Several rest poses?

Hi folks,

I’m kind of confused with “rest poses”. The doc says we can save several rest poses but… whatever the way I’m doing that, I always end with one and only rest that propagate to poses (what I mean is if rest is 0° and I create one with 10° rotation, the 30° pose will become 40°). I’ve tried to fake user but rest changes propagate in all poses libraries. Is there anyway to have several rest poses that are not “pose” but “rest”?
My character needs two modes with a specific default rest for each. Is there anyway to do that? Or I have to create two models, which will share some materials rendering properties? That means to switch model depending of the mode, that’s not really convenient for my project.

Can you link to the documentation that says you can have several rest poses?

There are two things you can do. One is to simply create poses in the pose library. These are easily recalled. You can consider using an NLA strip to layer other animation on top of base poses.

The other is to make another armature (or a layer in your armature) full of non-deforming bones, in a different pose than your main bones, and then use copy transforms constraints to acquire these bones’ orientations. You’ll want to create a driver for the influence of all copy transforms constraints so that you can easily switch. This is a lot of tedious work, but can be necessary for some kinds of animation data.

Hello,

Thanks for the reply.

Well, the part about pose libraries is kind of confusing : https://docs.blender.org/manual/en/latest/animation/armatures/posing/editing/pose_library.html

The pose library is the first thing I used. It remains usefull to keep some pose references but “rest” propagate between libraries. As you say, I will need another armature. I’ve checked, even in UE4, we need different armatures too and to build links with blueprints.

Sad, but never mind, I will deal with it.

I guess you refer to that missleading sentence:

The pose library is a way to store pose positions so the same position can be used again later in the animation or to store different rest poses.

TL;DR: The doc tries to say that you can use the pose library to store poses that you can use as default pose. But you never touch the rest pose. Click me for more details.

You can’t create several rest poses. The rest pose in Blender is what is called the “binding pose” in the industry. Its function is to tell your software what are the default bones transforms and how each vertice is located from its influencer bone. It’s a technical notion that is supposed to be dealt with once and for all during the rigging process and never changed afterwards. As changing the rest pose affects every other pose & animation of the rig.

The “binding pose” is often not usable for animation, as it’s usually a T pose or A pose whose only use is to have straightened bones (which is unnatural) as reference while having the vertices not too far from what they will do once animated (which will make the skinning process easier and the deformations more accurate). In fine the “binding pose” is only usefull for the rigging. Not animating.

But, when a character is animated, the animators will usually create at least one “default pose” (usually just the character standing up in a neutral way, or in accordance to his characterization). Which they will start from almost everytime they do an animation. In fact, they will spend a lot of time building an entire library of different poses so they can work quicker aftewards: default stands, crouch, facial shapes, hand shapes, etc.

Unfortunately, the notions of “binding pose” and “default pose” does not exist in Blender. There’s only the “rest pose”, that is technically a “rest pose” considering its technical traits, but sometimes people try to use the rest pose as a “default pose”, leading to some confusion as to what you can/should do with that.

So when you use the pose library, you never touch the rest pose. You just store regular poses with the extra bonus of assigning them a name and not having to use your already cluttured timeline to store them.

Hello,

Yes, I saw that. I suppose I will have to find some tricks with two models and skeletons and switch when needed or I will try to find my way with shape keys and data transfer. Until now, data transfers fail, I need to parent directly with autoweight to make it work. I will try again with new clean meshes.

(To give an idea about what I try to achieve is more or less like a character who can have clothes but also a exoskeleton and the rest pose is not exactly the same.)