我已经在这个项目上工作了一段时间 - 我一直在尝试制作一个简单的立方体，玩家可以使用箭头向左或向右移动，能够围绕管道旋转，类似于赛车手可以围绕管道移动在 F-零 GX 中：
https://www.youtube.com/watch?v=RlS1i7aCnvg
现在，我知道我不是第一个尝试实施这些物理学的人，因为我已经阅读了两三个试图实施类似技术的人的帖子。问题是我尝试过使用这些不同的方法或它们的变体。其中一个已经非常接近我想要的行为 - 但是玩家立方体仍然会在立方体从地面超过整个管道壁的一半后意外地在其 X 轴上旋转。这是我正在谈论的关卡构建的视觉效果：
整个想法是，立方体可以围绕管道的整个壁“移动”或“行走”，就像您在 F-Zero 视频的管道部分中看到的那样，当然仍然向前移动。我有一个圆柱体，它实际上在你看到的那个圆柱体内部，它实际上只是一个凸面触发器 - 因此用于确保当立方体位于管道模型内时玩家立方体的重力刻度关闭。
我已经接近完成这项工作，但问题是看到玩家能够一直移动一个完整的圆圈，即。以圆周运动完全回到底部或玩家进入管道时开始的位置。然而，当它完成墙壁移动的一半多一点时，立方体喜欢“翻转”。我一直在另一篇文章中读到有人实际上改变了物体的刚体以使“船”保持直立，这与它有关吗？
https://forum.unity.com/threads/f-zero-esque-control-question.157909/
“基本上我给了我的车一条悬浮裙。”
我应该考虑相应地改变刚体的形状吗？执行此操作的最佳资源是什么？或者也许我应该使用字符控制器？我仍然依靠刚体设置，但在阅读了这些内容后，我已经对这种可能性敞开了心扉。
这个 Raycast 代码非常接近我想要的，没有骰子：
float distDown = Mathf.Infinity;
RaycastHit hitDown;
if (Physics.SphereCast(transform.position, 0.25f, -transform.up, out hitDown, 5))
{
distDown = hitDown.distance;
}
transform.rotation = Quaternion.Lerp(transform.rotation, Quaternion.LookRotation(Vector3.Cross(transform.right, hitDown.normal), hitDown.normal), Time.deltaTime * 1.0f);
我尝试探索的另一种可能性是创建自己的重力拉力——我什至有一个尝试这样做的类，FauxGravity，它附加到玩家碰撞的对象（在本例中为圆柱体）：
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class FauxGravity : MonoBehaviour {
public Transform attractor;
public Transform player;
public Transform collider;
Rigidbody attractRB;
Rigidbody playerRB;
Vector3 myNormal;
public Vector3 vectorFromPipeCenter;
public Vector3 forwardPipeVector;
Vector3 project2Center;
public Vector3 pipeGravityPull;
public int gravity = 1;
// Use this for initialization
void Start () {
//Physics.gravity.magnitude = 0;
}
// Update is called once per frame
void Update () {
}
//private void OnCollisionEnter(Collision collision)
//{
// //collision.gameObject.GetComponent<Rigidbody>().transform.up = Vector3.zero;
// //player.gameObject.GetComponent<Rigidbody>().useGravity = false;
// myNormal = playerRB.transform.up;
// //playerRB = collision.gameObject.GetComponent<Rigidbody>();
// gravity = 0;
// //playerRB.isKinematic = true;
// //player.gameObject.GetComponent<Rigidbody>().AddRelativeForce()
//}
public void FixedUpdate()
{
if (gravity == 0)
{
//playerRB.isKinematic = true;
//Debug.Log("Gravity is 0.");
attractRB = attractor.GetComponent<Rigidbody>();
playerRB = player.GetComponent<Rigidbody>();
//playerRB.AddForce(-10 * playerRB.mass * myNormal);
Debug.Log("PlayerRB position: " + playerRB.position);
Debug.Log("AttractRB position: " + attractRB.position);
vectorFromPipeCenter = playerRB.position - attractRB.position;
vectorFromPipeCenter.z = 0;
//vectorFromPipeCenter.Normalize();
Debug.Log("Player distance from pipe center: " + vectorFromPipeCenter.magnitude);
Debug.Log("Player vector from pipe center" + vectorFromPipeCenter);
//vectorFromPipeCenter = attractRB.position - playerRB.position;
Debug.Log("playerRB forward is " + playerRB.rotation.z);
Debug.Log("playerRB magnitude is " + player.forward.magnitude);
forwardPipeVector = player.forward.magnitude * Vector3.forward;
Debug.Log("Player forward vector? " + forwardPipeVector);
// or
//Vector forwardPipeVector = pipeTransform.forward;
// And finally
project2Center = Vector3.Project(vectorFromPipeCenter, forwardPipeVector);
Debug.Log("What is project2Center? " + project2Center);
float radiusFromCrossectionCenter = vectorFromPipeCenter.magnitude;
double playerY = System.Convert.ToDouble(playerRB.position.y);
double playerX = System.Convert.ToDouble(playerRB.position.x);
