Hi there, I am a bit of a noob with all the terminology around this subject so I am just going to spell out exactly what I am trying to do and any advice or tips are very welcome.

The Plan:
I have created some software for simulating the flight path of hobby rockets which is being released soon as a tool box for Octave: http://cambridgerocket.sourceforge.net/

But now I want to turn it into a stand-alone program. So I have written the core simulation part in C++ and it works great but it just produces lots of numbers and I need to visualize them.

So I want my program to output 2D and 3D scatter and line plots of flight paths after a simulation. So I guess I need a library for c++ or another language is fine too (e.g. Java), but it must be open source.

Help please!:
I am quite new to all this and web searches are just bamboozling me with terms like OpenGL VTK etc none of which I fully understand. If you have any tips for good libraries or resources that can help me learn more please let me know! Thanks.