[X3D-Public] Importing H-Anim Avatars into Seamless3d 2.151

Joe D Williams joedwil at earthlink.net
Mon May 18 00:21:12 PDT 2009

> You may be interested to know the main challenge for me to get 
> seamless 2.151 to import your file was to make seamless be able to 
> deal with unused vertices which is the sort of thing you don't 
> expect output from a program but is the sort of thing a human will 
> do.

If you messed with my vertices, then I won't be happy. Each one of 
them was there for a purpose, just because it was not connected in 
what I put out there is no reason to drop it. Now all the numbers are 
different and I'm not sure I would be ready for that. .

> This posed a problem because seamless natively has to account for 
> every vertex (every vertex must be owned by a part/bone), so 
> seamless now deletes all unused vertices when converting.

That sounds OK, if I select it. But what a cascade! drop vert, change 
skin mesh indexes and thus binding indices, a big step but maybe 
simple to test.

> In Seamless, I was able to see some of your pivot points were not in 
> the correct location, easy to spot in a graphical environment but 
> easily hidden when using only a text editor.

Those 'pivot points' are called 'joint centers' and if you moved any 
of them automagically to match some exact model you have as your 
character, then you are wrong. In the normative sense there is no 
'correct' location for a joint center and only a reasonable example is 
given in the standard. Only the hierarchy (what is connected to where) 
and the joint names are given as normative. I used reasonable 
considerations for joint centers in my model so don'rt mess them them, 
Please. .

> The pivot point for the selected part is displayed in Seamless's 3d 
> window as a small yellow sphere (or dot).
To select a part, click on the part node (that looks like a bone) in 
the scene tree window.
Also if you click a vertex, the part that owns the vertex will be 
selected and shown selected in the scene tree window.

Yes, I am sure all that is wonderful. Just don't go demanding to me 
where a particular joint center should go.
Maybe I will get a chance to see what actually happened. In future 
examples I want to apply more extensive animations to the character. 
It may be interesting to see what happens to skin when your progg 
moves a joint center for me.

> Can you please upload your avatar so that I can reference it 
> elsewhere on the net Joe?

OK, look at:
X3D H-Anim Examples

It is the first one in the list. Actually, I have worked through many 
levels of complexity to get this thing to where it is, which is just 
the most simple example I have.

> It is a valuable example because it's hand coded,

Thank You. Hoping for the combination of hand coded and human 
Best read using simplist text editor with auto line wrap turned off.
The coding is important in the example, to give the thing a chance of 
being readable.
At least the character joint hierarchy is visible. The joint locations 
are defined with strong reference to the LOA3 example in the H-Anim 
spec. Further, some joint centers, Segment lengths, Site locations, 
and some skin vertices are adjusted with respect to the NIST model 
MANGLOSS skin figure that I found. Since the skin vertices are defined 
relative to the joint centers, just understand that the joint centers 
and skin vertices are in my domain, not necessarily 'your' or anyoune 
else's model stored somewhere.

Other requirements, like joints with the wrong name, or connected with 
the 'wrong' segment, and SItes attched to the wrong segment may be 
helpful to point out  All that sort of stuff is in the spec, but when 
we start moving joint centers for me, then that is uncalled for. For 
instance, did you move any hand/finger joint centers? If so, that skin 
may not really work anymore in that area.

> has the complete set of H-Anim joints

Yes, I think all the LOA3 joints, highest level of current spec 
articulation, are there.
Complex skeleton and simple skin. ,

> and there are so few open H-Anim examples online that work and are 
> legal!

Is some 'legal' thing making a barrier to X3D H-Anim?
If so, let's figure out what it is.
With modern tools like you are describing, this stuff is getting 
fairly easy and animating the X3D Humanoid is very simple and natural 
when you get the joints set up normally.

> best wishes
> thyme
> www.seamless3d.com

Thanks for looking and Best Regards,

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