/**
     * Handle initial setup for the vector field
     */
    public void StartVectorField()
    {
        vectorField.LoadFromFile(tilemap);

        // if flag set or the vector field doesn't match the tilemap, clear the vector field
        if (clearFieldOnStart || !vectorField.VectorFieldMatches(tilemap))
        {
            vectorField.ResetVectorField(tilemap);
        }
    }