Skeleton

The skeleton is the base model containing all of the skeletal information for character and creature meshes in Oblivion.

Introduction

Each character and creature in Oblivion uses a base skeleton.nif file to hold the skeletal structure, collision and havok data, and bone LOD information for that creature. The skeleton files reside in the meshes\characters\_male folder for characters and in the meshes\creatures\<creature name> folder for creatures. The base skeleton is the first object brought into the game for rendering a creature, the mesh and animations are then applied to the skeleton and the bone structure contained in them.

Application to Characters

For characters there are two basic skeleton files: skeleton.nif and skeletonbeast.nif, which is identical to skeleton.nif except for the addition of tail bones. Any race with a tail mesh specified on the "Body Data" page will automatically use the skeletonbeast.nif, while races with no tail specified will use the skeleton.nif.

Modifying

WARNING: ALWAYS BACKUP YOUR FILES BEFORE EDITING.

The base skeleton can be imported into Blender, 3D Studio, or other 3d editing applications supported by NifTools. The bones can be modified and then exported, however at present the exported nif file does not contain all of the necessary data for use as a base skeleton (at least in Blender). The exported skeletal structure should be copied and pasted into the original skeleton.nif; care must be taken to make sure that the necessary flags, collision blocks, and extra data are moved to the new skeleton blocks and the old blocks deleted.

To add bones to a skeleton mesh for animating custom body parts, follow the same instructions above, making sure to parent the new bones properly to the correct base bones - ie. tail bones should be parented to the Bip01 Spine bone, wings to Bip01 Spine2 etc. Again make sure each block has the appropriate flags set and extra data blocks added. These can usually be copied from their parent bone.

Creature Skeletons

For creatures, they work in roughly the same way as a player's, but much more loosely defined in comparison to races, and so are the most customizable models. (Not to say that it would be impossible to have a non-standard race skeleton for an NPC, however.)

Like Race skeletons, the .nif files associated with the creature tend to show noticeable seams, though is necessary if this is to categorize the head and body as separate .nif files; if the head and body were not separated, NPCs would default to looking at the body rather than what we consider the head.