adicione as propriedade <summary>, <param>, e <returns> a função;

public static Vector3 BezierSpline(Vector3[] pts, float pm)
    {
        float rawParam = pm * pts.Length;
        int currLeg = Mathf.Clamp(Mathf.FloorToInt(rawParam), 0, pts.Length - 1);
        float t = rawParam - currLeg;

        Vector3 st;
        Vector3 en;
        Vector3 ctrl;

        if (currLeg == 0)
        {
            st = pts[0];
            en = (pts[1] + pts[0]) * 0.5f;
            return Vector3.Lerp(st, en, t);
        }
        else if (currLeg == (pts.Length - 1))
        {
            int pBound = pts.Length - 1;
            st = (pts[pBound - 1] + pts[pBound]) * 0.5f;
            en = pts[pBound];
            return Vector3.Lerp(st, en, t);
        }
        else
        {
            st = (pts[currLeg - 1] + pts[currLeg]) * 0.5f;
            en = (pts[currLeg + 1] + pts[currLeg]) * 0.5f;
            ctrl = pts[currLeg];
            return BezInterp(st, en, ctrl, t);
        }
    }