创建一条曲线以显示对象将在Unity中投影的位置

Question

我有一些代码，下面是沿着曲线将对象投影到给定位置的代码，它可以完美地工作。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Move : MonoBehaviour {
public GameObject platform;
public Vector3 targetPos;
public float speed = 10;
public float arcHeight = 1;
Vector3 startPos;
GameObject line;

// Use this for initialization
void Start () {
startPos = transform.position;
targetPos = platform.transform.position;
targetPos.x -= 0.7f;
targetPos.y += 1.5f;
}
// Update is called once per frame
void Update () {
movePlayer();
}

void movePlayer()
{
// Compute the next position, with arc added in
float x0 = startPos.x;
float x1 = targetPos.x;
float dist = x1 - x0;
float nextX = Mathf.MoveTowards(transform.position.x, x1, speed * Time.deltaTime);
float baseY = Mathf.Lerp(startPos.y, targetPos.y, (nextX - x0) / dist);
float arc = arcHeight * (nextX - x0) * (nextX - x1) / (-0.25f * dist * dist);
Vector3 nextPos = new Vector3(nextX, baseY + arc, transform.position.z);

transform.position = nextPos;
// Do something when we reach the target
if (nextPos == targetPos) Arrived();
}
void Arrived()
{
Destroy(gameObject);
}
}

我希望现在能够添加一条可见的曲线，显示对象的路径。我看到了一些使用LineRenderer的例子，但我不确定如何将其结合到移动对象的方式中。任何关于如何做到这一点的帮助都将不胜感激。

Answer 1

我编辑了您的代码，让LineRenderer创建一个路径。其想法是，使用一个位置作为下一个位置的输入，提前生成对象的坐标。(所以不仅仅取决于对象的变换(。

一定要在检查器中设置一个Material，否则你只会看到一条粉红色的线。我希望这就是你的想法。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public class Move : MonoBehaviour
{
public GameObject platform;
public Vector3 targetPos;
public float speed = 10;
public float arcHeight = 1;
Vector3 startPos;
GameObject line;
/// <summary>
/// Our linerenderer
/// </summary>
private LineRenderer lineRenderer;
/// <summary>
/// Line material.
/// </summary>
[SerializeField]
private Material lineMaterial;
// Use this for initialization
private void Start()
{
startPos = transform.position;
targetPos = platform.transform.position;
targetPos.x -= 0.7f;
targetPos.y += 1.5f;
// Add a linerenderer.
lineRenderer = gameObject.AddComponent<LineRenderer>();
if (lineMaterial == null)
{
Debug.LogError("No LineMaterial specified!");
}
// If you do not want to use worldspace, set this to false:
lineRenderer.useWorldSpace = true;
// Set preferred texture mode for texture.
lineRenderer.textureMode = LineTextureMode.RepeatPerSegment;
// Shadows, or not?
//lineRenderer.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.Off;
//lineRenderer.receiveShadows = false;
// Finally, set the material that you want to assign.
// Remember: If you use default shader, it needs to be set to "Transparent" to get your texture's alpha working.
lineRenderer.sharedMaterial = lineMaterial;

}
// Update is called once per frame
private void Update()
{
movePlayer();
}
private void movePlayer()
{
// Compute the next position, with arc added in
Vector3 nextPos = newPosition(transform.position, speed * Time.deltaTime);
transform.position = nextPos;
// Calculate upcoming positions.
Vector3[] points = generateUpcomingPositions(nextPos);
CreateLine(points);

// Do something when we reach the target
if (nextPos == targetPos) Arrived();
}
private Vector3 newPosition(Vector3 currentPosition, float delta)
{
float x0 = startPos.x;
float x1 = targetPos.x;
float dist = x1 - x0;
float nextX = Mathf.MoveTowards(currentPosition.x, x1, delta);
float baseY = Mathf.Lerp(startPos.y, targetPos.y, (nextX - x0) / dist);
float arc = arcHeight * (nextX - x0) * (nextX - x1) / (-0.25f * dist * dist);
Vector3 nextPos = new Vector3(nextX, baseY + arc, currentPosition.z);
return nextPos;
}
private Vector3[] generateUpcomingPositions(Vector3 currentPosition)
{
int steps = 10;
float delta = (1.0f / ((steps - 1))) * 2.0f;// Double delta.
List<Vector3> points = new List<Vector3>();
Vector3 newPos = currentPosition;
for (int i = 0; i < steps; i++)
{
// Use newPos as input for location.
newPos = newPosition(newPos, delta * i);
points.Add(newPos);
}
return points.ToArray();
}

private void Arrived()
{
Destroy(gameObject);
}
/// <summary>
/// Create a line with a given name, width and points.
/// </summary>
/// <param name="points"></param>
private void CreateLine(Vector3[] points)
{
// Set the positions.
lineRenderer.positionCount = points.Length;
lineRenderer.SetPositions(points);
}
}