[x3d-public] FW: [x3d] Spec Comment by dougsanden on 19774-2: HAnim Motion Capture -V1.0

Fri Jun 26 15:46:11 PDT 2020

Q. HAnim Examples > What does the to-do list look like?
I ask because I got a sense that no new / modified HANim nodes would be
considered beyond official HAnim2 until examples cleaned up.
Is there anything blocking that? I ask in case someone has something that
can help.
One thing that popped to mind: is there a problem getting authors
permission? If so and an example was demonstrating a particular thing,
perhaps that scene can be dropped and a new one authored or volunteered by
others reading this who may be sitting on some assets or capabilities that
can volunteer equivalent scenery.
-Doug
more..
On the horizon: glTF skinning which may have the effect of bypassing HAnim,
perhaps obsoleting HAnim in practice.
https://www.khronos.org/files/gltf20-reference-guide.pdf
- p.5,6,7
Getting past blockages in the HAnim project and on to node improvements
might help later when harmonizing with glTF skinning.

On Fri, Jun 26, 2020 at 3:52 PM Joseph D Williams <joedwil at earthlink.net>
wrote:

>
>
>    - My conceptual model is a bit different.
>
>
>
> That is OK by me as long as it works. Whatever, Joint hierarchies will
> operate just like practical hierarchies of standard x3d Transform nodes,
> using center of rotation concept.
>
>
>
> For the Humanoid, if there are more joints in the capture than the
> playback, then you “ignore” some sets of values. If there are more joints
> in the playback than the capture, then, if the hierarchy is still ok, you
> don’t send events to the extra joints, or just send the default.
>
> The x3d tool should be able to help an author by first giving a list of
> what joints, segments, sites are available in the playback skeleton defined
> In the Humanoid skeleton. All the author needs to do to use existing x3d
> timer/interpolator/route animations is connect up the animation events to
> the skeleton Joint DEFs. Multiple, selectable animation routines can reside
> inside or outside the Humanoid, and prototype behaviors are very usable and
> very sharable between similar characters. In general, these animations are
> designed for realtime rather than frametime, but of course can be used to
> produce a frame at any time. However, these animations by themselves may
> not directly define the skeleton they apply to, or the initial pose.
>
>
>
> For x3d HAnim Humanoid Motion style, I think we are trying to access a
> perhaps more public range of animations, by the easiest way possible. From
> what I have seen these mostly use capture intervals related to video or
> film and are typically oversampled for typical realtime needs, and also,
> since mainly using xyz data, are subject to unpredictable animations,
> particularly fast wide motions. However, we want to make it convenient for
> an author, so we want to use the data in the bvh file to help connect the
> skeletons with the data.
>
> Turns out this may be easy because the bvh file contains configuration
> data for the capture skeleton as well as the animation data. Now all we
> must do is connect the skeletons and then the data and events are all
> handled under the covers. In this case, it is possible that a tool could
> for example, display a model of the capture skeleton and the playback
> skeleton to help the author decide how to proceed, or even, if the names
> matched, do it automagically.
>
> A Humanoid Motion animation resides in the Humanoid object and for best
> automation, should include enough information to reconstruct the capture
> skeleton hierarchy. In order to establish this baseline, the existing
> Motion node wants the author to transcribe important bvh data into x3d data
> forms and place it within the Humanoid Motion node. This practice also
> tends to help transportability between various typical capture skeletons
> and x3d hanim ‘standard’ skeletons.
>
>
>
>    - Your loa4 idea makes sense if you don't want to ignore….
>
>
>
> I still think the idea behind ‘ignore’ is that if you have more joints and
> data in for the capture skeleton than the playback skeleton can use. The
> author has determined that some of the capture data has to be ignored and
> not sent to playback skeleton, so those joints are labeled with ‘ignore’
> keyword in order to declare that the related data is not to be used. Please
> tell me if this is not what is intended.
>
> If that is the case then the playback skeleton will never know because no
> events are sent to joints that are not there.
>
> If you have more joints in the playback skeleton, then it is ok and no
> capture data needs to be ignored and playback joints that don’t get data
> don’t care and work as if not there.
>
>
>
> Thanks for thinking about this,
>
> Joe
>
>
>
> *From: *GPU Group <gpugroup at gmail.com>
> *Sent: *Wednesday, June 24, 2020 4:33 PM
> *To: *Joseph D Williams <joedwil at earthlink.net>
> *Cc: *Spec Feedback <spec-comment at web3d.org>; x3d at web3d.org
> *Subject: *Re: [x3d] Spec Comment by dougsanden on 19774-2: HAnim Motion
> Capture -V1.0
>
>
>
> My conceptual model is a bit different.
>
> - skeletal joint asks for joint information from MotionData/MotionClip,
> joint by joint when traversing the skeletal joint hierarchy.
>
> Your loa4 idea makes sense if you don't want to ignore.And -depending on
> your implementation, like you say you'd get identity transforms -no joint
> motion- for joints MotionClip doesn't have.