//float inverseTan = System.Convert.ToSingle(System.Math.Atan(playerY / playerX));
//Debug.Log("Normal is: " + Quaternion.AngleAxis(inverseTan, forwardPipeVector));
// pipe pull force = distance from pipe center to power 2
//pipeGravityPull = Quaternion.AngleAxis(inverseTan, playerRB.transform.forward) * project2Center * Mathf.Pow ( (radiusFromCrossectionCenter * 1 ), 2 );
pipeGravityPull = new Vector3(playerRB.position.x, radiusFromCrossectionCenter - playerRB.position.y, 0)/Mathf.Sqrt(Mathf.Pow(playerRB.position.x,2) + Mathf.Pow((radiusFromCrossectionCenter-playerRB.position.y),2));
Debug.Log("Pipe gravity vector? " + pipeGravityPull);
//playerRB.useGravity = true;
Debug.DrawLine(pipeGravityPull, pipeGravityPull);
Debug.Log("Adding force from FG");
//playerRB.AddForce(pipeGravityPull);
}
if (gravity == 1)
{
player.GetComponent<Rigidbody>().useGravity = true;
//playerRB.isKinematic = false;
}
}
private void OnCollisionExit(Collision collision)
{
//Debug.Log("Gravity is 1 again.");
//player.gameObject.GetComponent<Rigidbody>().useGravity = true;
//gravity = 1;
//playerRB.useGravity = true;
playerRB.isKinematic = false;
//playerRB.AddForce(10, 20, 0);
}
void gravityAttract(Collider colliderObject)
{
var rb = colliderObject.GetComponent<Rigidbody>();
rb.AddForce(Vector3.down * 30, ForceMode.Force);
rb.AddForce(Vector3.up * 30, ForceMode.Force);
}
}
我是否需要将我的 FixedUpdate 逻辑移动到 Update 方法？根据我父亲的说法（他是天体物理学家），我在这种方法中探索的最后一个算法本质上是通过将玩家的矢量与他/她正在行进的管道的横截面相乘来确保拉力始终等于 1 .
这是我的玩家的移动类，它有几个已注释和未注释的尝试旋转立方体，以使立方体的下侧在攀爬时始终面向管壁：
using System;
using UnityEngine;
public class PlayerMovement : MonoBehaviour {
public Rigidbody rb;
public float forwardForce = 2000f;
public float sidewaysForce = 500f;
public Boolean fauxGravity = false;
public Vector3 distanceFromPipeCenter = new Vector3(0, 0, 0);
public Vector3 pipePull = new Vector3(0,0,0);
// Use this for initialization
void Start () {
}
// Update is called once per frame use fixed update for Unity Fizzix
void FixedUpdate () {
//distanceFromPipeCenter.Normalize();
//add forward force
rb.AddForce(0, 0, forwardForce * Time.deltaTime);
if (Input.GetKey(KeyCode.RightArrow)/* && !fauxGravity*/)
{
rb.AddForce(sidewaysForce * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
}
if (Input.GetKey(KeyCode.LeftArrow)/* && !fauxGravity*/)
{
rb.AddForce(-sidewaysForce * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
}
if (pipePull.x == 0)
{
pipePull.x = 1;
}
if (pipePull.y == 0)
{
pipePull.y = 1;
}
//transform.rotation = Quaternion.identity;
//pipePull.z = 0;
if (Input.GetKey(KeyCode.RightArrow) && fauxGravity)
{
Debug.Log("Right pressed");
//Debug.Log("Rotation before: " + rb.rotation);
//rb.rotation = rb.rotation * Quaternion.FromToRotation(rb.transform.up, pipePull);
//rb.rotation = Quaternion.Lerp(rb.rotation, Quaternion.LookRotation(Vector3.Cross(rb.transform.right, pipePull), pipePull), Time.deltaTime * 5.0f);
//Debug.Log("Rotation after: " + rb.rotation);
//if (distanceFromPipeCenter.y < 0)
//{
// Debug.Log("Right A, pull positive: " +pipePull);
//rb.AddForce(sidewaysForce * pipePull.x * Time.deltaTime, sidewaysForce * pipePull.y * Time.deltaTime, 0, ForceMode.VelocityChange);
//}
//else
//{
// Debug.Log("Right B, pull negative: " + distanceFromPipeCenter);
// rb.AddForce(sidewaysForce * pipePull.x * Time.deltaTime, -sidewaysForce * pipePull.y * Time.deltaTime, 0, ForceMode.VelocityChange);
//}
//Debug.Log(rb.angularVelocity);
