Setting texture size for detail

I'm trying to make sure I understand the relationships between textures size, prim surface size, and texture detail. It seems like 1024 x 1024 textures are designed for 10m x 10m surfaces, 1024 x 512 textures for 10m x 5m surfaces, and so on. You can adjust these using x and y repeats with the editor, but getting the texture in sharp focus is linked to its size, correct?

Oddly, it seems that most avatars are 8-10 ft. (2.4m - 3.04m) tall if you measure them against a stack of 1m cubes. Also it appears that a 1m cube in SL is not really a 1m cube, especially when dealing with textures.

When you place (1 repeat in each direction) a brick texture on a 10m x 10m or 5m x 10m wall surface and then walk up to the brick and look at it for size and perspective, it always is too large. It looks great on a fly bye from 40 - 50 m, but closer observation shows that the brick in the texture is too large. Thus, getting the correct appearance relative to the real world takes time with each texture.

I would appreciate insight from those of your with experience in this matter. Is this a SL "learning curve" issue or are there establish "rules/standards" for getting the surface textures size correct with excellent detail? I would like the brick to be real brick size if you are walking down a sidewalk and looking at the brick wall.

Thank you.

There's no direct linkage between texture size in pixels and surface size in SL. The general rule of thumb is to try and determine what size the textured object will usually be on the screens of people who see it based on an average screen resolution. Determine the resolution of the texture accordingly.

Thank you for the insight. I have a 2560x1600 resolution monitor. So if I understand you correctly, a texture applied to an object will look different size-wise on monitors of different resolutions. Is this correct? If so, I guess I make it look the way I like it and hope for the best? Thank you.

Prim sizes are correct. It's avatar sizes that are screwy.

The info on "avatar height" that is returned by scripted items like avatar rulers is, unfortunately, the height of their eyes, not the top of their head. Great for positioning Mouselook, lousy for calculating how tall you are. The result is most people are 6 to 9 inches too tall, at least.

There are also differences in how the SL cameras treat perspective versus how real eyes do. The end result is things built properly "to scale" based on real world measurements are roughly 25% to 50% too small.

In designing structures for SL, you need 4.5 to 5 Meter tall ceilings to allow decent camera angles and to prevent people from teleporting in and arriving on the floor above you, or on the roof. Hallways less than 1.5 meters wide seem very cramped, as do doors less than a full meter wide. With practice yo'll learn what looks right to you around typical avatars. Of course, then your first couple of customers will be a half-meter tall "Tiny" and a 40 foot tall macro Husky anthro... *smirk*

Pixel size of the texture or screen matters not. It's the repeats value of a particular prim face you're interested in. If the repeats on a face are 1.0 x 1.0, then the texture will be scaled to exactly fill that face (that is, where the face would be before any cutting and/or hollowing is applied to it).

I have this conversation a lot with students new to computer graphics. It's especially frustrating how the word "resolution" is overloaded and means like 3 different things.

Part of the confusion here is that people are confusing which size is being talked about when someone says "size." Like, a cube that is 1 meter in SL will have a different RL size (as in, hold a ruler up to the screen and measure it) depending on a whole bunch of factors.

There is no exact number because of the host of complicating factors. Chip's advice amounts to trial and error, and that is the correct approach. Just apply the image to the surface and see what it looks like. If it looks good, then good. If not, change the image size and see what it looks like then.

I mean, we could point out a general rule-of-thumb like "256x256 is a good image size for a texture with one repeat on a 2m tall object that will be seen from default camera positioning as an av walks past," but ultimately every situation is different. You could have an enormous backdrop that people will never get particularly close to, so you don't need a large texture even though the prims are huge; conversely, you could need a large texture on a tiny object because people will be zooming the camera in close to examine all the details.

Actually, there are several rules of thumb here...

But they're still trial and error a bit. Textures should rarely go above 256 X 256 pixels unless there is a clear, pressing need. The exception for that is clothes textures, which we know (we've been officially told) WILL be resized to 512 X 512 and "layered" to make a composite, so having them at 512 X 512 makes the sim work less hard.

