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using UnityEngine;
using System.Collections;
using System.Collections.Generic;
public class BezierCurveScript : MonoBehaviour {
public class BezierPath
{
public List<Vector3> pathPoints;
private int segments;
public int pointCount;
public BezierPath()
{
pathPoints = new List<Vector3>();
pointCount = 100;
}
public void DeletePath()
{
pathPoints.Clear ();
}
Vector3 BezierPathCalculation(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t)
{
float tt = t * t;
float ttt = t * tt;
float u = 1.0f - t;
float uu = u * u;
float uuu = u * uu;
Vector3 B = new Vector3();
B = uuu * p0;
B += 3.0f * uu * t * p1;
B += 3.0f * u * tt * p2;
B += ttt * p3;
return B;
}
public void CreateCurve(List<Vector3> controlPoints)
{
segments = controlPoints.Count / 3;
for (int s = 0; s < controlPoints.Count -3; s+=3)
{
Vector3 p0 = controlPoints[s];
Vector3 p1 = controlPoints[s+1];
Vector3 p2 = controlPoints[s+2];
Vector3 p3 = controlPoints[s+3];
if(s == 0)
{
pathPoints.Add(BezierPathCalculation(p0, p1, p2, p3, 0.0f));
}
for (int p = 0; p < (pointCount/segments); p++)
{
float t = (1.0f / (pointCount/segments)) * p;
Vector3 point = new Vector3 ();
point = BezierPathCalculation (p0, p1, p2, p3, t);
pathPoints.Add (point);
}
}
}
}
private void createLine(Vector3 start, Vector3 end, float lineSize, Color c)
{
GameObject canvas = new GameObject("canvas" + canvasIndex);
canvas.transform.parent = transform;
canvas.transform.rotation = transform.rotation;
LineRenderer lines = (LineRenderer) canvas.AddComponent<LineRenderer>();
lines.material = new Material(shader);
lines.material.color = c;
lines.useWorldSpace = false;
lines.SetWidth(lineSize, lineSize);
lines.SetVertexCount(2);
lines.SetPosition(0, start);
lines.SetPosition(1, end);
canvasIndex++;
}
private void UpdatePath()
{
List<Vector3> c = new List<Vector3>();
for(int o = 0; o < objects.Length; o++)
{
if(objects[o] != null)
{
Vector3 p = objects[o].transform.position;
c.Add (p);
}
}
path.DeletePath ();
path.CreateCurve(c);
}
private int canvasIndex = 0;
public Shader shader;
BezierPath path = new BezierPath();
public GameObject[] objects;
// Use this for initialization
void Start () {
UpdatePath ();
}
// Update is called once per frame
void Update ()
{
UpdatePath ();
for (int i = 1; i < (path.pointCount); i++)
{
Vector3 startv = path.pathPoints[i-1];
Vector3 endv = path.pathPoints[i];
createLine (startv, endv, 0.25f, Color.blue);
}
}
void OnDrawGizmos()
{
UpdatePath ();
for (int i = 1; i < (path.pointCount); i++)
{
Vector3 startv = path.pathPoints[i-1];
Vector3 endv = path.pathPoints[i];
Gizmos.color = Color.blue;
Gizmos.DrawLine(startv, endv);
}
}
}
@TheTiki

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@TheTiki TheTiki commented Oct 8, 2015

Compact and readable, of all the scripts I've looked through for unity bezier's this one is my favorite.

@mycodingdad

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@mycodingdad mycodingdad commented Nov 4, 2019

Thank you, afaq125 🙏 This code is really good!

@Khan-amil

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@Khan-amil Khan-amil commented Apr 30, 2020

Bezier drawing is fine, but the overall implementation is pretty terrible.
Do not use it as is in a runtime scenario, creating hundreds of objects and adding components each frame isn't a way to go.

@vadermemo

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@vadermemo vadermemo commented Jul 3, 2020

Bezier drawing is fine, but the overall implementation is pretty terrible.
Do not use it as is in a runtime scenario, creating hundreds of objects and adding components each frame isn't a way to go.

hi friend. What you use instead?

@aeiowu

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@aeiowu aeiowu commented Sep 23, 2020

The madness Khan-amil is talking about lives in the "createLine()" function. There's no reason to create a new GameObject w/ its own LineRender every frame, for every single line segment. LineRenderer can take an array of points and do just fine with them. Just replace that function with

private void CreateLine() 
{
	Vector3[] newPointArray = new Vector3[path.pointCount];
	for(int i = 0; i < newPointArray.Length; i++)
	{
		newPointArray[i] = path.pathPoints[i];
	}

	_lineRenderer.positionCount = newPointArray.Length;
	_lineRenderer.SetPositions(newPointArray);
}

this way you don't have to have a for loop in Start or Update either, you simply call CreateLine() and manage the style of the LineRenderer on a single object in the inspector. Also, don't forget you'll need a LineRenderer object in the constructor of this class and wire it up in Start or Awake with GetComponent...

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