texture advice

[dONKEY]

Am looking for a little advice.
My texture editing and photography skills are improving but there are a couple of (maybe obvious) questions that I have come across.

Most 'modern' Q3 maps that make use of high resolution textures use an image pixel to game pixel ratio of 0.25. Looking at Sock's latest texture set, which basically are 1024 x 1024 texture sheets, are these used with a 0.25 ratio or a 0.125?
I have been experimenting with 1024 x 1024 textures in game at 0.125 and 512 x 512 at 0.25, tbh I can't see a difference, and the obvious pay off is smaller file size.

Apart from a reduction in pk size is there a potential problem with using 1024 sized images at 0.125 (like maximum texture memory)? Or is it generally accepted that a good quality texture remains a good quality texture whether reduced in size in a paint app or in radiant?

Does the use of texture sheets have an significant value to Q3 mapping?

Sorry if these are simple or stupid questions.

[obsidian]

I think a 0.25 value is pretty good for normal use, offering the best balance between resolution and memory performance. As you said, 0.125 may look slightly better if your player's face is pushed up against a wall, but it's hard to tell otherwise and the tradeoffs may start to become significant on some older systems. Quake 3 like most games, makes use of texture mipmapping, so excessively high resolutions aren't really noticeable after a certain distance. I don't think Q3 has a hard coded limit on texture memory, but video cards certainly have a physical limit in how much memory it has built on-board. Modern cards have more than Q3 can practically use, but you should design textures considering slightly older systems.

Q3 isn't very efficient with texture memory usage either. It basically loads as many textures as it can and if need be, swaps without pre-caching. If it ever needs to swap textures, you'll see a huge framerate drop. Most modern games makes use of the enormous texture memory pipelines on the GPU to intelligently pre-cache whatever is currently needed. This process can be a little CPU intensive if there are many many small files, but better optimized if there are fewer large files. To optimize this, modern day engines makes use of batching textures together as larger texture sheets so that it can send out larger files at a time to save CPU cycles. That said, Q3 makes absolutely no use of this feature, so texture sheets aren't particularly useful for Q3 beyond aggravating the person trying to align a texture on a sheet with level geometry. sock is probably used to doing this by now as part of his day job, but it's really unnecessary here.

Summary: 0.25 looks good, Q3 is old and doesn't have any benefits from using texture sheets.

[sock]

I created my industrial texture set at 1024x1024 because it is easier to scale down on detail than go upwards in size and have blurry results. If people want to use 512 then they can, but if they want more detail for close up stuff they have the choice of higher resolution. The same with the batching of all the textures together into large sheets, I personally find it easier and flexible for changing styles. Texture sheets are easier to model with and work much better with modern engines.

For Q3 the best texture density is 0.25 and to cut up the texture how *you* best use them.

[Eraser]

I always thought Q3 used a texture scale of .5? (2 texture pixels translating to 1 unit in-game). At least, 0.5 is the default value for h scale and v scale.

[dONKEY]

It is, but you can change the default texture density. Using higher resolution images and a lower value gives much better results.

[Kat]

I'm with Eraser... you want to stick with the default of 0.5 and only change that relative to the player planting their face up to the wall (easily accessible areas - the inverse is also true, why waste a 1024 on something that only appear onscreen a dozen or so pixels in size). Textures sheets don't work to well in Q3 because the game makes such heavy use of tiled placements (any which way).

[dONKEY]

@Kat,
Hey mate!
Don't get me wrong I wasn't suggesting the use of high res images for pointless detail (a la the hand grenade saga....I have a long memory:) ).
For the screen shot maps Sock was building I can fully see the point in wasting huge file sizes for visual results, but my question really was about where there any limitations in Q3 that would prevent the use of texture sheets or the number of large images, or if pulling textures from one source made any difference, either positive or negative.
Like I said my eye can not tell the difference between a texture density of .25 or .125.

[Kat]

*grin*

Ah yeah then obsidian hit the nail on the head, Q3 works more efficiently using smaller assets because it can swap those in and out of memory better (due to the aforementioned caching/batching/pre-fetching stuff), so sheets aren't as good for general level design in the game (models being the exception). With regards to density, if you can't tell the difference always go with the 'lower' (0.25) of the two... the compromise has always got to be getting more bang for your buck.