Second Life Forums Archive - Lag producing textures

Ravi Zuma

Я Вас не помню

Join date: 21 Jun 2004

Posts: 148

12-28-2004 04:47

To the experts out there: would you please post a list of image sizes, resolution, file size, quality, etc. for the following formats:

Targa
Jpeg
BPM

using the most lag reducing, yet still visually pleasing specs?

Thanks!

Malachi Petunia

Gentle Miscreant

Join date: 21 Sep 2003

Posts: 3,414

12-28-2004 05:33

Every texture uploaded, regardless of the source format, is stored on the SL server as a JPEG2000 file. Some parts of the SL rendering engine really prefer that the dimensions of the texture be powers of 2 (32, 64, 128, 256, 512, 1024). The largest image that SL will accept is 1024x1024 and will downscale anything larger so you are better off downscaling prior to upload. I think that non-powers of two will be rounded down to the nearest multiple before storing (that is 540 becomes 512).

The dimensions don't have to be square, SL is happy to take a 256x512 image, for example. I prefer to upload TGAs for two reasons, you don't have double compression loss (bitmap->jpg->jp2) and TGAs support alpha masks for transparency well. What if your image has a 3::2 aspect ratio? I usually scale to square (e.g. 512x512) and put it on a prim with a 3::2 width/height ratio.

The larger the image, the longer it takes the client to load, the more bandwidth it eats, etc. You'd probably be surprised at how much detail bicubic sampling preserves. I once started with a source image of 512x512 that was scaled down to 15x3 (yes 15x3) and was still quite recognizabble when stretched in the clothing stretcher.

The short answer is squeeze you image until the pixels scream - use 128x128 if that will work for your purpose, better still 64x64. Remember that most textures are not examined up close, so you can get away with quite a bit. Restrain yourself on use of unsharp masking as that seems to annoy the renderer and causes pixel dancing.

Don't open a texture store with auto-changing textures that switch before the last one has downloaded, as it makes for a bad purchasing environment.

Ravi Zuma

Я Вас не помню

Join date: 21 Jun 2004

Posts: 148

12-28-2004 05:54

Thank you. You have told me everything I needed to know. I'm not looking to open yet another texture store, just to reduce lag in my home.

jester Knox

Sculpter of Water

Join date: 22 Apr 2004

Posts: 204

12-28-2004 07:20

sorry ravi what this still isnt in reply to you but to add on to what malachi said usually if you are gonna scale something down run a blur filter on it first and then shrink it, counterintuitively the smaller image will look sharper because of it.

in reply to you lag in your home if you cant find any reason for your home to be causing lag then it might me the other land owners in your sim. but if you are looking for something texture based that you can control make the textures smaller and use less of them

jester

_____________________

people tell me my fountains are cool, come check them out at JesAma Fountains, Alviso (190,45) or if you arent in SL try Gigas (secondserver.net) or SLBoutique to shop for my products.

Eggy Lippmann

Wiktator

Join date: 1 May 2003

Posts: 7,939

12-29-2004 05:30

Think of what size your prims will have, and try to visualize how many pixels it will, on average, take up on your screen. Then resize the texture accordingly.
Heck, take a screenshot and measure the pixels yourself

_____________________

Help us document Second Life history at http://slhistory.org!

Maggie Miller

~Welsh Girl~

Join date: 17 May 2003

Posts: 290

12-29-2004 10:12

Jester,

Can you explain again why I should run a blur filter on a very small texture? I've made some small ones recently and have been having trouble with them being unclear in-world. Sounds like maybe you can explain why.

Maggie

jester Knox

Sculpter of Water

Join date: 22 Apr 2004

Posts: 204

12-30-2004 08:49

im not exactly sure how it works, but a large image (say 512X512) scaled down (allot like to 64x64) will look blurred and unclear. however if you run a blur filter over it first the resulting image comes out much more sharp looking. i think (really am just guessing here i know what happens not why) that it is because when you scale it down you end up with a smaller image that has been badly sharpened, the computer will attempt to keep all the fine detain and you can get artifacts or noise. when you blur it you soften all the edges so it reduces the over sharped look and will make more of the suggestion of detail that your eye will fill in as the actual detail.

blurring a small image will end up with a small blurry image. blurring a larger image and scaling down will end up with a clearer looking small image.

hope that helps

jester

_____________________

people tell me my fountains are cool, come check them out at JesAma Fountains, Alviso (190,45) or if you arent in SL try Gigas (secondserver.net) or SLBoutique to shop for my products.

Amanda Fauna

Creatively pondering

Join date: 21 Mar 2004

Posts: 72

12-30-2004 11:30

If i have a image that can be repeated alot, like a fabric pattern or wallpaper or such, then I think smaller sizes work best, as you aren't stretching the picture.
Most others I make 256x256.
If I need more detail shown then I will make them 516, but thats a last resort.

So many times I used to upload a image and not check its size. But not anymore.

