slalphaglitch

[slalphaglitch]

What is this “alpha glitch” thing?

While SL has many different type of alpha issues, this fix is for when two rigged meshes with alpha textures make each other go invisible. For instance, your see-through dress may break your fishnet stockings, or your hair may make your top go invisible.

You used to be able to fix this by using bump and specular maps to assign priorities, but LL replaced it with a new method.

How do you fix the alpha glitching now?

There are two things that decide the priority: the attachment point, and the root prim transparency.

Let me explain. LL recently added priority to each attachment point, here is a breakdown of what priority each bone has. Please note that the lower the number, the higher the priority:

1 - Chest 2 - Skull 3 - Left Shoulder 4 - Right Shoulder 5 - Left Hand 6 - Right Hand 7 - Left Foot 8 - Right Foot 9 - Spine 10 - Pelvis 11 - Mouth 12 - Chin 13 - Left Ear 14 - Right Ear 15 - Left Eyeball 16 - Right Eyeball 17 - Nose 18 - R Upper Arm 19 - R Forearm 20 - L Upper Arm 21 - L Forearm 22 - Right Hip 23 - R Upper Leg 24 - R Lower Leg 25 - Left Hip 26 - L Upper Leg 27 - L Lower Leg 28 - Stomach 29 - Left Pec 30 - Right Pec 31 - [HUD] Center 2 32 - [HUD] Top Right 33 - [HUD] Top 34 - [HUD] Top Left 35 - [HUD] Center 36 - [HUD] Bottom Left 37 - [HUD] Bottom 38 - [HUD] Bottom Right 39 - Neck 40 - Avatar Center 41 - Left Ring Finger 42 - Right Ring Finger 43 - Tail Base 44 - Tail Tip 45 - Left Wing 46 - Right Wing 47 - Jaw 48 - Alt Left Ear 49 - Alt Right Ear 50 - Alt Left Eye 51 - Alt Right Eye 52 - Tongue 53 - Groin 54 - Left Hind Foot 55 - Right Hind Foot

Example: if you want to wear alpha hair with an alpha top, then you can attach the hair to your skull (priority 2) attachment point while attaching your top to the spine (priority 9). This way your hair won’t make your top go invisible. This has endless uses both for creators and residents, and can easily be switched up by anyone who want to change priority within their outfit. But there’s a catch, there’s also the matter of the blending options on the root prim:

While I have done limited testing on all the aspects around this, I can say for sure that a root prim that has transparency of more than 1% (including 100%), has a higher priority than a root prim with alpha masking or no alpha. This means that if your hair on the skull (priority 2) attachment point doesn’t have a transparent root prim, it will still glitch with your top on the spine (priority 9) attachment point. 

I believe this means all rigged mesh with alpha textures would benefit from having a root prim with transparency, as this gives the user freedom to configure their outfit freely.

Important: 

While the attachment point priority changes have been confirmed as an intentional change and should stick around going forward, the root prim transparency part is not confirmed. This means that it might not remain true in the future. 

Making your root prim 100% transparent instead of just partially transparent will help reduce lag.

This fix is only relevant for rigged/fitted/bento mesh, and will not work with anything unrigged/resize.

Please share this information as we all benefit from more people knowing about this