unity 貝塞爾曲線的製作
阿新 • • 發佈:2019-01-31
通過傳入Vector3[]值,返回座標點陣列
public Vector3[] CreatPath(Vector3[] path,int SmoothSens) { Vector3[] vector3s = PathControlPointGenerator(path); Vector3 prevPt = Interp(vector3s, 0); int SmoothAmount = path.Length * SmoothSens; Vector3[] positons = new Vector3[SmoothAmount]; for (int i = 1; i <= SmoothAmount; i++) { float pm = (float)i / SmoothAmount; Vector3 currPt = Interp(vector3s, pm); positons[i - 1] = currPt; if (i != SmoothAmount) { positons[i] = prevPt; } prevPt = currPt; } return positons; } private Vector3[] PathControlPointGenerator(Vector3[] path) { Vector3[] suppliedPath; Vector3[] vector3s; //create and store path points: suppliedPath = path; //populate calculate path; int offset = 2; vector3s = new Vector3[suppliedPath.Length + offset]; Array.Copy(suppliedPath, 0, vector3s, 1, suppliedPath.Length); //populate start and end control points: //vector3s[0] = vector3s[1] - vector3s[2]; vector3s[0] = vector3s[1] + (vector3s[1] - vector3s[2]); vector3s[vector3s.Length - 1] = vector3s[vector3s.Length - 2] + (vector3s[vector3s.Length - 2] - vector3s[vector3s.Length - 3]); //is this a closed, continuous loop? yes? well then so let's make a continuous Catmull-Rom spline! if (vector3s[1] == vector3s[vector3s.Length - 2]) { Vector3[] tmpLoopSpline = new Vector3[vector3s.Length]; Array.Copy(vector3s, tmpLoopSpline, vector3s.Length); tmpLoopSpline[0] = tmpLoopSpline[tmpLoopSpline.Length - 3]; tmpLoopSpline[tmpLoopSpline.Length - 1] = tmpLoopSpline[2]; vector3s = new Vector3[tmpLoopSpline.Length]; Array.Copy(tmpLoopSpline, vector3s, tmpLoopSpline.Length); } return (vector3s); } public Vector3 Interp(Vector3[] pts, float t) { int numSections = pts.Length - 3; int currPt = Mathf.Min(Mathf.FloorToInt(t * (float)numSections), numSections - 1); float u = t * (float)numSections - (float)currPt; Vector3 a = pts[currPt]; Vector3 b = pts[currPt + 1]; Vector3 c = pts[currPt + 2]; Vector3 d = pts[currPt + 3]; return .5f * ( (-a + 3f * b - 3f * c + d) * (u * u * u) + (2f * a - 5f * b + 4f * c - d) * (u * u) + (-a + c) * u + 2f * b ); }