//float headingDeltaAngle = Input.GetAxis("Horizontal") * Time.deltaTime * sidewaysForce;
//Quaternion headingDelta = Quaternion.AngleAxis(headingDeltaAngle, transform.up);
//align with surface normal
//transform.rotation = Quaternion.FromToRotation(transform.up, distanceFromPipeCenter) * transform.rotation;
//apply heading rotation
//transform.rotation = headingDelta * transform.rotation;
}
if (Input.GetKey(KeyCode.LeftArrow) && fauxGravity)
{
Debug.Log("Left pressed");
//Debug.Log("Rotation before: " + rb.rotation);
//rb.rotation = rb.rotation * Quaternion.FromToRotation(rb.transform.up, pipePull);
//rb.rotation = Quaternion.Lerp(rb.rotation, Quaternion.LookRotation(Vector3.Cross(rb.transform.right, pipePull), pipePull), Time.deltaTime * 5.0f);
//Debug.Log("Rotation after: " + rb.rotation);
//if (distanceFromPipeCenter.y < 0)
//{
// Debug.Log("Left A, pull positive: " +pipePull);
//rb.AddForce(-sidewaysForce * pipePull.x * Time.deltaTime, sidewaysForce * pipePull.y * Time.deltaTime, 0, ForceMode.VelocityChange);
//}
//else
//{
// Debug.Log("Left B, pull negative: " + distanceFromPipeCenter);
// rb.AddForce(-sidewaysForce * pipePull.x * Time.deltaTime, -sidewaysForce * pipePull.y * Time.deltaTime, 0, ForceMode.VelocityChange);
//}
//Debug.Log(rb.angularVelocity);
//float headingDeltaAngle = Input.GetAxis("Horizontal") * Time.deltaTime * sidewaysForce;
//Quaternion headingDelta = Quaternion.AngleAxis(headingDeltaAngle, transform.up);
//align with surface normal
//transform.rotation = Quaternion.FromToRotation(transform.up, distanceFromPipeCenter) * transform.rotation;
//apply heading rotation
//transform.rotation = headingDelta * transform.rotation;
}
if (fauxGravity)
{
rb.useGravity = false;
///*We get the user input and modifiy the direction the ship will face towards*/
//float yaw = Time.deltaTime * Input.GetAxis("Horizontal");
///*We want to save our current transform.up vector so we can smoothly change it later*/
//Vector3 prev_up = rb.transform.up;
///*Now we set all angles to zero except for the Y which corresponds to the Yaw*/
//transform.rotation = Quaternion.Euler(0, yaw, 0);
//RaycastHit hit;
//if (Physics.Raycast(transform.position, -prev_up, out hit))
//{
// Debug.DrawLine(transform.position, hit.point);
// /*Here are the meat and potatoes: first we calculate the new up vector for the ship using lerp so that it is smoothed*/
// Vector3 desired_up = Vector3.Lerp(prev_up, hit.normal, Time.deltaTime /** pitch_smooth*/);
// /*Then we get the angle that we have to rotate in quaternion format*/
// Quaternion tilt = Quaternion.FromToRotation(transform.up, desired_up);
// /*Now we apply it to the ship with the quaternion product property*/
// transform.rotation = tilt * transform.rotation;
// /*Smoothly adjust our height*/
// //smooth_y = Mathf.Lerp(smooth_y, hover_height - hit.distance, Time.deltaTime * height_smooth);
// //transform.localPosition += prev_up * smooth_y;
//}
//float distForward = Mathf.Infinity;
//RaycastHit hitForward;
//if (Physics.SphereCast(transform.position, 0.25f, -transform.up + transform.forward, out hitForward, 5))
//{
// distForward = hitForward.distance;
//}
float distDown = Mathf.Infinity;
RaycastHit hitDown;
if (Physics.SphereCast(transform.position, 0.25f, -transform.up, out hitDown, 5))
{
distDown = hitDown.distance;
}
//float distBack = Mathf.Infinity;
//RaycastHit hitBack;
