Update on SSA

Surely by now you know SSA is Server Side Appearance, which is about baking your avatar appearance. The Lindens have posted a second notice that SSA will be here next week. See: It’s Time to Update Your Viewer!

And they reuse their previous video:

Please make sure all your friends know about the coming update and the need for them to be using a recent version of whatever viewer they use. 

Clean Up

I’m in the process of upgrading my computer again. In that effort I am also cleaning out all the old viewers. Viewers like Kirsten’s S22, Imprudence, Exodus, NiranV’s, Ascent, Zen, and others that will not be upgraded are going to be essentially useless to me. So, it is time to uninstall them and clean out caches and chat logs.

All the old viewers, Linden beta and project viewers also all had to go.

I back up all the chat logs before any uninstall. The newer versions of the viewer’s uninstall programs give you a choice about whether you wipe out the chat logs. But, I had some old version of various project viewers. So, a backup is important as I never know which ones will do what.

Use the link, Luke...

Use the link, Luke…

Also, if you look in the Program Files folder and find the folder for the version you want to uninstall, you will find an uninstall program in each folder. Use the ‘link/shortcut’ to start the program. It sets the options so the uninstall program gets the right files.

The Avatar Bake

If you have never understood what is changing or how the avatar bake is ‘baked,’ here is the short version:

Rendering the avatar is a special rendering case. It is a more complex process than rendering the other objects in Second Life. The idea with avatars is to save CPU cycles on users’ computers and the SL servers. The idea requires your viewer to download all the textures that make up your avatar and its clothes; a shape, skin, top, pants, hair, and shoes textures. The viewer ‘bakes’ those into a single composite texture. You see your avatar render nice and sharp when that bake completes. Then your viewer uploads that composite texture for all to see. That saves others downloading all the individual textures and baking them. Your avatar goes blurry as it downloads and decompresses the composite texture you just uploaded and it becomes sharp when that process finishes. You are the only one that sees the double blurry for your avatar.

With SSA that process changes. Rendering the avatar is still a special case. Your viewer will still download all the textures needed to make up your appearance and use them to bake a composite texture.

As you change clothes, skin, eyes, and etc. your viewer updates the COF, Current Outfit Folder. It requests the textures needed. The skin texture is applied and then over it the Alpha, Tattoo, and clothing layers are added. The viewer combines, bakes, those into a single texture. While this is happening you may see the old texture for a bit and then see your avatar go blurry. As the bake finishes, you see a sharp, crisp render of your avatar.

To this point very little has changed in the process. It is also likely that this part of the process has always worked for you, unless you have a really weak connection to SL, which is different than a good general Internet connection.

Once you stop changing appearance, the viewer sends a message to the SL servers (it is a time out sort of thing) and they start the SSA process. The COF updates in your viewer and at the SL servers as you change appearance. If you can wear something, COF has updated. This means both your computer and the SL servers know what you are wearing. The SL side SSA uses the server side information to collect all the textures needed to bake your appearance texture, the composite of all you are wearing.

The SSA servers then cache this texture. Anyone that sees you gets a copy of this texture.


One of the problems with avatars failing to bake is the bake process used viewer side. Not all viewers use the Kakadu software to create JPG2000 images for upload to SL. That means the image baked by the viewer and previously sent to the SL servers may not be all that compatible.

Now that the server bakes the composite appearance image, everyone’s appearance texture will be made by the same software.


If your connection to SL is shaky, having a good Internet connection doesn’t mean a good SL connection, then problems with the texture upload and download could keep your avatar from rendering well. If the upload went poorly everyone would see your avatar messed up.

Now if you can change clothes, no matter whether you can get your new appearance texture or not the rest of us will likely see you well baked… in SoCal that has a whole other meaning… here I mean your avatar will look sharp and crisp to us.

Chances are that even if you do have a poor connection to SL things will work better for you. In general there are fewer problems with downloads than with uploads. Since you no longer have to upload your appearance texture, there is less chance for a problem.

If you are having appearance problems, you are definitely going to know it now. Others may not notice when looking at you, but you will. If your connection to SL is so bad you cannot bake your appearance, you may not be able to download the SL baked appearance. This should give you incentive to find the connection problem. But, it is going to have less effect on the rest of us. Also you won’t accidentally appear nude.

Why the New Viewer?

The viewer has to change how it handles getting your composite appearance texture. If the viewer does not have the new SSA compatible code, it will never send the ‘Please bake me now’ message to the SSA servers. Also, the SL servers will not accept your baked texture. So, there will not be one for you or anyone else to download. You will be permanently gray. Everyone will see you as permanently gray.

I expect you will see your appearance bake once and then go gray. The ONLY way to fix that is to get a viewer with the SSA code.



The Lindens will likely start enabling SSA on the release channels first. Expect to see some of that on Monday July 8. The software is already on the servers. It just has to be enabled. If load on the SSA servers is as expected and no problems are found then I think it likely this change will sweep across the grid rapidly.

That means a flood of people will suddenly be updating their viewers at the same time. Download servers and support people are likely going to be overwhelmed. Plan ahead and avoid the crunch.

5 thoughts on “Update on SSA

  1. No, Nalates, with SSB, the viewer doesn’t bake the textures anymore itself (it doesn’t download and composite the textures to finally upload them to the sim server for other viewers to get the composited (baked) texture).
    Instead, the viewer populates the COF with links to whatever body parts and clothing items your avatar is wearing, then it sends a “go for it and bake” signal to the server that does the job the viewer was previously doing and replies with a texture UUID that references the corresponding baked texture that all viewers (including yours) can download to render your avatar.
    In fact, what gets avoided with SSB is the baked texture upload failures and the many race conditions between viewer and server baked textures updates, but on the other hand, with SSB, the viewer may as well fail to create the inventory links in the COF (asset server failures to create inventory items are far from rare) and the bake will fail as well in that case. Months ago (almost 1 year ago now) I proposed instead to LL to send the UUIDs of the worn items with the “go for it and bake” message instead of using the COF, but LL ignored my suggestion…

    • Henri, you are mistaken. Nyx Linden has explained what the new code does. While we are changing appearance, the viewer is baking the changes we see, until we stop changing appearance for some time.

      Ask Nyx.

      • The viewer is indeed using local textures to render your avatar *as long as the server-baked texture is not received*, but the resulting baked texture is *not* uploaded to the servers: that’s the whole point of SSB: to avoid the uploads that were more than often failing or which repetitions caused race conditions.

        • You are correct the viewer baked texture is NOT uploaded to SL. But, the viewer bakes your appearance while you are in Appearance editing mode.

          • Which doesn’t matter the least as far as normal baking is concerned. Appearance *editing* happens quite rarely (in amount of both (local) bakes and total render time in a session). Note that when you change clothes, appearance *editing* is *not* involved and, in SSB sims, your viewer just updates the COF, asks the server to bake the texture and waits for the baked texture to be reported as ready before downloading it to render your avatar with its new outfit.
            What counts with SSB vs legacy algorithm is the fact that the avatar composite texture baking happens *entirely* server-side in the former case and *entirely* viewer-side in the latter case (with the exception of appearance editing mode, i.e. when you *change* the textures or visual parameters of a wearable or body part): your description of the SSB process made it believe that the viewer was still responsible for the texture baking, which it is not.

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