Robot skeleton - Assaultron attachments, how they connect?

[Roggvir]

I am putting together a complete Assaultron skeleton, that can be used in Max to properly position and connect all imported Assaultron parts (need this as a base for porting the Assaultron to a human skeleton).

 

I have a nearly complete skeleton, got everything figured out, except the claws.

How is the claw physically connected to the arm?

Which exact point in the claw mesh gets to which exact position relative to the arm?

 

The attachment point is P-HandLeft/C-HandLeft.

P-HandLeft is defined in the arm NIF as a child of LForearm1, with a relative XYZ position.

C-HandLeft is a bone in the claw NIF, but the actual claw mesh is skinned onto a series of Pt_* bones, with its root Pt_HandRootBone being on same level in hierarchy as the C-HandLeft.

 

If i connect the claw to the arm using the arm-relative position of the P-HandLeft as a point where i place the C-HandLeft from the claw NIF, the claw is obviously in wrong position (pushed into the arm).

If i try the same except placing the Pt_HandRootBone to the position of P-HandLeft point, i get similar result - the claw is still in wrong position.

 

Now obviously, when i import the NIFs into Max, i can see where should the claw be approx. positioned and move it there manually.

And i did just that so i can finish my project, but i would like to do it the right way, not with my sloppy eyeballing.

So, how does it work? how does the game know how to position the claw relative to the arm, using just the data in both NIFs (the existing bone positions in those nifs and the CPA definition)?

 

 

EDIT: i attached the WIP skeleton

skeleton assaultron.nif

Look at it in NifSkope, especially at the C-HandLeft and Pt_HandRootBone position (if i change Pt_HandRootBone's negative X value of -3.569763 to positive, then the resulting claw placement seems almost correct - so, maybe the Pt root bone position needs to be inverted? but what tells the game to do that? no such thing was neccessary for any of the other parts).

 

EDIT 2: here is how the claw gets positioned after importing into Max, using the WIP skeleton

(note how the claw's forearm is burried into the arm elbow)

 

[Roggvir]

OMG, i am so stupid, its so obvious!

 

1.) Get the position and rotation difference between C-HandLeft vs. Pt_HandRootBone in the claw NIF.

2.) Apply same difference to C-HandLeft in arm NIF to get correct position for Pt_HandRootBone

 

Let this topic here be the monument to my stupidity