//if (Physics.SphereCast(transform.position, 0.25f, -transform.up + -transform.forward, out hitBack, 5))
//{
// distBack = hitBack.distance;
//}
//if (distForward < distDown && distForward < distBack)
//{
// transform.rotation = Quaternion.Lerp(transform.rotation, Quaternion.LookRotation(Vector3.Cross(transform.right, hitForward.normal), hitForward.normal), Time.deltaTime * 5.0f);
//}
//else if (distDown < distForward && distDown < distBack)
//{
transform.rotation = Quaternion.Lerp(transform.rotation, Quaternion.LookRotation(Vector3.Cross(transform.right, hitDown.normal), hitDown.normal), Time.deltaTime * 1.0f);
//}
//else if (distBack < distForward && distBack < distDown)
//{
// transform.rotation = Quaternion.Lerp(transform.rotation, Quaternion.LookRotation(Vector3.Cross(transform.right, hitBack.normal), hitBack.normal), Time.deltaTime * 5.0f);
//}
//GetComponent<Rigidbody>().AddForce(-transform.up * Time.deltaTime * 10);
}
if (rb.position.y <-1f)
{
FindObjectOfType<GameManagement>().EndGame();
}
}
//void OnCollisionEnter(Collision collision)
//{
// //collision.gameObject.GetComponent<Rigidbody>().transform.up = Vector3.zero;
// //player.gameObject.GetComponent<Rigidbody>().useGravity = false;
// System.Console.WriteLine("Player has collided with: " + collision.collider.name);
// if(collision.gameObject.name == "PipeBasic 1")
// {
// System.Console.WriteLine("Player Collided with Pipe");
// fauxGravity = true;
// }
// //playerRB.isKinematic = true;
// //player.gameObject.GetComponent<Rigidbody>().AddRelativeForce()
//}
}
任何人都可以提供一些额外的提示、提示和技巧吗？我认为使用 Raycast，甚至是其中的 SphereCast，可能是最接近我想要的方法，但我只是坚持如何在不冒险旋转玩家立方体的情况下准确实现它错误的一面并搞砸了物理相互作用。是不是我想太多了？
非常感谢大家。
更新：
我一直在改变玩家 Y 速度的逻辑，因为绕圈移动必须涉及特定的物理特性，如下页给出的等式：
https://www.physicsclassroom.com/class/circles/Lesson-1/Speed-and-Velocity
但是，我仍在努力寻找一个好的时间值来划分等式的顶部。这是我向右移动时的移动代码：
if (distanceFromPipeCenter.y < 0)
{
//Debug.Log("Right A, pull positive: " + pipePull);
//Debug.Log("X Pull: " + pipePull.x);
rb.AddForce(sidewaysForce /** pipePull.x*/ * Time.deltaTime, (sidewaysForce * 2 * radiusInPipe * (float)Math.PI) / Time.deltaTime, 0, ForceMode.VelocityChange);
}
else if(distanceFromPipeCenter.x>=3)
{
//Debug.Log("Right B, pull negative: " + distanceFromPipeCenter);
rb.AddForce(-sidewaysForce /** pipePull.x*/ * Time.deltaTime, (sidewaysForce * 2 * radiusInPipe * (float)Math.PI) / Time.deltaTime, 0, ForceMode.VelocityChange);
}
else if(distanceFromPipeCenter.x>0)
{
rb.AddForce(-sidewaysForce /** pipePull.x*/ * Time.deltaTime, (sidewaysForce * 2 * radiusInPipe * (float)Math.PI) / Time.deltaTime, 0, ForceMode.VelocityChange);
}
else if(distanceFromPipeCenter.y>0)
{
Debug.Log("X distance: " + distanceFromPipeCenter.x);
Debug.Log("Radius: " + radiusInPipe);
Debug.Log("Frame count? " + Time.fixedDeltaTime);
Vector3 pull = new Vector3(-sidewaysForce /** pipePull.x*/ * Time.deltaTime, ((-sidewaysForce * 2 * radiusInPipe * (float)Math.PI) / Time.fixedDeltaTime) * Time.deltaTime, 0);
Debug.Log("About to apply: " + pull );
rb.AddForce(-sidewaysForce /** pipePull.x*/ * Time.deltaTime, (-sidewaysForce * 2 * radiusInPipe * (float)Math.PI) / Time.deltaTime, 0, ForceMode.VelocityChange);
}
else
{
rb.AddForce(sidewaysForce /** pipePull.x*/ * Time.deltaTime, (-sidewaysForce * 2 * radiusInPipe * (float)Math.PI) / Time.deltaTime, 0, ForceMode.VelocityChange);
}
似乎除以 Time.deltaTime 只是让玩家跳了很远的距离——这不是我想要的。我还尝试使用自游戏开始以来的时间量作为除法器，然后将整个结果乘以 Time.deltaTime - 但正如您可能推断的那样，帧只是增加，然后最终以这种方式减慢速度.
有什么进一步的想法或建议吗？
