make T pose defacto standard

This goes out to Blender to start imposing T pose as standard rest pose. Mainly with Rigify.


  1. T Pose; 2) A Pose (Rigify default) 3: A Pose (Makehuman)
  • Notice how A Pose’s can differ.

A T pose is very specific and more precise than the current generated meta rig [A pose]; to try and impose it on every other app that touches blender via I/O such as Makehuman.

They [Makehuman] have also a very approximate pose when exported [I haven’t found a way to force a T pose on export].

Unity’s Mecanim use T pose as default pose.
Unreal to retarget animation a base pose is T pose.

The current A pose, AFAIK and have seen is slightly different from app to app, and this manually fixing the different takes unnecessary time IMO.

Good or Bad idea?

I would agree. T-pose should be the standard as it works best with MoCap retargeting and is the easiest to rig.

The benefit from using A-pose is that realistic deformations of the deltoids can be tricky to get right with T-pose rigs but for many rigs (especially on cartoony characters) this isn’t relevant or necessary enough to justify the added complexity of working in A-pose.
Disney, Pixar, Dreamworks, they all rig their characters in T-pose.

Plus T-pose is very clearly defined as having a right angle between the torso and the arms. With A-pose there are several ‘standards’, A45-pose (arms at 45°) and A65-pose (arms at 65°) but they’re not nearly as clearly established and oftentimes modelers just eyeball their A-pose.

If A-pose is required for a character then one can always go for it but it’s more of an additional and more specific requirement and I think it makes sense to have the default be a T-pose.

We can reach the developer of rigify and notify him, at least this T pose can be added additionally to the default A pose.

The advantage of the “A” pose is that all the joints are half bent. This is a better starting point to get nicer deformations.

Don’t really understand your post though - in Blender you are free to create rigs that default to a T-pose if you want. You can even make a new meta-rig for Rigify which defaults to a T-pose if you are so inclined.

Can someone briefly explain why we even care about this. Do animation tools, game engines and the like definitely expect a T pose, and what practical consequences does having some other pose have? What if your character has tail(s) or several arms and legs and T pose isn’t even possible. Do those tools just stop working? The whole notion seems quite mental to me in all honesty. Surely these tools (good and popular tools, I hear) are a bit more accomodating than that.

Anyhow, I find that shoulders in T pose are really hard to model and weight properly so I always angle them down. I would not appreciate a mandate to do it in some other suboptimal way. I also prefer to spread legs apart slightly to give some working room in the crotch area as well.

@Const @Chris Exactly, besides Nathan or the team behind Rigify to add Human (T Pose) Rigify, maybe rename current to Human (A Pose) , a huge benefit would be contacting Makehuman about being able to have T Pose for export as an option. I can see the benefits of using A Pose while setting up a human model, but the benefits would be huge to be able to have T Pose when imported to blender with use of a Rigify Human T Pose Meta Rig.

Also screenshot above shoves the inconsistency between Blender A Pose and Makehuman A pose.

@William I have done so, saved away a T pose version of Rigify that I can append into projects.

@AnvilSoup Yes they do, IF you want to be able to retarget animations T pose is the standard AFAIK and have seen from the two game engines I use Unity and Unreal. They don’t stop working, but the animations will be slightly off the more you deviate from T pose. Resulting in going back and fixing T pose.

I think, the bottom line is that A poses differ to much and T pose is the most exactly specified of them; hence why T pose is prefered.

I’d take the better deformation of an “a” pose any day of the week… and as you have done you can make a t pose default if you choose… ho hum, moving on!

I beg to differ,
I have made an animation library in blender with a T-pose and exporter those to unity and then at middle of the development I changed our characters rigs (but not animations) rest pose from T-pose to A-pose and unity’s retargeting tools did not have any problems retargeting T-pose animations to A-Pose rigs.

Bit of offtopic:
When you import animated character to unity and change animation type to humanoid and configure avatar
first press Mapping - Clear, Mapping - Automap
Then Pose - Reset, Pose - Sample Bind T-Pose, Pose - Enforce T-Pose.
And there you have it, your A-pose character in unity’s T-pose.

In my experience half-bent poses usually work better than “extreme” poses like the t-pose, at least for realistic meshes.

I understand your reasoning for wanting the T-Pose and all aermartin… but the A-Pose is used for good reason, namely better deformations and easier weight-painting. I both sculpt in the A-Pose and rig with it. I’ve tried the T-Pose and the shoulder + elbow deformations never work out as well. Have a look at a few animations not specifically testing the extremes of motion; the T-Pose shoulders are quite far off the bends one gets in a general animation. In general, I like to have the mesh sculpted & weighted in a pose that’s going to minimise the number of extreme deformations seen - especially if there is easily seen muscular (or other) detail at that area like with the shoulders & chest.

Yes, my A-Pose is going to be slightly different than perhaps Cessen’s or Michael W’s. Hell, my A-Pose generally is slightly off for each figure that I do (they’re humanoid, but not human). However, it takes a few seconds of editing the input Rigify skeleton to fix that. Rigify then “just works”. I don’t really see a problem here, more a preference.