>
> -Doug
>
>
>
> On Wed, Jun 24, 2020 at 5:20 PM Joseph D Williams <joedwil at earthlink.net>
> wrote:
>
>
>    - and they have a brief statement somewhere saying its ignored ie the
>    values field has it, but the humanoid doesn;t.
>    - But they didn't say mathematically what to do about it.
>
>
>
> OK, so there are Motion values for a joint in from the capture skeleton
> but either they do not apply to a Joint in the playback skeleton, or there
> is no corresponding joint in the playback skeleton. Thus, as an author, you
> just want to ignore that set of values in the Motion values field.
>
>
>
> For a typical animation routine, if you send events to a node that is not
> there, you get an error.
>
> If there is a Joint in the capture skeleton that does not appear in the
> playback skeleton, then you don’t try to send events to that joint, because
> it is not there. So, if the Joint is actually present, then that Joint will
> remain in its default orientation.
>
> This is OK, and the skeleton does not mind at all, it is like the Joint is
> not there except it is and may have child Joint hierarchy. Of course in
> that case the parent of the ignored joint controls the child hierarchy. If
> whatever animation device is under the covers thinks it must send data to
> that joint, then don’t use the Motion values, just send  0 0 1 0 each cycle.
>
>
>
> Ignore, means Hey, my capture skeleton has a Joint and I have data for it
> but my playback skeleton does not have that joint. I am trying to import,
> for example, some LOA4 animations into my LOA3 playback skeleton. As an
> author you are choosing to refuse to give your loa3 an update and you must
> confess that fact by using IGNORE in your Motion node list.
>
>
>
> At least that has been my experience, when using animations aimed at a
> higher or lower loa than the playback skeleton. For lower loa playback
> skeleton, just comment out the interpolators and routes for the unused
> Joint nodes. If higher loa playback skeleton, then problems because the
> hierarchy does not care about ignoring intermediate joints. Just don’t send
> data or if you must, just send 0 0 1 0 to the ignored joint.
>
>
>
> This is again why you want to just go ahead and start work with the loa4
> playback skeleton. Because it is ok to ignore it if you don’t have data for
> it. It is always not ok to not send data to something that is not there and
> any browser should tell you and probably should fail if you try to do that.
>
> Thanks,.
>
> Joe
>
>
>
> *From: *GPU Group <gpugroup at gmail.com>
> *Sent: *Wednesday, June 24, 2020 3:33 PM
> *To: *Joseph D Williams <joedwil at earthlink.net>
> *Cc: *Spec Feedback <spec-comment at web3d.org>; x3d at web3d.org
> *Subject: *Re: [x3d] Spec Comment by dougsanden on 19774-2: HAnim Motion
> Capture -V1.0
>
>
>
> The IGNORED is in the Motion AnnexD example scene:
>
>  <HAnimMotion frameCount="392" enabled='true' loop='true' frameTime =
> "0.033333" frameDuration=".033333"
>
>              joints="humanoid_root, l_hip, l_knee, l_talocrural, r_hip,
>
>                    r_knee, r_talocrural, vl5, IGNORED, l_shoulder,
>
>                    l_elbow, l_radiocarpal, IGNORED, r_shoulder, r_elbow,
>
>                    r_radiocarpal, IGNORED, skullbase"
>
> and they have a brief statement somewhere saying its ignored ie the values
> field has it, but the humanoid doesn;t.
>
> But they didn't say mathematically what to do about it. My interpretation
> is that you would accumulate the ignored values as you go down the bvh limb
> tree to get the next joint. If you're working call-by-call, to make sure
> the transform fetcher understands what's been skipped, you woult tell it
> the previous joint you asked for when asking for the next (and it would
> look at the bvh and see you are ignoring some joints)
>
> getNextJointTransform(lastJoint,currentJoint,time,&transform)
>
> something like that. I'm not doing that yet, and haven't proven the theory
> of joint transform accumulation.
>
> The likely reason the AnnexD model didn't seem to mind / looked like its
> bvh animation in blender: the IGNORED values were zeros anyway. I was lucky,
>
> The nature of matching up free downloaded bvh with any loa hanim character
> I have means we;ll be skipping and some and some joints never captured by
> the mocap system / not in the bvh list. For freewrl users, that's OK -
> doesn't need to be perfect, just needs to get us into the game and having
> fun experimenting. .
>
> -Doug
>
>
>
> On Wed, Jun 24, 2020 at 4:18 PM Joseph D Williams <joedwil at earthlink.net>
> wrote:
>
>
>    - - IGNORE - the transform fetcher needs to accumulate the ignored
>    transforms to apply to the next non-ignored joint in the
>
>
>
> Not sure what the transform fetcher does but this is no different than
> having an intermediate joint that is not animated.? In operation, not
> animating a Joint does not cause any problems. That is why it is always
> good to pick the loa4 skeleton for most fun. If a joint is ignored, it is
> just not animated and remains in its default position. Its children may
> still be animated.
>
> Anyway, am I missing something? Ignored just means there is no animation
> driving that Joint. The bigger problem is when you have animation trying to
> drive a joint that is not there. Mostly the browser will tell you that.
>
>
>
>    - No need for the software to complain if bvh doesn't match.
