Celestia Forums

I've noticed that some people place a "big" 2048 big tile at level 5 of a virtual texture using 512 tiles. This seems to work, but what if any are the limitations on this. Can any size be used?

I'm asking since I found a nice image I want to insert into my earth VT, but firstly it is too big to fit at even level 10 (the current limit?). Secondly, I'm hoping that I can possibly insert it at a higher level where it will not need to be split into so many tiles (it would be 24 level 10 tiles).

Kolano, the tile size limeted by your graphig card. Look at OpenGl info in Celestia and you will see which tiles your card can handel (texture size). Most cards can use 2048x2048 tiles some newer hardware GF3 and above (not GF4MX) work also with 4096x4096 texture tiles.

Does this help?

Bye Jens

Yes, some. I guess I'm stuck with 2048px tiles then, which means I will definatly need to go down to level 10 .

jim wrote:Kolano, the tile size limeted by your graphig card.

I guess you are right on this since i am not able to use 4096x4096 tiles on my 64 megs graphic card..

In some way it is for the best to use only 2048x2048 tile on Blue marble because 4096x4096 dds files are big to work and for the so big size the result will give..  They are 8,388,736kb each..    

Well, in my point of view, too big for nothing for just a little bit more quality..  Best will be to have level 11 to 15..  But.. hehe, just thinking to calculate the tx_numbers for these higher level, will be a pain..  Well if ever this option comes out, i will surely try it but only 1 time..

J.P.

I'm in an even worse position, I can't even handle 2048 textures, it's 1024 maximum for me. So I've been manually cutting the 2k ones in 4 and dropping them down a level, then resizing the 'top-level' ones. Takes ages.

Question: can the zoom/proximity at which celestia 'jumps' up to the next VT level be tweaked in any way? Wouldn't *that* be preferrable to manufacturing tiles of different sizes in order to optimize resolution? It'd certainly make things more accessible for people stuck on legacy hardware if there were a standard, user-friendly tile-size and the well-equipped user just cranked up the in-client 'VT detail level' or whatever. Mucking around with mixed tile-sizes seems a crude way to go about it.

Anyway, I'm only on a 16meg generic graphics card, stuck using jpg tiles, and they still look GREAT. I've played around with them up to level 11 using 1024 tiles and it all runs smoothly. That's the beauty of VTs, people stuck with poor hardware get to say 'I see my house from here' as well. Some sort of standardization would be a big plus though.

Celestia switches to the next level sooner if you lie to it and say that the tiles are smaller. e.g. specify a size of 128.

I'm guessing that level 10 is the current limit because of the number of divisions Celestia uses to simulate a sphere: tiles at level10 are scaled to exactly fill one surface face. To get better resolution with small tiles, Celestia would have to subdivide the model more -- which would use more graphics memory and cause a slowdown for some operations.

I think the number of divisions used for a spherical model should be an option in celestia.cfg, accompanied by appropriate warnings, of course.