It appears that the Lindens have changed the minimum size of an image

I have been involved in a project where I am importing image at a furious rate. An average of more than a dozen or more a day.

A few weeks ago I asked what the minimum size of a image could be on any given side, in other words the minimum divisor. I was under the mistaken impression that it was 32.

Chosen Few was kind enough to inform me that it was 8. And indeed I have imported a many images with that divisor and that was correct. Here is that post and replies...

What is the minimum divisor for images?
/109/ea/227426/1.html

3 days ago I imported 2 images that was 960 by 720 pixels and another was 1024 by 576, both were converted, on upload, to 1024 by 512 pixels.

Today I imported an image that was 304 pixels on both sides, it was converted to 256 pixels on a sides.

I find this deeply disturbing, at what point as a designer working for clients can I plan on a spec that is accountable? Does anyone have any further information on this?

This sounds right as rain as always to me. It's -always rounded down- to the nearest power of two (8, 16, 32, 64, 128, 256, 512, or 1024)...

the 960 becoming 1024 is new to me, but I've never uploaded something that close to 1024 without going over.

I'm not sure what you find disturbing about it. Everything resizes to the nearest power of two.

As I said in the other thread, you shouldn't be concerned with divisors. You should be thinking about powers of two. In order to prevent SL from resizing your images, make sure they always start out as powers of two in both dimensions. All powers of two between 8 and 1024 are allowable. No other numbers will work.

A complete list of usable texture sizes is in the sticky at the top of the forum.


EDIT: Yeah, Psyra, the upscaling to 1024 is relatively new. I don't know when that behavior started. It used to round everything down. Now it seems it will round up within a certain range. I don't know exactly what the range is. For what it's worth, I kind of wish they hadn't made that change, since smaller sizes always make for better performance.

I had asked before about the divisor, not the power of 2.

If I understand correctly, it is not that the number is divisible by 2 but the power of 2.

So one of the sides has to be one of these numbers?

(8, 16, 32, 64, 128, 256, 512, or 1024) ?

I may be finally getting this... set me straight.

Yes, you did ask about a divisor in your other thread. I tried to impress upon you then that you were asking about the wrong thing, that it's not about divisors at all, but about powers of two. Sorry if it wasn't clear enough.

Anyway, your list of numbers is correct. But you're still missing a piece of the puzzle. It's not just that one of the sides has to be a power of two; they BOTH have to be a power of two. This is a requirement of OpenGL, the graphics language in which SL is written.

EACH side must measure 8, 16, 32, 64, 128, 256, 512, or 1024. If either side is any number other than those listed, that side will get resized at the time of upload.

I had explained all this in point number 3 in my post in the other thread you linked. Sorry if it wasn't immediately clear then. Maybe I should have made it point number one instead.

I think you were clear enough, I just was not getting it. I have a long history in 3D and have not dealt with this kind of limit in texturing before. The mention of OpenGL burns it in a bit more as I know its spec.

Of coarse the liberal use of a baseball bat on me would have helped as well

Hahaha. I'll see if I can find one next time.

ROFL never quite heard it put that way before hehe

and yes those numbers can be confusing

(I love how folks help around it, it is nice to know if I get stuck I can come here for assistance)

I've found it to be quite annoying as well, and despite SOME experimentation I was not able to determine the threshold for upscaling. I really wish it only downscaled, for both performance reasons and for simplicity.