Unity实现汽车前后轮倒车轨迹计算

Unity实现汽车前后轮倒车轨迹计算

在Unity中实现汽车前后轮倒车轨迹的计算是一个常见的需求，特别是在开发赛车游戏或模拟驾驶游戏时。本文将详细介绍如何通过C#代码实现这一功能，包括必要的参数设置和具体的数学原理。

汽车前后轮倒车轨迹计算附C#源码(Unity)，具体内容如下：

原理很简单，都是高中的几何数学部分。

需要的参数有：

• 车前后轴距
• 车宽（左前轮与右前轮距离）
• 当前车轮角度（多数车33.5°）
• 是否要绘制前轮轨迹线

///<summary>
/// 获取行车轨迹预测index = 0 left轨迹
/// </summary>
/// <param name="steeringAngle">方向盘角度</param>
/// <param name="carWheelbase">汽车前后轴距</param>
/// <param name="carWidth">车宽</param>
/// <param name="length">点位密度</param>
/// <param name="isFront">是否是前轮</param>
/// <param name="maxAngle">轨迹的最大转弯角度</param>
/// <returns>交叉数组,下标为0的是右边线, 下表为1的是左边线</returns>
public Vector3[][] GetCarTrack(float steeringAngle, float carWheelbase, float carWidth, float length, bool isFront, float maxAngle = 90f)
 {
 float maxSteerAngle = _carControl._vehicleController.steering.maxSteerAngle;
 float theta = Mathf.Abs(steeringAngle / 180 * Mathf.PI);
 Vector3[][] track = new Vector3[2][];
 List<Vector3> trackLeft = new List<Vector3>();
 List<Vector3> trackRight = new List<Vector3>();
 if (theta == 0)
 {
 for (float i = 0; i < length; i++)
 {
 float x = i / length * 5;
 if (isFront)
 {
 x *= 1;
 trackLeft.Add(new Vector3(x, 0f, carWidth));
 trackRight.Add(new Vector3(x, 0f, 0f));
 }
 else
 {
 x *= -1;
 trackLeft.Add(new Vector3(x, 0, carWidth));
 trackRight.Add(new Vector3(x, 0, 0));
 }
 }
 }
 else
 {
 if (isFront)
 {
 float r = (carWheelbase / Mathf.Tan(theta) + carWidth / 2) / Mathf.Cos(theta);
 float rMin = Mathf.Cos(theta) * r - carWidth;
 float theta1 = Mathf.Atan(carWheelbase / rMin);
 rMin = rMin / Mathf.Cos(theta1);
 float rMax = rMin + carWidth;
 float lineAngle = carWheelbase / (rMax * 2f * Mathf.PI) * 360f;
 for (int i = 0; i <= length; i++)
 {
 if (i / length >= (maxAngle - lineAngle) / maxAngle)
 {
 float x = rMin * Mathf.Cos(maxAngle / length * i * Mathf.Deg2Rad);
 float z = rMin * Mathf.Sin(maxAngle / length * i * Mathf.Deg2Rad);
 if (x >= carWheelbase)
 {
 if (steeringAngle > 0)
 {
 trackRight.Add(new Vector3(x - carWheelbase, 0, z - rMin + steeringAngle / maxSteerAngle * (carWidth / 2)));
 }
 else
 {
 trackRight.Add(new Vector3(x - carWheelbase, 0, -(z - rMin) + carWidth + steeringAngle / maxSteerAngle * (carWidth / 2)));
 }
 }
 x = rMax * Mathf.Cos(maxAngle / length * i * Mathf.Deg2Rad);
 z = rMax * Mathf.Sin(maxAngle / length * i * Mathf.Deg2Rad);
 if (x >= carWheelbase)
 {
 if (steeringAngle > 0)
 {
 trackLeft.Add(new Vector3(x - carWheelbase, 0, z - rMin + steeringAngle / maxSteerAngle * (carWidth / 2)));
 }
 else
 {
 trackLeft.Add(new Vector3(x - carWheelbase, 0, -(z - rMin) + carWidth + steeringAngle / maxSteerAngle * (carWidth / 2)));
 }
 }
 }
 }
 trackRight[trackRight.Count - 1] = Vector3.forward * trackRight[trackRight.Count - 1].z;
 trackLeft[trackLeft.Count - 1] = Vector3.forward * trackLeft[trackLeft.Count - 1].z;
 }
 else
 {
 float r = (carWheelbase / Mathf.Tan(theta) + carWidth / 2) / Mathf.Cos(theta);
 float rMin = Mathf.Cos(theta) * r - carWidth;
 float rMax = rMin + carWidth;
 float lineAngle = carWheelbase / (rMin * 2f * Mathf.PI) * 360f;
 for (int i = 0; i <= length; i++)
 {
 if (i / length >= (maxAngle - lineAngle) / maxAngle)
 {
 float x = -rMin * Mathf.Cos(maxAngle / length * i * Mathf.Deg2Rad);
 float z = rMin * Mathf.Sin(maxAngle / length * i * Mathf.Deg2Rad);
 if (steeringAngle > 0)
 {
 trackRight.Add(new Vector3(x, 0, z - rMin));
 }
 else
 {
 trackRight.Add(new Vector3(x, 0, -(z - rMin) + carWidth));
 }
 x = -rMax * Mathf.Cos(maxAngle / length * i * Mathf.Deg2Rad);
 z = rMax * Mathf.Sin(maxAngle / length * i * Mathf.Deg2Rad);
 if (steeringAngle > 0)
 {
 trackLeft.Add(new Vector3(x, 0, z - rMin));
 }
 else
 {
 trackLeft.Add(new Vector3(x, 0, -(z - rMin) + carWidth));
 }
 }
 }
 trackRight[trackRight.Count - 1] = Vector3.forward * trackRight[trackRight.Count - 1].z;
 trackLeft[trackLeft.Count - 1] = Vector3.forward * trackLeft[trackLeft.Count - 1].z;
 }
 }
 track[0] = trackLeft.ToArray();
 track[1] = trackRight.ToArray();
 trackLeft = trackRight = null;
 return track;
}

以上就是本文的全部内容，希望对大家的学习有所帮助。