"""
Lotka Volterra Attraktor
(c) Juergen Meier (www.3d-meier.de)
24.12.2021
"""

import c4d
import math

def CreateSplineObject():
  # Variablen und Konstanten
    Name = "Lotka Volterra Attractor"
    a = 2.9851         # Konstante Lotka Volterra Attraktor
    b = 3              # Konstante Lotka Volterra Attraktor
    c = 2              # Konstante Lotka Volterra Attraktor
    x0 = 1.0           # Startwerte
    y0 = 1.0           # Startwerte
    z0 = 1.0           # Startwerte
    Delta = 0.01       # Delta Wert fuer die Berechnung
    N = 20000          # Anzahl Punkte
    Faktor = 1000      # Skalierungsfaktor
    x = x0             # Startwerte zuweisen
    y = y0             # Startwerte zuweisen
    z = z0             # Startwerte zuweisen

    obj = c4d.BaseObject(c4d.Ospline)       # Splineobjekt erzeugen
    obj.ResizeObject(N)                     # Groesse des Spline festlegen
    obj[c4d.SPLINEOBJECT_CLOSED] = False
    #obj[c4d.SPLINEOBJECT_TYPE] = c4d.SPLINETYPE_LINEAR
    obj[c4d.SPLINEOBJECT_TYPE] = c4d.SPLINETYPE_BSPLINE
    #obj[c4d.SPLINEOBJECT_TYPE] = c4d.SPLINETYPE_BEZIER
    obj.SetName(Name)


    for i in range(0,N):
       dx=x-x*y+c*x*x-a*z*x*x
       dy=-y+x*y
       dz=-b*z+a*z*x*x
       x=x + Delta * dx
       y=y + Delta * dy
       z=z + Delta * dz
       obj.SetPoint(i, c4d.Vector(x*Faktor, y*Faktor, z*Faktor))

    obj.Message(c4d.MSG_UPDATE)
    return obj

def main():
    slinobj = CreateSplineObject()

    doc.InsertObject(slinobj, None, None, True)

    c4d.EventAdd()

if __name__=='__main__':
    main()