alexus37 / asteroidField

A n-body simulation with collision detection https://www.youtube.com/watch?v=qUCG8pPnXn4&feature=youtu.be

Project: Asteroid Fields

Getting Started

Prerequisites

Open Scene Graph (OSG, Version > 3.2.1)

Windows:

• Download the libraries of OSG from here: http://objexx.com/OpenSceneGraph.html (debug and release if you want to build in both)
• Extract to <path_to_osg>/ (I pasted release and debug in the same, since they use a "d" as postfix for each files => no problems with overwritting etc)
• Add path <path_to_osg>/bin to the PATH-environment-variable

Ubuntu:

• Install the libraries with "sudo apt-get install openscenegraph libopenscenegraph-dev libopenscenegraph100v5"
• For the examples one can use "sudo apt-get install openscenegraph-examples". These can then simply called by the command "osgteapot" for example.
• Includes should be at "/usr/include" and libraries at /usr/lib/x86_64-linux-gnu (at least for me.. ;-) )

Boost (Version > 1.54)

Windows:

• Instructions: http://www.boost.org/doc/libs/1_65_1/more/getting_started/windows.html
• Set environment-variable BOOST_ROOT to <path_to_boost>

Ubuntu:

• Instructions: http://www.boost.org/doc/libs/1_65_1/more/getting_started/unix-variants.html
• Install the libraries with "sudo apt-get install libboost*" (except you know which you really need ;-) )

CGAL (Version 4.12-I-900 - Install from git-source)

Windows:

• Instructions: https://www.cgal.org/download/windows.html
• Download the installer CGAL-4.11-Setup.exe from here: https://github.com/CGAL/cgal/releases
• Install it to <path_to_cgal>
• Set environment-variable CGAL_DIR to <path_to_cgal>
• Add <path_to_cgal>\auxiliary\gmp\lib to the PATH-environment-variable

Ubuntu:

• Instructions: https://www.cgal.org/download/linux.html
• Install the libraries with "sudo apt-get install libcgal*"
• If this works, fine, otherwise:
  • Download the source from git to <path_to_cgal>
  • Build it with make install in <path_to_cgal>/build

Project-setup

I suggest to use the cmake-gui, since it most likely does not find the variables autoamtically, so it might be easier to set them correctly.

• Specify the location for source to "physSim/project/code" and for binaries to "physSim/project/code/build".
• Hit configure (Windows => make sure to select 64Bit-version)
• Verify or set these variables:
  • OPENSCENEGRAPH_INCLUDE_DIR:
    • Windows: <path_to_osg>/include
    • Ubuntu: /usr/include
  • OPENSCENEGRAPH_LIB_DIR:
    • Windows: <path_to_osg>/lib
    • Ubuntu: /usr/lib/x86_64-linux-gnu (for me)
  • BOOST_INCLUDE_DIR: (acvanced, when found => Boost version: 1.65.1 Boost_FOUND=true. is written in the output of cmake)
    • Windows: <path_to_boost>
    • Ubunutu: /usr/include
  • CGAL_DIR:
    • Windows: <path_to_cgal>/build
    • Ubuntu: <path_to_cgal>/build
• Generate

Open the project, build and run it and enjoy :-) Verify that the path to the models in "config.h" is set to the correct folder (should already, but you never know).

Structure

I added two asteroid (3d obj models) and two planets (simple spheres). Both implemented in the classes Asteroid, and Planet respectively. So far it is really basic and I will continue with working on the look and feel of the whole scene => nicer background than violet and so on :-)

The structure is meant to be like this:

• Core: main loop, path config, ...
• Graphics: All graphics calculations (convex-hull, minkowski-sum, ...)
• OSG: Using and setup of OSG. All rendering-relevant parts are included here as well classes to work with OSG.
• OSG/Visitors: All visitors which are used for OSG to traverse the graph to make calculations/changes on the nodes
• Physics: All physics calculations (Collision-handling, NBody-handling, ...)
• Scene: Used to build and manage the scene and the objects which are currently on the scene.