# Space travel, size, speed and light

Hi all

Was thinking about doing a small starter project in JME3, a model of a solar system that the user can fly around in.

I am not sure how to do the objects in the solar system and how far there should be between them.

For instance. Do I create a huge sun and big planets with a lot of space between them and let the user move really quick. Or create small sun and small planets with not that much space between and let the user move very slow. Moving quick might not be that precise if I wanted to fly close by something. Moving slow might be a problem with space dust.

What about light from the sun, how far can a light that shines in all directions be seen on objects, and what about the shadows the planets cast, can they be correct if the sun is close to the planet.

What do you think would give the best impression of big distances? What would make it look like the user is traveling fast and flying close to a really big sun/planet. Or is this just a trial and error until I find a combination that works. I am pretty sure that I am not the first person considering creating a space simulator/game or something like that.

Best regards

Rasmus

My guess is, that realistic proportions would be BOORING. Dont see almost anything, everything takes long…

The impression is not based on the actual numbers but on the size relations and camera frustum. For the actual values you have to take into account that you are working with 32bit float values and that they get more inaccurate as they get bigger so you will get problems with too big values (dont ask me whats the max size, its totally dependent on what filters, operations etc you use).

So you should scale the world accordingly and maybe even move the player back to the zero position and actually move the world around him when he’s reaching a certain “boundary” so that you can emulate “endless” space.

So no really large distances between objects.

Setting the frustrum to make everything look like it’s far away, would that not distort the view of small objects like asteroids?

Here’s the scenario:

Player is flying around the solar system seeing the sun in the background and maybe a planet not to far away and some asteroids that are just in front of the player. The player is moving slowly around to see the asteroids. So sun far of, not to big on the screen, planet a bit away, but rather big in on the screen and asteroids close by rather big on the screen.

To get the proportions right, the sun needs to be larger than everything else as it is far away and the planet needs to be large as well, right? And the sun needs to be rather far away. Can this be achieved by setting the frustrum or would that mess up the asteroids when the player is moving around them?

I’d rather think about simulating the vary far away planet like a sky, meaning a single quad with an image of the planet that is placed close to the player but drawn behind everything else.

Would still be cool if the entire solar system was there and just looked right, without using billboards “or what they are called in jme”. It’s not like there is going to be a lot of object’s and they are going to be fairly low polly, so it’s not a speed concern.

Maybe I could scale everything so the closer the player get’s the bigger the object get’s. Then the sun stays small until the player get’s within a certain range and then I scale it up as he moves closer. Would eliminate the need for large distances between objects. Might look strange in some instances, but might be worth a try.

Didn’t old space simulators do exactly that? I recall landing on planets in Privateer and they looked pretty darn pixelated by the time the landing sequence would start. Given, back then they were probably using 64x64 images on a billboard so it looked terrible up close so you probably won’t run into this issue

~FlaH