Hip Height (again)

Hello! I'm working on a set of animations for an avatar, and there are a few questions coming up. Probably more to follow!

I'm creating several 'sit' animations - ideally, I'll replace the standard 'sit on ground' and 'on object' poses using the AO, and also have some extra poses in HUD buttons.

I loaded up the SL BVH files to check hip height for their 'sit on ground's, and this is the first confusion - there appears to be a standard, where the hips are lower than Poser floor, and a 'constrained', where the figure sits *on* the floor. What's the difference? If I'm replacing 'sit on ground' with a new animation, which hip height should I use as reference?

Also, is this the right way to figure it out? I haven't had a single upload make the right place yet so I might as well check before I throw more money at it. Similarly, when I replace the 'sit on objects' anims, will I want to keep the hips in the same spot as in the SL BVH files? (It's tricky with the floor ones I'm doing because it's a kneel, not actually sitting on that ass, but if the theory is right the second set shouldn't be such a pain)

Thanks in advance - muddling through!

EDIT: Curses, any information on hip height for the AO would be useful! I'm used to setting it in the script of an object you sit on, so this is baffling me. My 'lie down' pose in the AO burried me in the floor (body in Poser resting on the 'floor') so I set hip height to 0 and surprisingly (not) I'm floating. My head also appears to be on backwards in spite of deleting the head and neck keyframes, but I think that's another post entierly Gah!

You set up the hip height positon at zero in Poser. If the distance between the reference ground and the hip height is 0.6m, you will move its hip down to -0.6m to have it sit on ground.
Meanwhile, if you create your avatar's height to 1.8m in world, the height of hip is supposed to be around 0.9m. That is equivalent to the zero height in Poser.
You should really move the hip down to -0.9m, that is, lower than the floor in Poser.

That must change depending on your avatar's heihgt.

Course, I'm an idiot. Thank you. I remember now raising an av through an anim using its hip height in game, so I'm even more of an idiot for not remembering or figuring out it works both ways. Cheers

So, this 'constrained' sit on ground... thinking about it, would it be that a different 'sit on ground' animation is played if the avatar has hips below a certain height? I don't even know if that's possible, just curious about why there would be two variations there.

Consider like the following.

[General]
When you sit on the ground, the system recognizes that your current state is "Sitting on Ground" and forces you to play the built-in animation, "sit_ground".
When you sit on an object, the system recognizes that your current state is "Sitting" and forces you to play the built-in animation, "sit".

[Using AO]
When you sit on the ground, AO recognizes that your current state is "Sitting on Ground" and forces you to stop the built-in animation, "sit_ground" and to play the animation that you set to replace it with.
When you sit on an object, AO recognizes that your current state is "Sitting" and forces you to stop the built-in animation, "sit" and to play the animation that you set to replace it with.

It is different state when you sit on between the ground and an object.
When you actually sit on the ground even though you sit on an object, your state is really "Sitting", not "Sitting on Ground". It is just coincidence that it happend. Your animation should be played the one set to replace it with "sit on objects".

So I told you it depended on your avatar height. If you avatar's height were 1.8m, your avatar's hip would go down to -0.9m when you sit on the ground. And it would go down -0.45m when you sit down on an object.
In the strict sense of the word, it might have something to do with the ballacne between its body and legs length.

hmm sorry, this seems not to be true. I guess the sitting on an object' process will go like this.

1. Standing on the prim.
2. Then playing "sit" animation.

So the amount of values between "sit on the ground" and "sit on an object" must be the same. The both must be -0.9m.

Anyway, I need to look through it more.

[Deed]
1. I made a stiffened standing pose named "Test Stand Pose".
2. I let my avatar sit on a prim cube.
3. I overrode the built-in sit pose by "Test Stand Pose".
4. I found my avatar stand on the prim, but its feet be a bit forward and sinking.
5. I let my avatar sit on the ground.
6. I overrode the built-in sit_ground psoe by "Test Stand Pose".
7. I found my avatar stand on the ground, but its feet be a bit sinking.

[Deduction]
When you make your avatar sit anywhere, your real avatar doesn't go down. It was just an animation trick.

[Deed]
1. I made the height of the prim double.
2. I let my avatar sit on the prim.
3. I found it sit on the top.
4. I overrode the built-in sit pose by "Test Stand Pose".
5. I found my avatar stand on the prim, but its feet be a bit forward and sinking.

[Deduction]
The system counted the prim height and the sit target is decided from the top of the prim.

[Deed]
1. I made a script to get the prim height and tried to find the sit target through a trial and error process.

[Result]
The formula seems to be the following.

The sit target = (The prim's height / 2) + 0.25 from the root prim axis.

0.25 is the height between the buttom of its foot and the hip while it is sitting. But it is the in-world measure. Poser's is another. It seems to be 0.367 when you use the SL male mannequin by my observation.
The most important thing is that the fitness depends on your avatar's hip size.

So this was theoretically right. The real both positions are the same. You just have to let your avatar go down to the ground when you'd like it to sit on the ground. And it should be its half when you'd like it to sit on an object. Sorry for confusing you.

Whee, thanks for all that! Possibly haven't had enough coffee for my brain to take it all in, but I think I see where you're coming from.

I had a play before reading your later replies - measured where I thought my hips were and then lowered the sit to there. Then I uploaded and played the anim above a flat, thin 'floor', and used prim sticks to measure the distance I'd got it wrong by, and tweaked it twice before it was about right. A bit of a faff, but it looks close enough, and works above ground or prims equally (so long as I don't try sitting in a hill...).

I can also scoot around on my ass with the movement controls which was a creepy but oddly fascinating side effect...

Thanks for all the thought you put into this. I will have a good study when I've woken up a bit!