_____________________

Baby & Co.

Closed!

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Lag producing textures - what's the best image size?

Lag producing textures - what's the best image size?
Ravi Zuma Я Вас не помню Join date: 21 Jun 2004 Posts: 148	12-28-2004 04:47 To the experts out there: would you please post a list of image sizes, resolution, file size, quality, etc. for the following formats: Targa Jpeg BPM using the most lag reducing, yet still visually pleasing specs? Thanks!
Malachi Petunia Gentle Miscreant Join date: 21 Sep 2003 Posts: 3,414	12-28-2004 05:33 Every texture uploaded, regardless of the source format, is stored on the SL server as a JPEG2000 file. Some parts of the SL rendering engine really prefer that the dimensions of the texture be powers of 2 (32, 64, 128, 256, 512, 1024). The largest image that SL will accept is 1024x1024 and will downscale anything larger so you are better off downscaling prior to upload. I think that non-powers of two will be rounded down to the nearest multiple before storing (that is 540 becomes 512). The dimensions don't have to be square, SL is happy to take a 256x512 image, for example. I prefer to upload TGAs for two reasons, you don't have double compression loss (bitmap->jpg->jp2) and TGAs support alpha masks for transparency well. What if your image has a 3::2 aspect ratio? I usually scale to square (e.g. 512x512) and put it on a prim with a 3::2 width/height ratio. The larger the image, the longer it takes the client to load, the more bandwidth it eats, etc. You'd probably be surprised at how much detail bicubic sampling preserves. I once started with a source image of 512x512 that was scaled down to 15x3 (yes 15x3) and was still quite recognizabble when stretched in the clothing stretcher. The short answer is squeeze you image until the pixels scream - use 128x128 if that will work for your purpose, better still 64x64. Remember that most textures are not examined up close, so you can get away with quite a bit. Restrain yourself on use of unsharp masking as that seems to annoy the renderer and causes pixel dancing. Don't open a texture store with auto-changing textures that switch before the last one has downloaded, as it makes for a bad purchasing environment.
Ravi Zuma Я Вас не помню Join date: 21 Jun 2004 Posts: 148	12-28-2004 05:54 Thank you. You have told me everything I needed to know. I'm not looking to open yet another texture store, just to reduce lag in my home.
jester Knox Sculpter of Water Join date: 22 Apr 2004 Posts: 204	12-28-2004 07:20 sorry ravi what this still isnt in reply to you but to add on to what malachi said usually if you are gonna scale something down run a blur filter on it first and then shrink it, counterintuitively the smaller image will look sharper because of it. in reply to you lag in your home if you cant find any reason for your home to be causing lag then it might me the other land owners in your sim. but if you are looking for something texture based that you can control make the textures smaller and use less of them jester _____________________ people tell me my fountains are cool, come check them out at JesAma Fountains, Alviso (190,45) or if you arent in SL try Gigas (secondserver.net) or SLBoutique to shop for my products.
Eggy Lippmann Wiktator Join date: 1 May 2003 Posts: 7,939	12-29-2004 05:30 Think of what size your prims will have, and try to visualize how many pixels it will, on average, take up on your screen. Then resize the texture accordingly. Heck, take a screenshot and measure the pixels yourself _____________________ Help us document Second Life history at http://slhistory.org!
Maggie Miller ~Welsh Girl~ Join date: 17 May 2003 Posts: 290	12-29-2004 10:12 Jester, Can you explain again why I should run a blur filter on a very small texture? I've made some small ones recently and have been having trouble with them being unclear in-world. Sounds like maybe you can explain why. Maggie
jester Knox Sculpter of Water Join date: 22 Apr 2004 Posts: 204	12-30-2004 08:49 im not exactly sure how it works, but a large image (say 512X512) scaled down (allot like to 64x64) will look blurred and unclear. however if you run a blur filter over it first the resulting image comes out much more sharp looking. i think (really am just guessing here i know what happens not why) that it is because when you scale it down you end up with a smaller image that has been badly sharpened, the computer will attempt to keep all the fine detain and you can get artifacts or noise. when you blur it you soften all the edges so it reduces the over sharped look and will make more of the suggestion of detail that your eye will fill in as the actual detail. blurring a small image will end up with a small blurry image. blurring a larger image and scaling down will end up with a clearer looking small image. hope that helps jester _____________________ people tell me my fountains are cool, come check them out at JesAma Fountains, Alviso (190,45) or if you arent in SL try Gigas (secondserver.net) or SLBoutique to shop for my products.
Amanda Fauna Creatively pondering Join date: 21 Mar 2004 Posts: 72	12-30-2004 11:30 If i have a image that can be repeated alot, like a fabric pattern or wallpaper or such, then I think smaller sizes work best, as you aren't stretching the picture. Most others I make 256x256. If I need more detail shown then I will make them 516, but thats a last resort. So many times I used to upload a image and not check its size. But not anymore. _____________________ Baby & Co. Closed!