>
>
>
> I think if Motion node cannot find a matching Joint somewhere, then
> failure until you get the list right and all named joints matched up[.
>
> If you look at some sample typical timer/interpolator/route setup and you
> try to drive a joint that is not there or has the different name, then it
> will usually tell you about missing sources or targets. Maybe I don’t
> understand what ignore refers to? What does ignore refer to? A Joint in the
> Humanoid skeleton, a joint in the capture skeleton,  or a set of data for a
> joint in the bvh file?
>
> Thanks,
>
> Joe
>
>
>
>
>
>
>
> *From: *GPU Group <gpugroup at gmail.com>
> *Sent: *Wednesday, June 24, 2020 5:56 AM
> *To: *Joseph D Williams <joedwil at earthlink.net>
> *Cc: *Spec Feedback <spec-comment at web3d.org>; x3d at web3d.org
> *Subject: *Re: [x3d] Spec Comment by dougsanden on 19774-2: HAnim Motion
> Capture -V1.0
>
>
>
> No need for the software to complain if bvh doesn't match.
>
> Already in the HAnim2 specification for Motion they use the IGNORE keyword
> when when HH is skipping a joint the bvh has. Not shown in the spec, but
> likely to happen is the bvh not having a joint that the HH has, what I call
> NOT_IMPLEMENTED, to keep it separate from IGNORE
>
> - IGNORE - the transform fetcher needs to accumulate the ignored
> transforms to apply to the next non-ignored joint in the limb tree I didn't
> do this yet, but should have it somewhere, so it applies also in in the
> original Motion node if there are IGNOREs.
>
> - NOT_IMPLEMENTED (bvh doesn't have the joint) - the HH would get an
> identity transform back for that joint.
>
> -Doug
>
>
>
> On Tue, Jun 23, 2020 at 9:36 PM Joseph D Williams <joedwil at earthlink.net>
> wrote:
>
>
>    - Then one mapping node …
>
>
>
> Currently the Humanoid skeleton declares its active Joint nodes by naming
> each Joint node and by including list of used Joints in the Humanoid joints
> field.
>
> I think the Motion node also declares the joints it wants to use by
> listing in the Motion node.
>
> To my knowledge there is no requirement that the Humanoid joints list be
> in any specific order.
>
> I think the Humanoid Motion joints field needs the list in some order
> relating to the data.
>
> The point is that for Motion to work, it must find the appropriate Joint
> name in the Humanoid joints field.
>
>
>
> My only big point is that both of those lists should look about the same
> (MF strings). If you want a skeleton that is matched to the bvh data, then
> we change the names in the imported bvh to match the names used in the
> skeleton field and enumerated in the Humanoid joints field. Some help could
> be given to an author helping to match the bvh skeleton nomenclature with
> the Humanoid joints. Or if you are really serious about using bvh data,
> then gather enough examples to suggest a ‘typical standard’ bvh skeleton
> and data, then compose a skeleton in the Humanoid skeleton field to match
> and then you might use a ‘typical standard’ Motion fields.
>
>
>
> The main idea of the Humanoid joints field is to list the actual joints
> that are available in the skeleton model. The purpose of the joints list in
> the Motion node is to declare which of those joints will be active in the
> current simulation. In this case, if the capture skeleton is the same as
> the playback skeleton, no problem to just change the data.
>
>
>
> So, the only things the browser needs to figure out is: Do the Motion
> joints match the skeleton joints and complain if not.
>
>
>
> Best Regards and Thanks for thoughts on this.
>
> Joe
>
>
>
> *From: *Spec Feedback <spec-comment at web3d.org>
> *Sent: *Tuesday, June 23, 2020 6:02 AM
> *To: *x3d at web3d.org
> *Subject: *[x3d] Spec Comment by dougsanden on 19774-2: HAnim Motion
> Capture -V1.0
>
>
>
> -- Submitter indicates that this comment may be public: *Yes* --
>
>
>
> Comment on 19774-2: HAnim Motion Capture - V1.0
>
>
>
>
>
>
>
> -----------------
>
> Proposed Explicit Name Mapping node
>
> NameMapping
>
> MFString A []
>
> MFString B []
>
>
>
> Esample:
>
>
>
>
>
> Discussion:
>
> not necessary to have IGNORED or NOT_IMPLEMENTED - that would be the
> default
>
> if not found during lookup.
>
> Then one mapping node can be used for multiple .bvh from various sources.
>
> Putting a mapping node into both HAnimHumanoid HH and HAnimMotionClip/Data
>
> HMC would allow a 2-step lookup:
>
> - HH to loa, loa to HMC
>
> - A previous comment shows the math advantage of 2 step
>
> If no mapping nodes present, browser would assume names are same in HH and
>
> HMC
>
> - if one mapping node in either HH or HMC, then a 1-step lookup is done
>
>
>
>
>
> -----------------
>
>
>
> Submitted on Tuesday, 2020,  June 23 - 7:02am
>
> by dougsanden (dougsanden )
>
> IP: 75.159.18.239
>
>
>
> See: https://www.web3d.org/node/1694/submission/4051
>
>
>
>
>
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