Unity : How to Limit springbone movement when moving character at fast speed ?

[Pk-c]

Hello

I have imported a vroid character in unity, the spingbones works well, but after I implemented run, I notice the movement or hair / skirt / chest is very glitchy because my character is running fast.

I tried to change parameters like stiffnessForce / drag but it didn't help much.

What can I do to prevent this ?

I tried to modify the code a bit to add a hard limit, it kinda works but I'm not sure it is a good way to do it

// verlet積分で次の位置を計算
                var dampingFactor = 1.0f - joint.dragForce; // Normal damping factor based on drag
                var external = (joint.gravityDir * joint.gravityPower + spring.ExternalData->ExternalForce) * DeltaTime;

                // Introduce a speed limit to reduce instability at high speeds
                var maxSpeed = 2.0f;
                var movement = (currentTail - prevTail) * dampingFactor;
                if (movement.magnitude > maxSpeed * DeltaTime)
                {
                    movement = movement.normalized * maxSpeed * DeltaTime;
                }

                // Calculate next position of the tail
                var nextTail = currentTail
                               + movement // Continue movement from the previous frame with potential speed limit
                               + parentRotation * logic.localRotation * logic.boneAxis * joint.stiffnessForce * DeltaTime // Parent-induced motion
                               + external; // External forces

                // Normalize to maintain the bone length
                nextTail = headTransform.position + (nextTail - headTransform.position).normalized * logic.length;


                //Original code :

                /*// verlet積分で次の位置を計算
                var external = (joint.gravityDir * joint.gravityPower + spring.ExternalData->ExternalForce) * DeltaTime;
                var nextTail = currentTail
                               + (currentTail - prevTail) * (1.0f - joint.dragForce) // 前フレームの移動を継続する(減衰もあるよ)
                               + parentRotation * logic.localRotation * logic.boneAxis *
                               joint.stiffnessForce * DeltaTime // 親の回転による子ボーンの移動目標
                               + external; // 外力による移動量

                // 長さをboneLengthに強制
                nextTail = headTransform.position + (nextTail - headTransform.position).normalized * logic.length;*/`

[ToffelsKater]

Hey sorry i'm using unreal and dont know unity but we can set the spring bone parameters in real-time by using this function "Set Vrm Spring bone param"
It is in the Animation instance maybe you have something similar?

[ToffelsKater]

But before trying to look for an issue in the game engine i would suggest adjusting the parameters in your avatar directly in blender