设备工作区转换教程

本教程是对 基础力反馈教程 通过演示如何调整设备的位移、旋转和缩放 Inverse3 借助其空间变换的属性和方法。

导言

在配置了基础力反馈场景后，您可能会发现对“力反馈原点” 或“力反馈控制器”所做的调整（例如平移、缩放或旋转）并未如预期般影响力反馈效果。 力反馈始终对应于设备前方的一个不可见球体，而该球体不受这些变换的影响。

这种偏差的原因在于，力计算使用的是设备光标的实际坐标（未经变换）。 为解决此问题，我们将使用Inverse3 Controller组件提供的、已缓存且对线程安全的变换矩阵，从而能够对力反馈计算应用世界空间变换。

场景设置

请从“基础力反馈”教程场景开始，并确保Inverse3 Controller的左右方向与您的设备一致。 将Haptic Controller旋转至Haply 标志朝向摄像头的方向，然后根据需要调整Haptic Origin的缩放比例，以扩大光标范围或更改其位置。

反作用力脚本的修改

复制该脚本 SphereForceFeedback.cs 参考基础力反馈教程，并在回调函数中进行以下修改 OnDeviceStateChanged :

• 替换 device.CursorLocalPosition par device.CursorPosition.
• 替换 device.CursorLocalVelocity par device.CursorVelocity.
• 替换 device.CursorSetLocalForce(force) par device.CursorSetForce(force).

private void OnDeviceStateChanged(object sender, Inverse3EventArgs args)
{
    var inverse3 = args.DeviceController;
    var force = ForceCalculation(inverse3.CursorPosition, inverse3.CursorVelocity,
        _cursorRadius, _ballPosition, _ballRadius);

    inverse3.SetCursorForce(force);
}

游戏体验

将光标移至“Inverse3 ”上，并切换至“Play Mode”。试着像前一个示例中那样触摸该球体。 此时，您应该能感受到精确的触觉反馈，这反映了应用于“Haptic Origin ”和“Haptic Controller”的变换效果。

源文件

该示例的完整场景及相关文件可从 Unity 包管理器的“Tutorials”示例中导入。

该示例场景包含一些额外的脚本，用于在运行时调整“Haptic Controller”和“Haptic Origin”。

SphereForceFeedback.cs

/*
 * Copyright 2024 Haply Robotics Inc. All rights reserved.
 */

using Haply.Inverse.DeviceControllers;
using Haply.Inverse.DeviceData;
using UnityEngine;

namespace Haply.Samples.Tutorials._3_DeviceSpaceTransform
{
    public class SphereForceFeedback : MonoBehaviour
    {
        // must assign in inspector
        public Inverse3Controller inverse3;

        [Range(0, 800)]
        // Stiffness of the force feedback.
        public float stiffness = 300f;

        [Range(0, 3)]
        public float damping = 1f;

        private Vector3 _ballPosition;
        private float _ballRadius;
        private float _cursorRadius;

        /// <summary>
        /// Stores the cursor and sphere transform data for access by the haptic thread.
        /// </summary>
        private void SaveSceneData()
        {
            var t = transform;
            _ballPosition = t.position;
            _ballRadius = t.lossyScale.x / 2f;

            _cursorRadius = inverse3.Cursor.Radius;
        }

        /// <summary>
        /// Saves the initial scene data cache.
        /// </summary>
        private void Awake()
        {
            inverse3 ??= FindFirstObjectByType<Inverse3Controller>();
            inverse3.Ready.AddListener((device, args) => SaveSceneData());
        }

        /// <summary>
        /// Subscribes to the DeviceStateChanged event.
        /// </summary>
        private void OnEnable()
        {
            inverse3.DeviceStateChanged += OnDeviceStateChanged;
        }

        /// <summary>
        /// Unsubscribes from the DeviceStateChanged event.
        /// </summary>
        private void OnDisable()
        {
            inverse3.DeviceStateChanged -= OnDeviceStateChanged;
            inverse3.Release();
        }

        /// <summary>
        /// Calculates the force based on the cursor's position and another sphere position.
        /// </summary>
        /// <param name="cursorPosition">The position of the cursor.</param>
        /// <param name="cursorVelocity">The velocity of the cursor.</param>
        /// <param name="cursorRadius">The radius of the cursor.</param>
        /// <param name="otherPosition">The position of the other sphere (e.g., ball).</param>
        /// <param name="otherRadius">The radius of the other sphere.</param>
        /// <returns>The calculated force vector.</returns>
        private Vector3 ForceCalculation(Vector3 cursorPosition, Vector3 cursorVelocity, float cursorRadius,
            Vector3 otherPosition, float otherRadius)
        {
            var force = Vector3.zero;

            var distanceVector = cursorPosition - otherPosition;
            var distance = distanceVector.magnitude;
            var penetration = otherRadius + cursorRadius - distance;

            if (penetration > 0)
            {
                // Normalize the distance vector to get the direction of the force
                var normal = distanceVector.normalized;

                // Calculate the force based on penetration
                force = normal * penetration * stiffness;

                // Apply damping based on the cursor velocity
                force -= cursorVelocity * damping;
            }

            return force;
        }

        /// <summary>
        /// Event handler that calculates and send the force to the device when the cursor's position changes.
        /// </summary>
        /// <param name="sender">The Inverse3 data object.</param>
        /// <param name="args">The event arguments containing the device data.</param>
        private void OnDeviceStateChanged(object sender, Inverse3EventArgs args)
        {
            var inverse3 = args.DeviceController;
            // Calculate the ball force. Using 'device.Position' instead of 'device.LocalPosition'
            // ensures the force calculation considers the device's offset and rotation in world space.
            var force = ForceCalculation(inverse3.CursorPosition, inverse3.CursorVelocity,
                _cursorRadius, _ballPosition, _ballRadius);

            // Apply the calculated force to the cursor. Using 'device.CursorSetForce' instead of
            // 'device.CursorSetLocalForce' ensures that the force vector is correctly converted
            // from world space to the device's local space.
            inverse3.SetCursorForce(force);
        }
    }
}