SystemContainer

The SystemContainer is the top level of structures in Exudyn. The container holds all (multibody) systems, solvers and all other data structures for computation. A SystemContainer is created by SC = exu.SystemContainer(), understanding exu.SystemContainer as a class like Python’s internal list class, creating a list instance with x=list(). Currently, only one container shall be used. In future, multiple containers might be usable at the same time. Regarding the (basic) module access, functions are related to the exudyn = exu module, see also the introduction of this chapter and this example:

1import exudyn as exu
2#create system container and store by reference in SC:
3SC = exu.SystemContainer()
4#add MainSystem to SC:
5mbs = SC.AddSystem()

The class SystemContainer has the following functions and structures:

  • Reset():
    delete all multibody systems and reset SystemContainer (including graphics); this also releases SystemContainer from the renderer, which requires SC.AttachToRenderEngine() to be called in order to reconnect to rendering; a safer way is to delete the current SystemContainer and create a new one (SC=SystemContainer() )
  • AddSystem():
    add a new computational system
  • Append(mainSystem):
    append an exsiting computational system to the system container; returns the number of MainSystem in system container
  • NumberOfSystems():
    obtain number of multibody systems available in system container
  • GetSystem(systemNumber):
    obtain multibody systems with index from system container
  • visualizationSettings:
    this structure is read/writeable and contains visualization settings, which are immediately applied to the rendering window.
    EXAMPLE:
    SC = exu.SystemContainer()
    SC.visualizationSettings.autoFitScene=False
  • GetDictionary():
    [UNDER DEVELOPMENT]: return the dictionary of the system container data, e.g., to copy the system or for pickling
  • SetDictionary(systemDict):
    [UNDER DEVELOPMENT]: set system container data from given dictionary; used for pickling
  • GetRenderState():
    Get dictionary with current render state (openGL zoom, modelview, etc.); will have no effect if GLFW_GRAPHICS is deactivated
    Example:
    SC = exu.SystemContainer()
renderState = SC.GetRenderState()
print(renderState['zoom'])
  • SetRenderState(renderState):
    Set current render state (openGL zoom, modelview, etc.) with given dictionary; usually, this dictionary has been obtained with GetRenderState; will have no effect if GLFW_GRAPHICS is deactivated
    Example:
    SC = exu.SystemContainer()
SC.SetRenderState(renderState)
  • RedrawAndSaveImage():
    Redraw openGL scene and save image (command waits until process is finished)
  • WaitForRenderEngineStopFlag():
    Wait for user to stop render engine (Press ‘Q’ or Escape-key); this command is used to have active response of the render window, e.g., to open the visualization dialog or use the right-mouse-button; behaves similar as mbs.WaitForUserToContinue()
  • RenderEngineZoomAll():
    Send zoom all signal, which will perform zoom all at next redraw request
  • AttachToRenderEngine():
    Links the SystemContainer to the render engine, such that the changes in the graphics structure drawn upon updates, etc.; done automatically on creation of SystemContainer; return False, if no renderer exists (e.g., compiled without GLFW) or cannot be linked (if other SystemContainer already linked)
  • DetachFromRenderEngine():
    Releases the SystemContainer from the render engine; return True if successfully released, False if no GLFW available or detaching failed
  • SendRedrawSignal():
    This function is used to send a signal to the renderer that all MainSystems (mbs) shall be redrawn
  • GetCurrentMouseCoordinates(useOpenGLcoordinates = False):
    Get current mouse coordinates as list [x, y]; x and y being floats, as returned by GLFW, measured from top left corner of window; use GetCurrentMouseCoordinates(useOpenGLcoordinates=True) to obtain OpenGLcoordinates of projected plane