From b8ae94ddea3b0282f0a2ac5b6b096e22a5d419b6 Mon Sep 17 00:00:00 2001
From: amamagi <amausagiii@gmail.com>
Date: Mon, 27 Jun 2022 13:26:36 +0900
Subject: [PATCH] use cached local rotation for spring bone calculation

---
 .../Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs  | 12 +++++++++++-
 .../InputPorts/FastSpringBoneBuffer.cs               |  2 +-
 .../FastSpringBone/InputPorts/FastSpringBoneJoint.cs |  1 +
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs b/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs
index 07adca4d6..7c1d11a61 100644
--- a/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs
+++ b/Assets/VRM10/Runtime/Components/Vrm10Runtime/Vrm10Runtime.cs
@@ -112,11 +112,21 @@ namespace UniVRM10
                             gravityDir = joint.m_gravityDir,
                             gravityPower = joint.m_gravityPower,
                             stiffnessForce = joint.m_stiffnessForce
-                        }
+                        },
+                        DefaultLocalRotation = GetOrAddDefaultTransformState(joint.transform).rotation
                     }).ToArray(),
                 }).ToArray());
         }
 
+        private (Vector3 position, Quaternion rotation) GetOrAddDefaultTransformState(Transform tf)
+        {
+            if (m_defaultTransformStates.TryGetValue(tf, out var defaultTransformState))
+            {
+                return defaultTransformState;
+            }
+            return m_defaultTransformStates[tf] = (tf.position, tf.rotation);
+        }
+
         private static BlittableColliderType TranslateColliderType(VRM10SpringBoneColliderTypes colliderType)
         {
             switch (colliderType)
diff --git a/Assets/VRM10/Runtime/FastSpringBone/InputPorts/FastSpringBoneBuffer.cs b/Assets/VRM10/Runtime/FastSpringBone/InputPorts/FastSpringBoneBuffer.cs
index 84186af62..89df4753b 100644
--- a/Assets/VRM10/Runtime/FastSpringBone/InputPorts/FastSpringBoneBuffer.cs
+++ b/Assets/VRM10/Runtime/FastSpringBone/InputPorts/FastSpringBoneBuffer.cs
@@ -108,7 +108,7 @@ namespace UniVRM10.FastSpringBones.System
                         parentTransformIndex = parent != null ? transformIndexDictionary[parent] : -1,
                         currentTail = currentTail,
                         prevTail = currentTail,
-                        localRotation = joint.Transform.localRotation,
+                        localRotation = joint.DefaultLocalRotation,
                         boneAxis = localChildPosition.normalized,
                         length = localChildPosition.magnitude
                     });
diff --git a/Assets/VRM10/Runtime/FastSpringBone/InputPorts/FastSpringBoneJoint.cs b/Assets/VRM10/Runtime/FastSpringBone/InputPorts/FastSpringBoneJoint.cs
index 7aff7cf71..98d1a8e65 100644
--- a/Assets/VRM10/Runtime/FastSpringBone/InputPorts/FastSpringBoneJoint.cs
+++ b/Assets/VRM10/Runtime/FastSpringBone/InputPorts/FastSpringBoneJoint.cs
@@ -9,5 +9,6 @@ namespace UniVRM10.FastSpringBones.System
     {
         public Transform Transform;
         public BlittableJoint Joint;
+        public Quaternion DefaultLocalRotation;
     }
 }
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