Small is beautiful in SL - a few 512 X 512 textures with alpha channel roll in at 4MB each on your video card. Even if you've got a 512MB card you run out of memory pretty quickly. I'm currently standing on the top of my house. According to the stats bar I can see 1426 textures. If they were all 4MB in the card, I'd need a >4GB video card to cope with them all nicely. Just not a realistic option.

If there were all 128 X 128 pixels images, my 256MB card would just about cope full tilt and my SL would be a lot smoother.

The walls of my house have texture maps for the walls... they're displaying 1/4 of a 512 X 512 pixel texture. The prims are 10m X 10m, it's one repeat, and it works just fine, even at close range. As Chosen is fond of saying, possibly the thing SL does best is blow up small textures. You really can get away with much smaller than you think.

Well said, Eloise. The more I build in SL , the more I realize that smaller textures work surprisingly well. Even for an object that might occasionally fill most of the screen, a 256x256 is usually all you need.

yes I have been making textures smaller and smaller and they work very well. The only thing I make 512x512 is as has been pointed out clothing textures. I would never dream of going to 1024x1024 but I have received textures this size and chastized people for making them that size. (couple of creators I have seen do this)

I've uploaded some bigger textures. Texture sheets and long animations being the occasions I've done it. There *can* be reasons for it, which are legitimate, but they are, for most of us at least, the exception rather than the rule.

I understand the issue with large textures. But how about art? I mean, real life art loaded to SL, I usually scroll pretty close to it, and even 512x512 looks blurry that close. I myself would prefer less blurry, and I have only 64MB graphic card, still don't think such textures load too slow, at least during those slower hours in SL. I am a professional what comes handling graphics in real life, but still on the search of the best way to do it in SL, because what I know about print media doesn't apply to SL environment usually.

well SL isn't a medium designed to display art, the same way you won't use the same formats for displaying on the web and for getting it printed.

I usually try to stick to a resolution that is MAX twice the land resolution

If i remember the land is 256 pixels for 12 meters, which means 21,3 pixels per meter. if we round a bit we get 256 pixels for a 10 meter surface. This is , the resolution so what you build blend properly with the land.

Now using it twice for things that need some detailing is still acceptable so we have 512 pixels for 10 meters.

The only exception i can see is only for things with letters on them.

So far anyone giving me stuff that is over the 512x512 its not needed really. Also for signs I have never found a need to go past 512 yet. In fact i do quite well with 256x256 or 128x256 depending on shape. It show up very clearly and its on a 10 foot wide type thing. Either that or i am just "old" and my failing eyes dont see the inworld blur due to real world blur hehe, but I dont think they are "that" bad lol.

also to counteract the blur you can use a burst of the sharpen tool in photoshop it is usuefull to make this muddy text to show better on a small picture

I have some 1024x1024 textures made from photos, but they are covering a 40x40 prim. I'm going to see of I can reduce them without loss of looks.

I edit with the largest image I can get, then scale it to square or a rectangle with one side 1024 ... then start shrinking it 50% , repeating until the detail is crap. Then I go back to the 1024 original and make the scaling in one step (the detail is often better), or scale to one step before the detail went to crap, maybe do some pixel-by-pixel editing.

Unsharp mask (the GIMP) does a good job on bringing out detail.

Good thread guys. I have been making all of my textures 512x512, after reading this I'll try with smaller ones.

Chip Midnight has a very good point about texture size vs on screen size that I'd like to try to elaborate on. Let's say you have a 10x10 wall, and your looking at it from the middle of a room. Let's say then, that it's taking up about one 9th of your screen, like the middle square of a tic-tac-toe game. Let's say you have a 1280x1024 monitor, the cube will take up 427 pixels across the middle of your screen. Therefore, a 512 texture is slightly excessive and you could probably get away with a 256 one, but if your going to walk closer, then you'd probably want 512 if you want a fully detailed wall.

To argue the point for 256x256 textures, even if the wall takes up the whole screen, your still getting one texture pixel for every 5 screen pixels, so the wall will still look quite good.

Thanks.