BoneRole.Neck] = new[] { "neck.x" },
            [BoneRole.Head] = new[] { "head.x" },
        };
        foreach (var s in new[] { "L", "R" })
        {
            var p = s == "L" ? "l" : "r";
            aliases[Role("Clavicle", s)] = new[] { $"shoulder.{p}" };
            aliases[Role("UpperArm", s)] = new[] { $"arm_stretch.{p}" };
            aliases[Role("LowerArm", s)] = new[] { $"forearm_stretch.{p}" };
            aliases[Role("Hand", s)] = new[] { $"hand.{p}" };
            aliases[Role("UpperLeg", s)] = new[] { $"thigh_stretch.{p}" };
            aliases[Role("LowerLeg", s)] = new[] { $"leg_stretch.{p}" };
            aliases[Role("Foot", s)] = new[] { $"foot.{p}" };
            aliases[Role("Toe", s)] = new[] { $"toes_01.{p}" };

            // Exported finger deform bones keep ARP's c_ control prefix (Defenses.fbx).
            foreach (var finger in new[] { "thumb", "index", "middle", "ring", "pinky" })
            {
                var role = char.ToUpperInvariant(finger[0]) + finger[1..];
                aliases[Role($"{role}Prox", s)] = new[] { $"c_{finger}1.{p}" };
                aliases[Role($"{role}Mid", s)] = new[] { $"c_{finger}2.{p}" };
                aliases[Role($"{role}Dist", s)] = new[] { $"c_{finger}3.{p}" };
            }
        }
        return new Profile("auto_rig_pro", new string[0], aliases);
    }

    // ---------------------------------------------------------------- helpers

    private static IEnumerable<(string RoleSide, string NameSide)> Sides()
    {
        yield return ("L", "Left");
        yield return ("R", "Right");
    }

    private static BoneRole Role(string baseName, string side)
        => System.Enum.Parse<BoneRole>(baseName + side);
}