Re: [cgkit-user] cgkit and Hydraulic cylinder model

[Matthias B. <mat...@gm...>]

Myrek wrote:
> Yes, I want to do a dynamics simulation. So I have to make a model in an 
> external (different) programm, after I have to export it as obj file (*.obj) 
> and I'll import it to my program which I have written in Python?

Yes, if the existing geometric primitives are not adequate for your 
model then you need to create your own models (which are eventually 
turned into triangle meshes).
But keep in mind that the geometry is actually only required for two 
things: determining mass properties and collision detection.
And whenever possible you should avoid using triangle meshes for 
collision detection. The other primitives are faster and more stable.
Depending on what you want to do you may even get away without any 
collision detection at all and just using appropriate joints to connect 
the parts together.

> I need to use cgkit + ODE to move him. In addition, hydraulic cylinder has 
> to move after entering the proper tilt in the window written (or moving the 
> slider) in Python (wxPython). Is this feasible?

If you want to use GUI elements (slider, buttons, etc.) you can write 
your own wxPython application that contains an OpenGL window and draw 
the cgkit scene into that window.

> How do make interactive window in Python, which will appear in a scene? 
> Should I use somehow the viewer.py? Or should I use something different?

The viewer tool is rather a simple visualization tool. It doesn't allow 
you to create GUI controls though. It can be extended to allow selecting 
3D objects but for any other GUI stuff you need to write your own 
"viewer" tool. All you need is an OpenGL widget that can be used to draw 
the cgkit scene (have a look into the viewer tool to see how it draws 
the scene).

> Later, I would like to steer this hydraulic cylinder with microcontroller 
> connected to a computer via the RS-232 port

Of course, that leaves the scope of cgkit and you need an appropriate 
library to read those values. Maybe PySerial could be useful here 
(http://pyserial.sourceforge.net/).

- Matthias -