I'm trying to learn how to create new bones for a custom object with its own mesh. So far I've figured I can create a new bone using the S3PE Rig Editor, now I'm stuck trying to figure out how to assign vertices to this new joint. I tried using Milkshape, but it seems to only show joints that already have assigned vertices. Since I created a new bone, there is no prexisting object with the bone I made. Similarly in TSRW, I can see my new bone in the bones list, but when in Edit mode for assigning bones, it doesn't appear and only shows bones that currently have assigned vertices.

Any pointers appreciated

With the rig editor only, you can't really assign bones to a mesh. So with that, you always want to be sure that in milkshape/blender the rig's name is present. Let's take a look at the standard one:

'0xCD68F001'. Also known as the 'transformbone'. If you open up every object, you'll always see the transform bone .

Now if we look at that same object in Milkshape/Blender then we see that the bone itself is also called '0xCD68F001'. Now, to get to more technical terms, transformBone, if we go to tools>FNV hash in S3PE and paste the word transformBone to convert it into a FNV32 hash you can clearly see that that's the same number as 0xCD68F001. So, how I usually add my bones is:

-Open the rig editor,
-Right click on the transformbone and click 'Add'. (That way you're sure they're, well, 'carried' around by the transformBone and not lost in infinity Or being seen as slots, which are also done by editing the Rig editor)
-In the Bone name, we want to put a unique name, the rig editor will convert it into a FNV32 hash automatically
-Copy paste the Hash names that Rig editor gave you onto a notepad (More easily with something like 'bone 1 = 0x00D57f0p' or something. So you know which bone was what again)
-In Milkshape/Blender/your prefered 3D program, you want to create a new 'Joint' or well 'Bone' too, select the vertices that need to have that bone adjusted to it and call it the hash name that you listed in S3PE

Thanks for the reply! TBH I prefer blender than milkshake. Two questions, so after creating the bones in rig editor. How do I create a new joint/ bone in blender? Do I first import the existing grannyrig file to blender somehow, make edits and export?

Hrm... I know that the exporter made for blender is a little bugged when it comes to exporting the bones properly sometimes. And we're mainly speaking of adding more bones than there already was. That's why you want to make sure you prepare the RIG file first before even importing it back into s3pe! Grannyfiles however is something you do not want to work with, mainly because ts3 converted those files into their own RIG files (They did this after the Pet patch was released). So if you're working with an older game version, I'd highly recommend updating the game so the current tools won't go berserk on you :P

For the bone stuff I think you want to have this one:
http://modthesims.info/download.php?t=456325

For export/import this one:
http://modthesims.info/download.php?t=433882

Personally I have never really applied bones for ts3 projects in blender, but if it works the same as how every 3D artist would apply RIGs/skeletons, then this tutorial might be useful: https://www.youtube.com/watch?v=mhQY2_gVoVg

(If it's not that, then just focus on the weight tool. I think what it was, is that on the side bits under the box icon (So not object mode obviously :P) there should be a hex-related name somewhere that is a bone. I think from there you can add a new one, give it the same name as the hex bone you've added in s3pe's bone tool and apply the weight where you want it to be.)

Hope this helps!

Thanks - I have my game updated to the latest version. I mentioned grannyrigs because that seems to be what I get from exporting the _RIG file from S3PE.
I've used the RSLT editor to make new routing slots before, but I've never thought about using it to create new bones for transforms lol

You're right about blender being bugged when exporting bones sometimes I think the first time I tried importing/exporting the MLOD file, when I tried to import the object to TSRW the object looked very unrecognizable. Another time I tried creating new bones like in that youtube video and exporting as a grannyrig and got some kind of error during the export. So I might have to stick with milkshape and figure out how to make the unassigned bones appear on the joints tab instead