v7 beta documentation in progress. v7 beta documentation may be incomplete or inaccurate.
v7 functions and features may be significantly different from previous ACS versions.
These instructions are not valid for current v6+ ACS!
ACS starting with v7 uses a proprietary link tracking system stored in non-root-prim description fields that allows you to link and unlink prims in the linkset while building, without breaking link number assignments with prim animation, doors and accessories assignments. The code uses its own ACS UUID system and updates it on duplicates, so that duplicate shift-copied prims with the same SL UUID do not break any indexing system used to track link numbers in the scripts.
The link tracking system also allows many properies to be stored in the prim description such as various lights, graphics and fixtures group assignments. These assignments stay with the prims when link numbers change, or when unlinked, and transfer over to other vehicles when re-linked.
Mesh prims can have up to eight faces, and up to 256 individual links are allowed in Second Life objects, meaning up to 2048 individual prim faces have to be accounted for. Earlier version of ACS were designed for the original 32 prim vehicle limit, and single-faced sculpted prims and thus mostly had to account for and store memory for only 32 prim faces.
Storing data for up to 2048 prim faces is not really plausible for the limitations of script memory, so the link tracking system eliminates the storage problem by storing data with a compact code in link descriptions. This code is automatically written to any prim added to an ACS vehicle if it does not already have a code assigned.
This v7 link tracking system is designed to be compatible with future ACS updates and revisions, major or minor, unless Second Life introduces prims with more than eight faces.
If you have a 3rd party script that also needs to use a prim description field on an individual prim, you can opt out a prim from using the ACS tracking system on it by placing the skip keyword in the prim name field. You will not be able to assign light faces, ACS graphics or fixtures to the prim, although you can still use ParticleSystem keywords with it in the name field, and run individual component scripts (such as wheels, Belt Drive, Chain Drive, Vibrator) from that link.
The Link Tracking System does not use the vehicle root prim, and neither do most of the graphics/lights/etc systems access the root, as the root is assumed to be transparent and hidden from view. Your vehicle as an object will show the name and description and creator of the root prim, so when you are done building, if any ACS link tracking system code is written to the root prim, you can manually erase it/replace it in the object description so that your vehicle does not show weird ugly code when being examined. Code can get written to the root description if when linking/unlinking prims, you accidentally make another prim to be the root.
LL has yet to introduce the code allowing the changing of materials textures at the scripting level. There is no guess when this will happen, but data fields were built into the Link Tracking System to allow for materials groups assignment for prim faces whenever LL finally introduces the scripting commands.
[v7 Main]