That all said, I see no hassles with adding a T-Pose option if that helps people. It is indeed a common pose for those working with mocap and Blender’s mocap retargeting is… well, I’ll agree it needs as much help as it can get.

There was a hot debate for a while at dreamworks about t pose vs a pose… A-pose gives nicer deformations, but it’s easier to rig in t pose… Plus you can guarantee the 90 deg arms will be consistent between characters, while its easy to accidentally model an a-pose that’s off by a few degrees…

eventually we we settled on t-pose for consistency - plus the deformation tools were so good that they handled the extreme deformations really well!

-Jason

Good to see such compromises still get argued even at Dreamworks. Makes us plebs feel a little better about not having settled it ourselves :stuck_out_tongue:

That said, if Blender had the deformation tools available to you guys - I couldn’t care less which was default!!! :smiley:

Um, do we really have a choice nowadays? Haven’t made a rig for a long time. But as far as i remember you will be in big trouble in Blender with a T Pose, since the IK has its own will then. The Blender joints needs a minimum bending to decide in which direction to bend for IK. I once got told that i will get used to. But never did …

T-pose does include a slight bend in the knees and the elbows for IK. But only a minimal amount. The T refers to a 90° angle between torso and shoulders, less about the angle between upper and lower arm.
This requirement of a slight angle is true for all IK systems, not just Blender’s.

Well, that’s not really true. I’ve worked with quite a few other solutions in the past where i was able work with straight angles too. Even with angles that were far away from 90 degrees, at the other side of the flip point. But yeah, it’s been a few years. And evolution goes not always just forward it seems ^^

It’s already the 90 degrees of the shoulder in T - Pose that can make big trouble with IK in Blender. That’s why the recommended way is the A pose here. Thus my comment.

What are we talking about here? Are we talking about planar IK between three joints as is commonly used between upper arm, lower arm and wrist as well as upper leg, lower leg and ankle? Or are we talking about FBIK (Full Body IK) which many riggers including myself stay clear off because it’s often very unreliable and unstable?

Specifically for the former it’s much easier to align the joints correctly for IK in a T-pose than in an A-pose. Since all three joints have to be on one plane (with their local axes aligned accordingly) you merely have to make sure the upper arm joint, lower arm joint and wrist joint are on the exact same world Y position (or world Z position in Blender). Much more cumbersome to align that correctly on an A pose.

Also, could you point me to which IK solutions you used that don’t require a slight initial bent angle to work stable? That’s news to me.

You can make your joints straight in edit mode then in pose mode bend them a bit before applying the ik constraint, I can’t remember in which chapter of Humane rigging Nathan explain but anyways…

Interesting discussion if I may ask a few questions, in the t-pose do you guys model the arm pronated(palm facing the ground) so all the forearm muscles are twisted or supinated(with the palms facing foward) so that the are in a relaxed state?

For eyes is do you go model them closed or open? I was doing a face rig last year and it went tits up for me because I modeled the eyes open but then the were not enough loops. I then watched a modeling demo reel from someone who works at Pixar and all his models had the eyes closed so it got me wondering.

Wrist in pronation (palm facing down) is the industry standard.

Brian Tindall from Pixar, author of The Art of Moving Points (highly recommended!) has these reference images for pose and topology on his website:
Modeling for Articulation



http://www.hippydrome.com/Images/ArmsShldr/ArmsUDFront.gifhttp://www.hippydrome.com/Images/ArmsShldr/ShldrFBSolid.gifhttp://www.hippydrome.com/Images/ArmsShldr/ShldrUDSolid.gif

You can download his free reference model here.

Also, could you point me to which IK solutions you used that don’t require a slight initial bent angle to work stable? That’s news to me.

I’ve worked with all the trueSpace bone solutions from version 4 up to 7.6. That were three over the years when i remember right. Two official, one as a plugin. I had also my fingers at the usual cheaper solutions over the years, while searching for the best pipeline. Fragmotion, Messiah, Anim8tor, Milkshape, and a few other more unknown and long forgotten solutions. In all i was able to work with a T-Pose, without the need to remodel my mesh to A pose or to do angle measurements if i am still below the flip point. And the IK (if available, tS 4 had obviously no IK) worked just fine. As told, with even beding the joint ways behind the flip point while rigging.

Blender was the first solution where i miserably failed with a T-Pose. I was trapped more than once by that i couldn’t convince a joint to bend into the other direction anymore by IK. I had even raised a bug report back in those days. Ton then told me that i have to bend the joins already into the right direction while rigging, that i have to get used to because it’s the way it is. And so i use the A pose since then.

As told, my comment came not out of nowhere.

But when you say that nowadays every IK solution needs a slight bending, then i take your word. Since i cannot argue with you here anyways. I haven’t toyed around with the nowadays solutions this much. I mainly use Blender nowadays. And am used to the A pose since T pose gives me too much headaches while rigging here.

You can make your joints straight in edit mode then in pose mode bend them a bit before applying the ik constraint, I can’t remember in which chapter of Humane rigging Nathan explain but anyways…

Great hint. Thanks in the name of everybody who has trouble with T Poses in Blender :slight_smile: