Unity教程之-Unity3d中wayPoint寻路的实现方式

 

unity3d中关于自动寻路的讲解我们在前面几篇文章提到过《Unity教程之-Unity3d自动寻路功能介绍演示》、《Unity插件之-Dynamic Navigation系统寻路扩展插件》、《Unity插件之-Dynamic Navigation系统寻路扩展插件》,本篇文章我们来看下wayPoint寻路的实现方式 ,

效果图:

wayPoint寻路

WaypointProgressTracker.cs 【固定】

WaypointCircuit.cs 【固定】

wayPoint寻路

贴上代码


using System;
using System.Collections;
using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;

#endif

namespace UnityStandardAssets.Utility
{
public class WaypointCircuit : MonoBehaviour
{
public WaypointList waypointList = new WaypointList();
[SerializeField] private bool smoothRoute = true;
private int numPoints;
private Vector3[] points;
private float[] distances;

public float editorVisualisationSubsteps = 100;
public float Length { get; private set; }

public Transform[] Waypoints
{
get { return waypointList.items; }
}

//this being here will save GC allocs
private int p0n;
private int p1n;
private int p2n;
private int p3n;

private float i;
private Vector3 P0;
private Vector3 P1;
private Vector3 P2;
private Vector3 P3;

// Use this for initialization
private void Awake()
{
if (Waypoints.Length > 1)
{
CachePositionsAndDistances();
}
numPoints = Waypoints.Length;
}

public RoutePoint GetRoutePoint(float dist)
{
// position and direction
Vector3 p1 = GetRoutePosition(dist);
Vector3 p2 = GetRoutePosition(dist + 0.1f);
Vector3 delta = p2 - p1;
return new RoutePoint(p1, delta.normalized);
}

public Vector3 GetRoutePosition(float dist)
{
int point = 0;

if (Length == 0)
{
Length = distances[distances.Length - 1];
}

dist = Mathf.Repeat(dist, Length);

while (distances[point] < dist)
{
++point;
}

// get nearest two points, ensuring points wrap-around start & end of circuit
p1n = ((point - 1) + numPoints)%numPoints;
p2n = point;

// found point numbers, now find interpolation value between the two middle points

i = Mathf.InverseLerp(distances[p1n], distances[p2n], dist);

if (smoothRoute)
{
// smooth catmull-rom calculation between the two relevant points

// get indices for the surrounding 2 points, because
// four points are required by the catmull-rom function
p0n = ((point - 2) + numPoints)%numPoints;
p3n = (point + 1)%numPoints;

// 2nd point may have been the 'last' point - a dupe of the first,
// (to give a value of max track distance instead of zero)
// but now it must be wrapped back to zero if that was the case.
p2n = p2n%numPoints;

P0 = points[p0n];
P1 = points[p1n];
P2 = points[p2n];
P3 = points[p3n];

return CatmullRom(P0, P1, P2, P3, i);
}
else
{
// simple linear lerp between the two points:

p1n = ((point - 1) + numPoints)%numPoints;
p2n = point;

return Vector3.Lerp(points[p1n], points[p2n], i);
}
}

private Vector3 CatmullRom(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float i)
{
// comments are no use here... it's the catmull-rom equation.
// Un-magic this, lord vector!
return 0.5f*
((2*p1) + (-p0 + p2)*i + (2*p0 - 5*p1 + 4*p2 - p3)*i*i +
(-p0 + 3*p1 - 3*p2 + p3)*i*i*i);
}

private void CachePositionsAndDistances()
{
// transfer the position of each point and distances between points to arrays for
// speed of lookup at runtime
points = new Vector3[Waypoints.Length + 1];
distances = new float[Waypoints.Length + 1];

float accumulateDistance = 0;
for (int i = 0; i < points.Length; ++i)
{
var t1 = Waypoints[(i)%Waypoints.Length];
var t2 = Waypoints[(i + 1)%Waypoints.Length];
if (t1 != null && t2 != null)
{
Vector3 p1 = t1.position;
Vector3 p2 = t2.position;
points[i] = Waypoints[i%Waypoints.Length].position;
distances[i] = accumulateDistance;
accumulateDistance += (p1 - p2).magnitude;
}
}
}

private void OnDrawGizmos()
{
DrawGizmos(false);
}

private void OnDrawGizmosSelected()
{
DrawGizmos(true);
}

private void DrawGizmos(bool selected)
{
waypointList.circuit = this;
if (Waypoints.Length > 1)
{
numPoints = Waypoints.Length;

CachePositionsAndDistances();
Length = distances[distances.Length - 1];

Gizmos.color = selected ? Color.yellow : new Color(1, 1, 0, 0.5f);
Vector3 prev = Waypoints[0].position;
if (smoothRoute)
{
for (float dist = 0; dist < Length; dist += Length/editorVisualisationSubsteps)
{
Vector3 next = GetRoutePosition(dist + 1);
Gizmos.DrawLine(prev, next);
prev = next;
}
Gizmos.DrawLine(prev, Waypoints[0].position);
}
else
{
for (int n = 0; n < Waypoints.Length; ++n)
{
Vector3 next = Waypoints[(n + 1)%Waypoints.Length].position;
Gizmos.DrawLine(prev, next);
prev = next;
}
}
}
}

[Serializable]
public class WaypointList
{
public WaypointCircuit circuit;
public Transform[] items = new Transform[0];
}

public struct RoutePoint
{
public Vector3 position;
public Vector3 direction;

public RoutePoint(Vector3 position, Vector3 direction)
{
this.position = position;
this.direction = direction;
}
}
}
}

namespace UnityStandardAssets.Utility.Inspector
{
#if UNITY_EDITOR
[CustomPropertyDrawer(typeof (WaypointCircuit.WaypointList))]
public class WaypointListDrawer : PropertyDrawer
{
private float lineHeight = 18;
private float spacing = 4;

public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
{
EditorGUI.BeginProperty(position, label, property);

float x = position.x;
float y = position.y;
float inspectorWidth = position.width;

// Draw label

// Don't make child fields be indented
var indent = EditorGUI.indentLevel;
EditorGUI.indentLevel = 0;

var items = property.FindPropertyRelative("items");
var titles = new string[] {"Transform", "", "", ""};
var props = new string[] {"transform", "^", "v", "-"};
var widths = new float[] {.7f, .1f, .1f, .1f};
float lineHeight = 18;
bool changedLength = false;
if (items.arraySize > 0)
{
for (int i = -1; i < items.arraySize; ++i)
{
var item = items.GetArrayElementAtIndex(i);

float rowX = x;
for (int n = 0; n < props.Length; ++n)
{
float w = widths[n]*inspectorWidth;

// Calculate rects
Rect rect = new Rect(rowX, y, w, lineHeight);
rowX += w;

if (i == -1)
{
EditorGUI.LabelField(rect, titles[n]);
}
else
{
if (n == 0)
{
EditorGUI.ObjectField(rect, item.objectReferenceValue, typeof (Transform), true);
}
else
{
if (GUI.Button(rect, props[n]))
{
switch (props[n])
{
case "-":
items.DeleteArrayElementAtIndex(i);
items.DeleteArrayElementAtIndex(i);
changedLength = true;
break;
case "v":
if (i > 0)
{
items.MoveArrayElement(i, i + 1);
}
break;
case "^":
if (i < items.arraySize - 1)
{
items.MoveArrayElement(i, i - 1);
}
break;
}
}
}
}
}

y += lineHeight + spacing;
if (changedLength)
{
break;
}
}
}
else
{
// add button
var addButtonRect = new Rect((x + position.width) - widths[widths.Length - 1]*inspectorWidth, y,
widths[widths.Length - 1]*inspectorWidth, lineHeight);
if (GUI.Button(addButtonRect, "+"))
{
items.InsertArrayElementAtIndex(items.arraySize);
}

y += lineHeight + spacing;
}

// add all button
var addAllButtonRect = new Rect(x, y, inspectorWidth, lineHeight);
if (GUI.Button(addAllButtonRect, "Assign using all child objects"))
{
var circuit = property.FindPropertyRelative("circuit").objectReferenceValue as WaypointCircuit;
var children = new Transform[circuit.transform.childCount];
int n = 0;
foreach (Transform child in circuit.transform)
{
children[n++] = child;
}
Array.Sort(children, new TransformNameComparer());
circuit.waypointList.items = new Transform[children.Length];
for (n = 0; n < children.Length; ++n)
{
circuit.waypointList.items[n] = children[n];
}
}
y += lineHeight + spacing;

// rename all button
var renameButtonRect = new Rect(x, y, inspectorWidth, lineHeight);
if (GUI.Button(renameButtonRect, "Auto Rename numerically from this order"))
{
var circuit = property.FindPropertyRelative("circuit").objectReferenceValue as WaypointCircuit;
int n = 0;
foreach (Transform child in circuit.waypointList.items)
{
child.name = "Waypoint " + (n++).ToString("000");
}
}
y += lineHeight + spacing;

// Set indent back to what it was
EditorGUI.indentLevel = indent;
EditorGUI.EndProperty();
}

public override float GetPropertyHeight(SerializedProperty property, GUIContent label)
{
SerializedProperty items = property.FindPropertyRelative("items");
float lineAndSpace = lineHeight + spacing;
return 40 + (items.arraySize*lineAndSpace) + lineAndSpace;
}

// comparer for check distances in ray cast hits
public class TransformNameComparer : IComparer
{
public int Compare(object x, object y)
{
return ((Transform) x).name.CompareTo(((Transform) y).name);
}
}
}
#endif
}

 

wayPoint寻路


using System;
using UnityEngine;

namespace UnityStandardAssets.Utility
{
public class WaypointProgressTracker : MonoBehaviour
{
// This script can be used with any object that is supposed to follow a
// route marked out by waypoints.

