Quote: "-I know how to create and move a spaceship in 3d world. I just want help for know if it is better to limit the game world and how I can make this"
this question should be quit oposite. Its not problem to make game world limited, its problem to make it unlimited. Only way hove to make it unlimited is to include some level of randomization. All other forms of creating world will by neceserly limited.
Quote: "-I want to create a enemy radar for see where enemys are! I don't know how make this."
make simple plain object and place it on screen where you want to have it. Lock object on screen (there is comnand for that)
make texture for your plain object via 2D comands like
box or
dot -make black box of your radar size (backround) make green dot at the center (your ship), place red dots (enemyes) relatively to their real position in space and distance to your ship -you have to have scale of your radar in mind when placing them on place. Make texture using get image command. Texture your plain object with image. You can fade your plain object that you can see through it.
-voala ...you have your radar. -Its just simple example and ist only 2D radar. Its up to your fantasy to make something diferent and better. Possibilities are nearly unlimited.
Quote: "-and the last but not the least, I want make a beautiful world (star, galaxy, palnet, etc). I kown how to load a bmp file or create a sphere (with texture). I just want an help for know how to make the better beautiful world."
-that depend only on your programing and graphical skills brother