What is a bump map?

[Polchei]

What does the bump map do on the other planets? I can see how on earth the night city lights go on, but on the other planets I don't see anything on them that requires a bump map.

[granthutchison]

A bump map has nothing to do with city lights - it is a grey-scale image that tells Celestia to simulate bumpy terrain, putting high ground where the map is palest, and low ground where the map is darkest.
Open the mars bump map in an image editor and you should be able to see how this works.

Grant

[Don. Edwards]

Yes Grant is right and since when was Mars declared flat land for that matter. There are many planets in our solar system that can use a bumpmap or a normal map. Mars has the highest mountain in the solar system and the deepest canyons. So these should be viewed as flat? I think not. Bumpmaping has a place with many of the moons of Jupiter and Jupiter itself can use a bumpmap to give the clouds a sense of depth. Next he will be questioning the use of 3DS files for asteroids and comets.

It is sounding to me like Polchei may be a ringer for a competing software program that is more 2D based in its makeup and just can't see the potential for the use of a true 3D engine to view the universe.

So what is going Polchei? Why all the strange questions about Celestia and why it does things the way it does? I think my points and questions are valid don’t you?

Don. Edwards

[selden]

StarStrider has some features that Celestia doesn't, and Celestia has some that StarStrider doesn't. It's just a matter of where the programmers have been spending their efforts.

This includes the availability of "real" 3D deep space objects. All it takes is someone with the time, ability and desire to create them.

Certainly there are some defects in the way Celestia currently draws them, but that shouldn't keep people from creating the ones they want. Eventually I'm sure those limitations will be repaired.