Human game rig root bone location

Just a quick survey to see what’s common.
our game rigs have an unkskinned “root bone” at the origin, between the feet.

[QUOTE=Mambo4;25072]Just a quick survey to see what’s common.
our game rigs have an unkskinned “root bone” at the origin, between the feet.[/QUOTE]

Yes most do this gives a ground/origin snap point to reference. Some engines can create this internal so the skeleton doesn’t need it but I would say it is very common.

If your game uses animation driven movement/rotation (ADM/ADR) then one of the benefits of having a separate root bone is that you can separate the motion of the character from that of the collision capsule. So, for example, if you want your character to lean up against a wall then you can do that while leaving the root bone offset far enough that the capsule doesn’t intersect the wall. If your ADM is inferred from the pelvis then you lose the ability to separate those things.

Just to reiterate what the others have said…
Yes, it is common to have this root bone, whether handled programmatically by the engine or manually (and / or procedurally) animated and exported. IMO, a mix of manually and procedurally animated and exported root bone give better results and quality of animation (depending on the type of game, of course). If exported by animation, animators have more control, but also more to manage…which can be tricky aligning and matching poses for animation blending (feet sliding, popping, etc.). Also, an additional “sync” or “anchor” (terms may differ) bone maybe used or required to occupy/reserve cover nodes for AI when the character briefly leaves cover to fire, while the root bone correctly follows the characters’ location, in order to keep the collision box / capsule aligned and within the bounds of the character. Again, depending on the type of game and how smart the engine is.