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<div class="moz-cite-prefix">This may not be easy to read. The
important part is X3D needs to support deformable skin at the
basic animation level (or don't bother to support animated
models). If X3D has that capability, what should be in the H-Anim
spec.<br>
<br>
<br>
<br>
</div>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
----- Original Message ----- From: "Leonard Daly"
<a class="moz-txt-link-rfc2396E" href="mailto:Leonard.Daly@realism.com"><Leonard.Daly@realism.com></a>
<br>
To: "X3D Public" <a class="moz-txt-link-rfc2396E" href="mailto:x3d-public@web3d.org"><x3d-public@web3d.org></a>
<br>
Sent: Thursday, October 13, 2016 10:39 AM
<br>
Subject: [x3d-public] What is H-Anim?
<br>
<br>
<br>
<blockquote type="cite">From reading H-Anim in detail (especially
Part 1), it appears to me
<br>
that it is primarily doing two things
<br>
</blockquote>
<br>
Where would you get the idea that HAnim does not do deformable
skin?
<br>
</blockquote>
<br>
Where did you get the idea that I said it doesn't? In fact, I
explicitly state that it does do that.<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
<blockquote type="cite">
<br>
1) Defining animation with deformable skin
<br>
<br>
</blockquote>
<br>
I would say it is defining a 'standard' skeleton with a 'standard'
pose that can use geometry as children of segments or a deformable
skin that is a child of the humanoid. Either or both segment
geometry and/or skin geometry can be used. The segment geometry is
animated when the segments move by animating the rotation of
joints in the skeleton hierarchy. Skin is animated by weighted
displacement of individual mesh vertices according to individual
or multiple joint rotations.
<br>
</blockquote>
<br>
Animation of deformable skin is industry standard operation. It is
not unique to 3D humans or humanoids.<br>
<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
<blockquote type="cite">
<br>
2) Define bone definition and naming for humanoids.
<br>
<br>
</blockquote>
<br>
Yes we have standardized names and example 'human' space
dimensions for Joints, Segments, and Sites
<br>
We don't call it a bone, we call the bone a segment.
<br>
<br>
<blockquote type="cite">
<br>
I noted that
<br>
humanoids (as defined in the spec 4.2.1) are not required to
have the
<br>
normal human-like appendages (1 head, 2 arms, 2 legs)
<br>
</blockquote>
<br>
tha spec humanoid is one of 5 defined LOAs. All LOA choices
include site locations for all appendages but may not include the
complete skeketon
<br>
</blockquote>
<br>
It may be a complete skeleton, just with 4 arms, 3 legs, and 2
heads. That is allowed in the spec.<br>
<br>
<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
<blockquote type="cite">[<a class="moz-txt-link-freetext" href="http://www.web3d.org/documents/specifications/19774">http://www.web3d.org/documents/specifications/19774</a>-
<br>
1/V2.0/HAnim/concepts.html#HAnimFiguresOverview]
<br>
<br>
</blockquote>
<br>
That is just an isolated paragraph about the versatility of the
basic hierarchal joint model. Besides, your comment is based on a
paragraph that has had no vetting this round. To study the HAnim,
you should base it on V1.0 and figure that the CD V2.0 for Part 1
is a bit scrambled and incomplete at this point relative to V1.0.
<br>
</blockquote>
<br>
V1 is over 10 years old. I don't think you want to be comparing
current industry standards to something that was done isolated from
industry 10 years ago. <br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
All other information is clear that the target is a humanoid
figure with a level of articulation that depends upon the number
and hierarchy of the joints.
<br>
<br>
<blockquote type="cite">
<br>
If X3D were to included deformable skin animation as an
intrinsic part
<br>
of the X3D specification, ...
<br>
</blockquote>
<br>
it already does
<br>
</blockquote>
<br>
Only if the H-Anim component is used. I stated an "intrinsic"
meaning at the base level of animations.<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
<blockquote type="cite"> ... would #1 be required?
<br>
<br>
</blockquote>
<br>
Not sure what you mean. Animation of a continious mesh deformable
skin according to joint rotation is one feature of HAnim. Another
tool for deformable geometry is the DIsplacer node. All big time
authoring tools do these, although for many the skin animation
binding target is illustrated as a bone. No difference.
<br>
</blockquote>
<br>
<br>
I mean for all objects, not just those declared H-Anim.<br>
<br>
<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">.
