using System.Collections.Generic;
using UnityEngine;
namespace UniVRM10
{
///
/// XR_EXT_hand_tracking の joint を VRM-1.0 の TPose に当てはめたときの方向を定義します。
///
/// * https://registry.khronos.org/OpenXR/specs/1.0/html/xrspec.html#_conventions_of_hand_joints
/// * https://github.com/vrm-c/vrm-specification/blob/master/specification/VRMC_vrm-1.0/tpose.ja.md
///
/// OpenXR は右手系なのに対して Unityは左手系です。
/// この Rig が期待するボーンの値は、XR_EXT_hand_tracking の Joint の値を Z軸反転で座標変換したものです。
///
public static class XR_EXT_hand_tracking
{
///
/// up vector と forward vector の外積により空間を算出して、回転を得ます。
///
///
///
///
public static Quaternion GetRotation(Vector3 up, Vector3 forward)
{
var xAxis = Vector3.Cross(up, forward).normalized;
var m = new Matrix4x4(xAxis, up, forward, new Vector4(0, 0, 0, 1));
return m.rotation;
}
public static Quaternion LeftHand = GetRotation(Vector3.up, Vector3.left);
public static Quaternion RightHand = GetRotation(Vector3.up, Vector3.right);
///
/// 親指は XZ 平面45度です。
///
public static Quaternion LeftThumb = GetRotation((Vector3.forward + Vector3.right).normalized, (Vector3.left + Vector3.forward).normalized);
///
/// 親指は XZ 平面45度です。
///
public static Quaternion RightThumb = GetRotation((Vector3.forward + Vector3.left).normalized, (Vector3.right + Vector3.forward).normalized);
///
/// VRM-1.0 の T-Pose の定義から各指はX軸と並行です。親指はXZ平面に45度です。
///
public static IReadOnlyDictionary InitialRotations => new Dictionary()
{
// Left
{HumanBodyBones.LeftHand, LeftHand},
{HumanBodyBones.LeftThumbProximal, LeftThumb},
{HumanBodyBones.LeftThumbIntermediate, LeftThumb},
{HumanBodyBones.LeftThumbDistal, LeftThumb},
{HumanBodyBones.LeftIndexProximal, LeftHand},
{HumanBodyBones.LeftIndexIntermediate, LeftHand},
{HumanBodyBones.LeftIndexDistal, LeftHand},
{HumanBodyBones.LeftMiddleProximal, LeftHand},
{HumanBodyBones.LeftMiddleIntermediate, LeftHand},
{HumanBodyBones.LeftMiddleDistal, LeftHand},
{HumanBodyBones.LeftRingProximal, LeftHand},
{HumanBodyBones.LeftRingIntermediate, LeftHand},
{HumanBodyBones.LeftRingDistal, LeftHand},
{HumanBodyBones.LeftLittleProximal, LeftHand},
{HumanBodyBones.LeftLittleIntermediate, LeftHand},
{HumanBodyBones.LeftLittleDistal, LeftHand},
// Right
{HumanBodyBones.RightHand, RightHand},
{HumanBodyBones.RightThumbProximal, RightThumb},
{HumanBodyBones.RightThumbIntermediate, RightThumb},
{HumanBodyBones.RightThumbDistal, RightThumb},
{HumanBodyBones.RightIndexProximal, RightHand},
{HumanBodyBones.RightIndexIntermediate, RightHand},
{HumanBodyBones.RightIndexDistal, RightHand},
{HumanBodyBones.RightMiddleProximal, RightHand},
{HumanBodyBones.RightMiddleIntermediate, RightHand},
{HumanBodyBones.RightMiddleDistal, RightHand},
{HumanBodyBones.RightRingProximal, RightHand},
{HumanBodyBones.RightRingIntermediate, RightHand},
{HumanBodyBones.RightRingDistal, RightHand},
{HumanBodyBones.RightLittleProximal, RightHand},
{HumanBodyBones.RightLittleIntermediate, RightHand},
{HumanBodyBones.RightLittleDistal, RightHand},
};
}
}