void RemoveTimeOutPoints()
{
List <CatmullRomPoint> toRemoveList = new List <CatmullRomPoint>();
for (var i = 0; i < catmullRomPointList.Count; i++)
{
CatmullRomPoint point = catmullRomPointList[i];
if (Time.realtimeSinceStartup - point.createTime > life_time)
{
toRemoveList.Add(point);
}
}
for (var i = 0; i < toRemoveList.Count; i++)
{
CatmullRomPoint point = toRemoveList[i];
catmullRomPointList.Remove(point);
}
}
public CatmullRomSegment(CatmullRomPoint p0, CatmullRomPoint p1, CatmullRomPoint p2, CatmullRomPoint p3,
int subSegmentNum)
{
this.p0 = p0;
this.p1 = p1;
this.p2 = p2;
this.p3 = p3;
this.subSegmentNum = subSegmentNum;
length = 0;
for (float i = 0; i < subSegmentNum; i++)
{
var point0 = GetPoint(i / subSegmentNum);
var tangent0 = GetTangent(i / subSegmentNum);
var createTime0 = Mathf.Lerp(p2.createTime, p3.createTime, i / subSegmentNum);
var point1 = GetPoint((i + 1) / subSegmentNum);
var tangent1 = GetTangent((i + 1) / subSegmentNum);
var createTime1 = Mathf.Lerp(p2.createTime, p3.createTime, (i + 1) / subSegmentNum);
var segment = new Segment(new Knot(point0, tangent0, createTime0), new Knot(point1, tangent1, createTime1));
subSegmentList.Add(segment);
length += segment.length;
}
}
public CatmullRomSpline(CatmullRomPoint[] orgPoints, int subSegmentNum)
{
segment_num = orgPoints.Length - 1;
//添加头尾顺延曲线方向的两个点
var list = new List <CatmullRomPoint>(orgPoints);
var first = new CatmullRomPoint(2 * orgPoints[0].position - orgPoints[1].position,
orgPoints[0].createTime);
var last = new CatmullRomPoint(
2 * orgPoints[orgPoints.Length - 1].position - orgPoints[orgPoints.Length - 2].position,
orgPoints[orgPoints.Length - 1].createTime);
list.Insert(0, first);
list.Add(last);
this.orgPoints = list.ToArray();
length = 0;
for (var i = 1; i <= this.orgPoints.Length - 3; i++)
{
segmentList.Add(new CatmullRomSegment(this.orgPoints[i - 1], this.orgPoints[i], this.orgPoints[i + 1],
this.orgPoints[i + 2], subSegmentNum));
length += segmentList[segmentList.Count - 1].length;
}
}
void Update()
{
Vector3 currentPoint = this.transform.position;
bool isNeedAddPoint = false;
if (catmullRomPointList.Count < 2)
{
isNeedAddPoint = true;
}
else
{
float vertexDistance =
(currentPoint - catmullRomPointList[catmullRomPointList.Count - 2].position).magnitude;
if (vertexDistance > emissionDistance)
{
isNeedAddPoint = true;
}
}
if (isNeedAddPoint)
{
catmullRomPoint = new CatmullRomPoint(currentPoint, Time.realtimeSinceStartup);
catmullRomPointList.Add(catmullRomPoint);
}
else
{
catmullRomPoint = catmullRomPointList[catmullRomPointList.Count - 1];
catmullRomPoint.position = currentPoint;
catmullRomPoint.createTime = Time.realtimeSinceStartup;
}
RemoveTimeOutPoints();
if (catmullRomPointList.Count < 2)
{
catmullRomMesh.Clear();
return;
}
CatmullRomPoint[] catmullRomPoints = catmullRomPointList.ToArray();
catmullRomPoints.Reverse();
spline = new CatmullRomSpline(catmullRomPoints, subdivision);
newVerticeList.Clear();
newUVList.Clear();
newTriangleList.Clear();
//float splineLength = Mathf.Max(0, spline.GetLength()-0.1f);
float splineLength = Mathf.Max(0, spline.length);
int n = 0;
bool isAngleDiffBig = false; //用于合并，当角度相差太大的时候，不进行合并
float eachAddDistance = 0.25f * width;
//float eachAddDistance = 0.001f * width;
for (float distance = 0;
distance <= splineLength;
distance = distance + eachAddDistance > splineLength ? splineLength : distance + eachAddDistance)
{
curPoint = spline.GetPointAtDistance(distance);
curTangent = spline.GetTangentAtDistance(distance);
Vector3 biNormal = CatmullRomSpline.ComputeBinormal(curTangent.position, normal);
float timeSpan = Time.realtimeSinceStartup - curPoint.createTime;
float lerpHeight = height;
//合并相邻两个切线率相差不多的segment
// if (n > 1)
// {
// float lastDistance = distance - width;
// lastTangent = spline.GetTangentAtDistance(lastDistance);
// float angle = Vector3.Angle(lastTangent.position, curTangent.position);
// if (angle <= 0.5f)
// {
// if (!isAngleDiffBig)
// {
// for (int i = 0; i < 2; i++)
// {
// newVerticeList.RemoveLast();
// newUVList.RemoveLast();
// }
// for (int i = 0; i < 6; i++)
// newTriangleList.RemoveLast();
// n--;
// }
// else
// isAngleDiffBig = false;
// }
// else
// {
// isAngleDiffBig = true;
// }
// }
//需要添加epsilonAdd细小的offset，才能显示在mobile手机上，手机上刚好的在摄像机的nearClipPlane上是显示不出来的
Vector3 epsilonAdd = camera.transform.forward * epsilon;
newVerticeList.Add(curPoint.position - (biNormal * (lerpHeight * 0.5f)) + epsilonAdd);
newVerticeList.Add(curPoint.position + (biNormal * (lerpHeight * 0.5f)) + epsilonAdd);
float lerp = 0;
if (splineLength < width) //少于width的用正常lerp
{
lerp = distance / splineLength;
}
else //大于width的时候特殊处理
{
if (distance <= 0.5f * width) //少于0.5f * width的部分占全图片的50%
{
lerp = 0.5f * (distance / (0.5f * width));
}
else //线段的其他部分平分剩下图片的50%
{
lerp = 0.5f + 0.5f * ((distance - 0.5f * width) / (splineLength - 0.5f * width));
}
}
newUVList.Add(new Vector2(lerp, 0));
newUVList.Add(new Vector2(lerp, 1));
if (n > 0)
{
newTriangleList.Add((n * 2) - 2);
newTriangleList.Add((n * 2) - 1);
newTriangleList.Add(n * 2);
newTriangleList.Add((n * 2) + 1);
newTriangleList.Add(n * 2);
newTriangleList.Add((n * 2) - 1);
}
if (distance >= splineLength - dd)
{
break;
}
if (distance == splineLength)
{
break;
}
n++;
}
catmullRomMesh.Clear();
catmullRomMesh.vertices = newVerticeList.ToArray();
catmullRomMesh.uv = newUVList.ToArray();
catmullRomMesh.triangles = newTriangleList.ToArray();
}