// This script manages the amount to look ahead along the route,
// and keeps track of progress and laps.

[SerializeField] private WaypointCircuit circuit; // A reference to the waypoint-based route we should follow

[SerializeField] private float lookAheadForTargetOffset = 5;
// The offset ahead along the route that the we will aim for

[SerializeField] private float lookAheadForTargetFactor = .1f;
// A multiplier adding distance ahead along the route to aim for, based on current speed

[SerializeField] private float lookAheadForSpeedOffset = 10;
// The offset ahead only the route for speed adjustments (applied as the rotation of the waypoint target transform)

[SerializeField] private float lookAheadForSpeedFactor = .2f;
// A multiplier adding distance ahead along the route for speed adjustments

[SerializeField] private ProgressStyle progressStyle = ProgressStyle.SmoothAlongRoute;
// whether to update the position smoothly along the route (good for curved paths) or just when we reach each waypoint.

[SerializeField] private float pointToPointThreshold = 4;
// proximity to waypoint which must be reached to switch target to next waypoint : only used in PointToPoint mode.

public enum ProgressStyle
{
SmoothAlongRoute,
PointToPoint,
}

// these are public, readable by other objects - i.e. for an AI to know where to head!
public WaypointCircuit.RoutePoint targetPoint { get; private set; }
public WaypointCircuit.RoutePoint speedPoint { get; private set; }
public WaypointCircuit.RoutePoint progressPoint { get; private set; }

public Transform target;

private float progressDistance; // The progress round the route, used in smooth mode.
private int progressNum; // the current waypoint number, used in point-to-point mode.
private Vector3 lastPosition; // Used to calculate current speed (since we may not have a rigidbody component)
private float speed; // current speed of this object (calculated from delta since last frame)

// setup script properties
private void Start()
{
// we use a transform to represent the point to aim for, and the point which
// is considered for upcoming changes-of-speed. This allows this component
// to communicate this information to the AI without requiring further dependencies.

// You can manually create a transform and assign it to this component *and* the AI,
// then this component will update it, and the AI can read it.
if (target == null)
{
target = new GameObject(name + " Waypoint Target").transform;
}

Reset();
}

// reset the object to sensible values
public void Reset()
{
progressDistance = 0;
progressNum = 0;
if (progressStyle == ProgressStyle.PointToPoint)
{
target.position = circuit.Waypoints[progressNum].position;
target.rotation = circuit.Waypoints[progressNum].rotation;
}
}

private void Update()
{
if (progressStyle == ProgressStyle.SmoothAlongRoute)
{
// determine the position we should currently be aiming for
// (this is different to the current progress position, it is a a certain amount ahead along the route)
// we use lerp as a simple way of smoothing out the speed over time.
if (Time.deltaTime > 0)
{
speed = Mathf.Lerp(speed, (lastPosition - transform.position).magnitude/Time.deltaTime,
Time.deltaTime);
}
target.position =
circuit.GetRoutePoint(progressDistance + lookAheadForTargetOffset + lookAheadForTargetFactor*speed)
.position;
target.rotation =
Quaternion.LookRotation(
circuit.GetRoutePoint(progressDistance + lookAheadForSpeedOffset + lookAheadForSpeedFactor*speed)
.direction);

// get our current progress along the route
progressPoint = circuit.GetRoutePoint(progressDistance);
Vector3 progressDelta = progressPoint.position - transform.position;
if (Vector3.Dot(progressDelta, progressPoint.direction) < 0)
{
progressDistance += progressDelta.magnitude*0.5f;
}

lastPosition = transform.position;
}
else
{
// point to point mode. Just increase the waypoint if we're close enough:

Vector3 targetDelta = target.position - transform.position;
if (targetDelta.magnitude < pointToPointThreshold)
{
progressNum = (progressNum + 1)%circuit.Waypoints.Length;
}

target.position = circuit.Waypoints[progressNum].position;
target.rotation = circuit.Waypoints[progressNum].rotation;

// get our current progress along the route
progressPoint = circuit.GetRoutePoint(progressDistance);
Vector3 progressDelta = progressPoint.position - transform.position;
if (Vector3.Dot(progressDelta, progressPoint.direction) < 0)
{
progressDistance += progressDelta.magnitude;
}
lastPosition = transform.position;
}
}

private void OnDrawGizmos()
{
if (Application.isPlaying)
{
Gizmos.color = Color.green;
Gizmos.DrawLine(transform.position, target.position);
Gizmos.DrawWireSphere(circuit.GetRoutePosition(progressDistance), 1);
Gizmos.color = Color.yellow;
Gizmos.DrawLine(target.position, target.position + target.forward);
}
}
}
}

最后: 看看Unity5的 sample中的 Car 和 飞机 的AI案例中:

wayPoint寻路

wayPoint寻路

wayPoint寻路

wayPoint寻路

好了,本篇unity3d教程到此结束,下篇我们再会!