[CINEMA 4D: Python Set Global Axis Rotation Func] A function for setting the orientation of the object axis withouth modifying the points. #cinema4d #c4d #python #function #computergraphics #cg

C4D-SetGlobalAxisRotation.py

def SetGlobalAxisRotation(obj, rot, depth=0):
    """
    Set the global rotation of the object axis (i.e. keeping points in place).
    
    obj   object
    rot   vector
    """
    # unfortunately tail recursion and depth guard 
    # seem needed because of the MatrixToHPB(HPBToMatrix(Rad(angle)) 
    # roundtrip round-off error, so we need to improve
    # our solution with each recursion level
    depth += 1
    if obj is None: return False
    if not isinstance(rot, c4d.Vector):
        raise TypeError("expected c4d.Vector, got %s" % type(rot))
    mg = obj.GetMg()
    # calc difference to current orientation 
    # (we want absolute value opposed to relative increment)
    currot = MatrixToHPB(obj.GetMg())
    diff = rot-currot
    if VectorEqual(rot, currot) or depth >= 50:
        return False
    else:
        if DEBUG:
            print "%d: rot = %s, currot = %s, diff = %s" % (depth, rot, currot, diff)
        mat = HPBToMatrix(diff)
        print "mat = %s" % (mat)
        # orient whole object (axis + points)
        obj.SetMg(mg * mat)
        # get inverse rotation matrix for the points
        pntsrm = mat.__invert__()
        allpnts = obj.GetAllPoints()
        newpnts = []
        for pnt in allpnts:
            # write back points to previous positions 
            # by applying the inverse matrix
            newpnts.append(pntsrm * pnt)
        obj.SetAllPoints(newpnts)
        obj.Message(c4d.MSG_UPDATE)
        if DEBUG:
            currot = MatrixToHPB(op.GetMg())
            diff = rot-currot
            print "%d: rot = %s, currot = %s, diff = %s" % (depth, rot, currot, diff)
        return SetGlobalAxisRotation(obj, rot, depth)