Experiencing a Bug, and BoM Obscurities

Some folks with their own Experience scripts may have noticed a particularly nasty bug that's a real head-scratcher when first encountered. It seems that with some recent server update, all rezzed-in-world scripts compiled to any Experience lost record that they were compiled to that Experience. The scripts keep running using the Experience for which they were compiled, but they can't be recompiled (nor shift-drag copied, etc.) unless re-introduced to that Experience.

Turns out this doesn't really affect that many end-user scripts because most folks just use whatever Experiences are already compiled, and a lot of Experience scripts (such as the AVsitter auto-attach scripts I often praise) are usually embedded in object inventories, not rezzed-out on their own, so they weren't affected.

New objects don't seem to be affected now, but currently it's not clear whether there's any way for the Lab to fix the already damaged objects. If you're interested you can watch developments at https://jira.secondlife.com/browse/BUG-227526 for updates.
Much wider attention is on the new "Bakes on Mesh" (BoM) feature for attached mesh bodies and heads. This enables direct wearing of skin-tight textures and alpha masks, just as the old system avatars used, rather than the much more complex and limited "applier" scripts and "alpha cuts" HUDs that mesh attachments needed until now.

Much has been said about BoM already, but some things I think have been under-reported. First, in addition to the oft-cited improvement in rendering efficiency, the feature overcomes a constant source of user frustration and support problems: the unpredictable interaction of multiple layers of blended alpha textures. This comes up all the time when people try to wear makeup and tattoos, say, on overlapping layers of their attached mesh. All those problems go away when those overlapping transparent layers are simply baked on top of each other into a single displayed surface texture.

This also completely eliminates a problem inherent to how Advanced Lighting is implemented, limiting how many projected light sources affect a blended alpha surface. If you've ever noticed make-up, for example, looking weirdly coloured depending on where it is in a scene with complicated lighting, you've seen the problem -- which you WON'T see anymore with baked-on textures.

Finally, a note about BoM and Materials: if creators of BoM skin, make-up, tattoos, clothing, etc. want to include "Materials" effects, they should simply supply the normalmaps and/or specularmaps directly with their products, so folks can manually compose their combined normal- and specularmaps for the baked surface layer. These assets have zero value as "stolen" content, so the creator loses nothing by doing so, however much they may have been trained to "protect IP" at all cost. Mesh avatar makers understand this and provide a way to apply those manually composed material maps (at least this applies to Slink, which was "first out the gate" with BoM so I could test the existing built-in Materials applier on the skin layer, and a single-layer Omega applier for Materials will also work).

The reason this process still involves manual composition is that there's no simple rule for combining the "bumpiness" of normalmaps layered on top of one another. An under-shirt might be tight enough to reveal skin-layer bumpiness, but its own ribbed collar may not be revealed under a tight jacket, for example. It's still up to the user to decide which bumps should show through, and that means combining the normalmaps individually. (Most end-users may not want to do this themselves but creators of quality assembled outfits will surely follow this process for their customers.)
Reporter Qie Niangao

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