/*!
* @param world Vixen 3D world
* Initializes the Vixen 3D environment for the given world.
* If you do not provide an initial world, one is created for you.
* This function does not start 3D display - RunVixen does that.
* The world can only be initialized once - subsequent calls do nothing.
*
* @return -> Vixen SharedWorld or null if initialization failed
*/
static public SharedWorld StartVixen(SharedWorld world)
{
_world = world;
if (_world == null)
{
_world = new Viewer3D();
}
else if (_world.FileName != null)
{
string dir = Path.GetDirectoryName(_world.FileName);
if ((dir != null) && (dir.Length > 0))
{
Directory.SetCurrentDirectory(dir);
_world.SetMediaDir(dir);
}
}
if ((_world == null) || !_world.OnInit())
{
SharedWorld.LogError("cannot initialize Vixen");
return(null);
}
GC.KeepAlive(_world);
_world.MakeLock();
if (UsePhysics)
{
Physics.Startup();
}
return(_world);
}