OBND Object Bounds on NPC

[whatrevolution]

Experimenting with Mator's TES5Edit merger script, I'm finding a lot of cases where NPC are missing OBND values. What makes it seem really odd to me is I'm finding evidence that Bethesda made changes to NPC records that caused OBND data to go into DLC ESMs, where it had been all zeroes in Skyrim.esm.

 

So, I'm finding records where (for example) a mod author makes an NPC change, and that pulls in Skyrim.esm values for its OBND. The same NPC will have been changed in a DLC, and the DLC ESM placed OBND data on the NPC record.

 

Example: Britte "Britte" [NPC_:000136B9] She's a Nord child in Whiterun. For the HearthFires DLC, OBND values are the only records that changed from Skyrim.esm in her actor form.

 

Across all NPC we have:

• Skyrim.esm provides OBND
• Skyrim.esm does not provide OBND
• DLC provides previously missing OBND
• Nothing ever provides OBND

Clearly, these NPC are working in-game regardless. The volume of affected records is quite large. However, I'm not finding a prior writing on any real effect of providing OBND data or not.

 

When it's given, I'm pulling the data forward into my merges. 

[DoubleYou]

Child needs OBND for adoption in Hearthfire perhaps. BTW how can

 

• Skyrim.esm provides OBND
• Skyrim.esm does not provide OBND

both be true?

[whatrevolution]

Child needs OBND for adoption in Hearthfire perhaps. BTW how can

 

both be true?

It's more accurate to say that there is always an OBND record on any NPC, and when I say "Skyrim.esm does not provide OBND" I mean that the record values are all zero for: X1, Y1, Z1, X2, Y2, Z2. Then, a later package (such as HearthFires.esm in my above example) modifies the record to provide other values.

 

Edit: Also, what I mean with the bulleted list is that all cases are found, in different combinations: ones that are possible! :D.

 

The two most common cases are:

 

• Skyrim.esm provides OBND
• Later DLC keeps the OBND data if it edits the NPC record

 

• Skyrim.esm doesn't provide OBND
• A DLC .esm does provide OBND
• A mod that has Skyrim.esm as master (but doesn't have DLC as master) pulls in the all-zero OBND data set from Skyrim.esm, overwriting the change that DLC made.

 

The most common values are: -22, -14, 0, 22, 14, 128. That seems to be a default across NPC of any size or age. However, there is variation. GulumEi "Gulum-Ei" [NPC_:00013284] is -24, -24, 0, 24, 24, 128. He's an Argonian.

 

I'm currently taking the set to be related to bounding volume of the actor model, and that's part of why I'm interested in the effect of it. That it's provided at all means it has a use (at very least it had an intended use). If that use is involved in simplifying some actor model related calculations, then it's possible that the game engine does extra work on every actor that doesn't provide that data set in its record.

 

It's also worth noting that 128 units on Z matches Bethesda's actor height assumption in level design. Amusingly, child bounding volumes are six feet tall by that measure.

 

Also worth noting that this can't be related to child adoption, unless adult male Nord Bandits are adoptable. :D

Edited June 15, 2014 by whatrevolution