<br>
<blockquote type="cite">
<br>
If not, that leaves #2. It seems to me that this section is
optional
<br>
<br>
</blockquote>
<br>
Hey, a general concept: To have deformable skin, you use a
skeleton. If not, then that technology is not avaliable to X3D. Or
else you are mistaking calling the dragging lumps of 'skin'
geometry not connected to a skeleton around from keyframe to
keyframe as skin animation. That is not the 'standard' sort of
skin animation we do.
<br>
</blockquote>
<br>
<br>
Skeletons and bones do not imply a humanoid. They can be used for
all animation, including trees, animals (even octopus).<br>
<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
<blockquote type="cite">based on references in the document to
"are common", "generally
<br>
categorize", "may have", "model specific". It seems that if one
is
<br>
modeling a human (not humanoid), then this structure should be
used; but
<br>
if not a human, the the variations are endless.
<br>
<br>
</blockquote>
<br>
True, the variations are endless, like real life except for life
there is an end. However, we are aiming at a 'standard' humanoid
dimensioned in 'human' space having a realistic skelton that can
use 'standard' animations.
<br>
</blockquote>
<br>
So are you saying that this is just a specification for defining how
humanoids are rigged and animated?<br>
<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
The actual geometry used to produce surface features of the model
includes any sort of X3D geomentry. For skin we seem to do best
with an indexed geometry since for deformable skin animation we
need to know the order of appearance in the user code of each
vertex of the skin field.
<br>
</blockquote>
<br>
Not really, that's just the way the implementation did it. The
important part is to know how much weight each bone exerts on a skin
vertex. How that is done is really implementation dependent. The
spec may state a certain manner because it is easier to handle, but
it is not a requirement of the algorithms.<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
<blockquote type="cite">
<br>
I think the document needs an improved focus
<br>
<br>
</blockquote>
<br>
True in part. Mostly it needs consolidation of important skeleton
realtionships and some better examples.
<br>
<br>
<blockquote type="cite">
<br>
and close work with X3D WG
<br>
to determine if deformable skin animation is to be included in a
future
<br>
version of X3D.
<br>
<br>
</blockquote>
<br>
Too late, the horse is out of the barn. We do it the way everyone
does it. It already is included. The document is much at fault for
you to miss that. Look at the skinCoordIndex and skinCoordWeight
fields of the Joint and their descriptions.
<br>
<br>
Why not actually look at user code of some examples and actually
look at some examples of this humanoid really running?
<br>
</blockquote>
<br>
Because I am looking at a much bigger picture than a particular
implementation or example. It is important to get the big picture
right or everything else underneath it will be a kludge. The
document does not use industry standard terminology and notation. It
makes general statements about what is required. Perhaps that is the
fault of this version of the document; but it is very important to
get the big picture right.<br>
<br>
<br>
<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">See attached. Please look at the user code also. Runs
best in BS Contact free.
<br>
Sorry, as far as I know X3DOM don't do skin yet.
<br>
Please tell me what you think.
<br>
<br>
I agree with your recommendation that the X3D working group should
look at the standard, but since deformable skin animation is
included in V1.0 and demonstrated by multiple X3D browsers, please
pick another item upon which we should make a detailed
determination.
<br>
<br>
My comment along these lines is that HAnim seems to need at least
two support levels:
<br>
1 is just segment geometry and
<br>
2 is add skin geometry.
<br>
because implementing 2 seems to be a large step up for some
browsers
<br>
</blockquote>
<br>
That's the fault of the browsers and the spec for not pushing them.
Blender does it, Maya does it, Unity does it, Unreal does it, (I
could add other examples here). Deformable skin needs to be part of
X3D V4. If it's not; there probably is not much purpose in
supporting anything but static models. Life is flexible. if X3D is
going to model that, it needs to be flexible too.<br>
<br>
<br>
Leonard Daly<br>
<br>
<br>
<blockquote
cite="mid:0C1DE171EA1F41B59C51810CFBE92A6A@joe1446a4150a8"
type="cite">
<br>
Thanks,
<br>
Joe
<br>
<br>
Can't wait to see your comments on Part 2.
<br>
<br>
<br>
<blockquote type="cite">
<br>
<br>
-- <br>
*Leonard Daly*
<br>
3D Systems & Cloud Consultant
<br>
LA ACM SIGGRAPH Chair
<br>
President, Daly Realism - /Creating the Future/
<br>
<br>
</blockquote>
<br>
</blockquote>
<br>
<p><br>
</p>
<div class="moz-signature">-- <br>
<font class="tahoma,arial,helvetica san serif" color="#333366">
<font size="+1"><b>Leonard Daly</b></font><br>
3D Systems & Cloud Consultant<br>
LA ACM SIGGRAPH Chair<br>
President, Daly Realism - <i>Creating the Future</i>
</font></div>
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