Pixel size of wall texture?

If I want to make a customized texture that would fit on a 10 x 10 wall piece, 1 texture for the whole wall. What size texture do you recommend? Is 512 x 512 enough, 1024 x 1024? Bigger? Are there any major drawbacks to having a texture that large?

Other than the obvious problems with creating huge textures ( load time, level of detail degredation problems ) I've found that using the base of 2^2 for my larger paintings works great. In those instances you'd just start scaling out for the detail you want to be visible from that 2 meter sweet spot.

For a 10x10 wall I should think that anything less than 1024^2 would look highly aliased. For a regular painting I end up with something in the area of 1024x512 with matting and it looks superb.

-Skeal

I agree with Skeal and would like to add that the best resolution also depends on the level of detail in the image. If you want a 10x10 painting or diagram, you are going to need 1024x1024 (and yes, expect that to have an impact on sim performance, especially if you make a habit of it).

The streets in Midnight City are 10x10, and I use a 512x512 texture. The shades of concrete are a low saturation blue and you don't notice very much blurring.

I use a 128x128 for my shadow texture on some 10x10 prims because there is no detail at all, just a gradient from white to black (You can see an example of this on the floor of *PREEN*).

Finally in my photo studio I use a 128x1 pixel texture to create a blue-to-black fade on a 10x10 texture well.

So the trick is to try 1024x1024 and keep bringing the texture size a notch lower and lower until you get to a point where going any lower would be visually unacceptable.

Actually this is not a painting or a diagram, but a wall with transparent windows built into the texture. The idea is to reduce the number of prims required for windows by using textures instead.

The choice is between a wall that about about 20x10 with two windows that has:

9 prims, all with smaller textures

or one with

2 prims, with the same large 1024x1024 textures

You think the performance might noticeably suffer with option two?

One thing to keep in mind is that an alpha channel increases the bit size of a texture substantially. A 1024 32bit texture map could be close to a full mb in size depending on the amount of detail in it (it might even be more but we have no way of knowing how much conversion to jpeg2000 actually reduces it). I'd recommend using 512x512. Only go above that if you find the 512 version insufficient.

With this option would would be asking the engine to load up an instance of the image converter and mapping textures to distinct faces for each texture map. Even at 128^2 you only get 3 textures with comparable ram usage because of the overhead of loading the tmap in the first place.



This is a good option, and in fact for something like this it might make more sense to do a blend of the two options. Use a single texture for the wall and window hole itself, with a second primitive cube flattened down and having it's own texture to give the window the right kind of shape and 3 dimensional evocation in that situation.

Also in this case, you could easily change the tint or type of glass in the window by having the second object use a native color / opacity for the glass pane itself.

--edit--

By using the two shape method, you coudl easily use a 512 texture for the wall and wanes-coating(sp?) or whatever because you'd apply the detail of the window dressing in a smaller shape with a 128 texture mapped onto it. Even if you had two separate alpha channels you'd be better off than with 5 or 7 for the separate shapes entirely.

--/edit--

-Skeal

Here's something people tend to forget when thinking about texture size. Just because one object is "bigger" than another, doesn't mean it needs a bigger texture on it. Keep in mind how often the object will actually fill the screen. If your SL window is 1024x768, then you rarely see anything being 1024 pixels wide, and you never ever see anything being 1024 pixels tall.

Keep those textures small for two reasons. The first is, as I said, big textures are really unnecessary. SL is superb at redrawing small textures to full screen size, better than almost any other program I've ever seen in fact. The otheris that big textures eat bandwidth, disk space, and memory. Go to any mall in SL, look at the number of boneheads who fill their shops with 1024x1024's, and look at your FPS if you need proof. Too many big textures is one of the most common causes of lag in SL. The average mall has gigabytes or hundreds of gigabytes worth of textures in it while the average video card can only process in the megabytes. Remember, every time you use a 1024x1024 where you could easily get away with a 256x256, you're draining 16 times the amount of resources you should be. That's 16 times the load time, 16 times the memory, and 16 times the storage space.

There's almost NEVER a reason to need a 1024x1024. The only exceptions really are areas where you need a lot of text or other fine details that would disappear or blur at smaller pixel counts. Generally, 256x256 is plenty big enough for most applications. I've said this beore, a good rule of thumb is to have about 75% of your textures be 256x256 or smaller, about 20% of them be 512x512, and about 5% be 1024x1024.

The other thing you need to remember, if you are using 32 bit walls with window images to save prims, is that any objects outside with 32 bit textures are going to look like they are inside because of the alpha sorting problems.

This will include not only trees and grasses, but also things like privacy bars and property lines.

Just something to bear in mind. (And one of thes reason that more people don't build structures in this way.)

I think I'm going to give it a try with two prims per 10x10 wall section. The main wall texture 512 x 512 or 256x256 with the glass cut out out and then another smaller prim the size of the window which can have more detail to it. I think that's a great idea.

Thanks for the ideas everyone, especially Skeal.

Just my point of view:

I NEVER use above a 512 res texture. The load times become hellish at 1024, as does the video memory needs.

What people forget is it's not only them building. It's dozens of other nearby too. And if each use only one 1024 texture, well... I think you can see how that could snowball...

So 512 max for me.

I agree with foolish. Even my 10m tall trees use sport no larger than 512x512 and look detailed enough for my picky perfectionist self to sell.

It's not just malls btw, I've lag busted plenty of homes where the only problem was that ten minutes after landing my texture download window was still popping bars all the way across the screen with no end of the list in sight.