Celestia Forums

I hav Microsoft Combat Flight Simulator II.
Thay all use small bmp files that flight simulator stiches together to make the ground, in Microsoft Combat Flight Simulator II the ground is all flat, in the new one it is streched over lots of 3d meshes stiched together under the bmp files, so I figur that if I, or someone els with Microsoft Combat Flight Simulator II can stich tem togeher to make a verry high res textur we will be able to look at earth from only 100ft and still hav a grate pictur quality.
Will this work, or will it bog down even my brand new GForce FX 5900?

I don't think it will work. Game graphic textures are usually not of very high quality. Sure they look good in the game but when it counts they probably are not at the level Blue-Marbles textures are. Besides if they are that good where do you think they got them from. Most likely from NASA and that leads right back to Blue-Marble. Microsoft doesn't own any planetary imaging satellites as far as I know. Another thing is if they were so high resolution you should be running into the same problems we do with Celestia. These high graphics even broken down into a game would make the playability slow. When you are playing a game like a flight simulator you really do not have that much time to view the terrain as things are usually moving around. So how could anyone ever really get a real good idea of just how good those textures are through all the other effects going on?
I think what you are seeing in the game is some programmed terrain generation based on known topographical info and low resolution textures painted over the terrain. I have played a few games that had very good wow-wee graphics but when I compare a screenshot along side Celestia there just is no comparing them.
Chris is working on a tiling engine for big graphics but its still a ways off. I am not sure how it works but it should be able to take a 32k texture and break it down into pieces that are only used for the area you are viewing to increase detail at low elevations. A high resolution texture has no use above a certain point. The whole reason the screenshots of my new 16k texture are all for the most part at the limit of the texture before they go blurry is for that reason alone.
Also Celestia really and truly was never made to give us a ground view or a planets surface view. It has evolved in that direction somewhat. I don't have a problem with that but even with texture tiling we are not going to get the effects you are speaking of. It would involve building in a surface terrain generator and Celestia would have to hand off the rendering to this engine at the right time. I am not saying its not possible but for now this is just that important. Celestia is supposed to be a Space-Simulator not a planet simulator. I think expanding Celestia's ability to render more of the galaxy and other astro-physical objects is more important at this time. After that then we can start thinking of taking the user to the surface of other worlds. We must remember what Celestia is all about in the first place. If we want a planet simulator then someone should use the source code and fork the project in that direction with Chris' blessing of course.
This is just my thoughts on this. No one has to agree with me. But I feel we are trying to hard to push Celestia in one direction when it should be going the other way. Sure big beautiful textures are great and they have there place. Why else would I make them. But in reality Celestia is bigger than this and I hope we all keep this in mind.

Don.

!! WHAT DO YOU MEEN NOT HI QUALITY !!

Each small bmp is a 512 x 512 pixil 256 color squair, and each covers at least 1 squair mile "not shur if this is right, if not 1 squair mile than 4" and the picturs that I hav stiched togeter are so good you can see streets and rivers, not to menchion houses and even dockes in the harbors "this isent even in the game, I am looking at thees in microsoft paint, or microsoft photo editor"

wait...

Ok I used a program to stich the hundreds of bmp files, and it's got to be like a 128, or 256k textur "I cant tell but my FX Vidio card is choking on it", its over a gig, I might convert it to jpg, because I dont no how to convert to dds "by the way wich one would be smaller?"

wait...

Ok that took a longer time than I thot, but it's still over a gig, but it is smaller "over 100 mb smaller" And my GForce FX isstill choking on it in celestia
When it loads it gets to earth "after a half houer" and it looks grate, at a full 0.0000001 frames per second "more or less" and after about 5 minits of looking at it in all of its glory the overheat light comes on for my GForce FX, and my system shuts down, and I halfto wait for it to kool down so I can turn it back on.
You were right about the high res textur at long range "exept that the big one I put together looks a littil undersaturated compaird to what I am used to with the 16k textur" but when you get like 500ft you can see everything "the only way I got there was editing the file that tells where to start to make it start and end at the 500ft altitud" but its so sloe that it isent worth it

P.S. sorry for my english

The game could be using the data from NVidia's world simulator. It too was able to let you zoom in quiet close to areas of the Earth. But it had very big holes were there was no data. At the resolution you are talking the texture would be so big that a video card with 2Gigs of VRAM might not be enough. We have to come to the decision as to were to cut off texture size. Right now the cut-off is 16k. I know DBrady made a 32k texture but it is going to take a 256Mb video card to render the thing quickly enough for everyone to enjoy it. Most users do not have cards like that as of yet. And even if everybody did have 256Mb cards Celestia just isn't ready for massive textures at this time. Maybe when we all move to the PCI Express Bus for video we will loose part of the bottle-neck. But right now the bigger the textures the slower things get.
Again it’s the whole thing about what Celestia is all about. As I said Celestia is a space simulator not a planetary surface simulator. Sure it does a pretty good job of rendering the surface of a planet from above 1000 meters. But below that it starts to get to be a blurry mess. And it is not what Chris made Celestia for in the first place. That’s why I feel there needs to be a dividing line drawn. If you want detail that looks like you are standing on the surface than use another program or build one. But leave Celestia to do what it does best. Simulate space. Chris has done a great job so far but people asking for surface detail is just going to slow down other areas of the project that need tending. Again this is my personal opinion but I am sure other will agree and still other will disagree. Please keep in mind that Celestia is a relatively small program. Building in those other features is going to create bloating. I like it lean and mean. If I want to render another planet's surface I will go and play in Bryce 5 or Terragen.

Don.

You guys are all making incorrect assumptions of how textures are used in games. The textures in MS CFS III (and definitely those before) are not specifically based on imaging of the Earth. Using a Blue-Marble type texture, for instance, would be very inefficient for the requirements of a game.

The textures are most definitely small-ish squares that represent types of terrain. There's a grass texture, a sand texture, a water texture, a pavement texture, etc. These textures are tiled, one on top of another, to build up the look of the terrain in the game. The size of the textures is chosen to optimize the use of the video card's memory. Current games are probably not using textures larger than 512x512.

The actual geometry of the landscape is probably derived from some real elevation data but not likely at a very high resolution. The high detail seen in-game is interpolated from the real samples to make it look good.

The accuracy of the visuals in flight sims is not constant. More resources are spent trying to get the layout of cities and famous landmarks as close to real as possible. The rest of the terrain is just classified as fields or deserts or ocean. The textures for those areas are stitched together in such a way as to be most aesthetically pleasing.

Celestia doesn't work this way and I don't think it's the direction that Chris wants to go. Least of all, it would make creating textures for planets much more complicated as you would not only have to create the "component" textures, but then specify how they're stitched together. Not feasable.

EarthViewer, Don, does not store the textures on the client machine. You need an internet connection to use the program because the very high resolution images are downloaded as needed. They probably have terabytes of near-military grade textures in their database, but you only get the data for a city at a time.

Star Lion, I have no clue what you're talking about...

- a b i o g e n e s i s -

-I doubt it would work...but CFS2/FS2002 has very nice graphics indeed.
-CFS2/FS2002 uses a landclass map to decide what to put where. Mesh is added rather than bumpmaps to give 3D terrain. Overall...an extremely accurate map of the entire planet.
-CFS2/FS2002's map is actually a cylindrical projection...no poles.

...you can go up to about 70 deg N or S before weirdness takes over.
-If you have never had the pleasure...here's some screenies.

F-86A Sabre over a midwest US city...not sure which one.
A B-24J near Bora Bora French Polynesia.
A B-29A near Los Angeles


Cheers,
Rolf