Texture size

[SimplySerenity]

What's an appropriate resolution for universal textures? I've noticed that when I had my textures at 128 x 128 the room looked brighter than when at 512 x 512. So I was wondering what's the best resolution for them?

[ceriux]

have you tried looking at the default textures?

[SimplySerenity]

You have a point. But, that was before. Computers can handle higher res textures now so I don't think that's really valid.

[Dr. Shadowborg]

[SimplySerenity]

I was asking about the external textures actually. ^.^ I'm already using them :3

[mh]

Optimal texture size depends on how many textures you have in your map and how much video RAM you have. If you exhaust video RAM your driver will swap them out to system memory and then swap them back in to video RAM again when they're needed next. This sounds fine in theory, but in practice it gives a worst case of needing to swap an entire texture set if you do a 180 degree snap-turn.

Hardware limits on texture size still exist, but on anything reasonably modern you're unlikely to ever hit them. They're also nowhere near as important as the above. Just be aware of them and hope that your engine can fallback gracefully (e.g by downsizing the texture).

For a typical-ish Quake map with maybe 50 unique textures, using 256x256 textures will give you about 18mb of video RAM usage (that's assuming no normal/gloss/luma/etc). You're also going to need headroom for the framebuffer, depth/stencil buffer, lightmap textures, MDL and SPR textures, and other non-map textures (console/menu/sbar), as well as for anything else the driver may allocate (e.g. it may be emulating immediate mode via a dynamic VBO, or your engine of choice may use VBOs already). So I'd say that this size seems good for a 64mb to 128mb video card.

[mankrip]

As for the problem described in the first post, can an external texture's size affect its lighting?

[SimplySerenity]

Thanks for the answer mh. Mankrip it seemed to affect the way my room was lit, I'll take a few screen shots to show it.

[SimplySerenity]

Yeah, It's not doing it anymore. But, I do know what caused it. When the lighting effect is set to high it has this problem. I've got it set to normal now, and all the textures look the same.

[SimplySerenity]

So I just set it to full and changed out the textures while taking screen shots, and you can see only slight differences sadly. Before when I had done it, it was pretty noticeable.

[Spirit]

I remember external textures having different lighting discussed at func a while ago. Of course it might just be that the files had more brightness. No idea.

[mh]

As far as the light calculation is concerned it's just a simple multiplication of lightmap level by texture colour, so if lighting is affected then it must be due to the texture colour being different.

There are a few possible causes of this, but they depend on the engine you're using.

In GLQuake for example, the palette colours are adjusted according to the value of a -gamma command-line option, if used. This will translate into brighter looking lighting for native 8-bit textures, but darker for external (as they have no palette and therefore don't pick up the adjustment) if you're using an engine that retains this.

That's just one way in which this can happen.

I don't see how going from a 256x256 external texture to a 128x128 external texture could affect brightness, unless the texture image picked up some other adjustments in addition to the resize.

[SimplySerenity]

I was using darkplaces.