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<div class="moz-cite-prefix">On 11/11/2016 7:40 AM, doug sanden
wrote:<br>
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Would like to see more goodies in HAnim / Anim.
When implementing hanim in freewrl I was shocked by how little work the web3d browser does, and how much work is left for the content developer to do. For example IK. Q. Should we have a general IK solver node? Or other nodes to lighten the burden on content developers? Joe mentioned something about assigning joint weights automatically. Is that a node, or option in node?</pre>
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Um, why? <br>
X3D is not an animation application. It is a format and a run-time.
There are already a number of animation applications that handle
forward and reverse kinematics. X3D browsers (for the most part)
cannot handle deformable skin. There may be some more advanced
applications where it would be really nice to have IK, but right now
X3D can't take baby steps. Content developers (from the art side)
want to control the animation, it's programmers who want a node that
says "walk" so they don't have to figure out how to do that
animation. <br>
Okay, so the above is a bit of a generalization; but there is so
much to do with animation that we need to focus on getting a great
foundation for the basics first.<br>
<br>
<br>
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I'm not sure I understand the difference between maya and blender when it comes to root nodes. Isn't that something an exporter could add, if missing?
...</pre>
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<br>
When rigging a model in Maya, you start with a single joint - a
naked joint. You add another joint (making a "virtual" bone). This
is the root structure of the model. You move the first joint and the
entire model moves.<br>
<br>
In Blender you start with a pair of joints and build from there. <br>
<br>
I haven't worked enough with either of these packages to form an
opinion on this. A joint always defines movement in relation to its
parent; so a single joint can't define anything -- it's just a
point. OTOH, it is symmetric to have everything go down to a single
point. It's sort of like the fill-in squares game. Blender requires
you to draw a line, Maya allows you to first pick a point.<br>
<br>
Another thing I don't understand is scale. Given two points (joints)
there is a line connecting them. This is the 0 rotation. Moving one
point defines a rotation from the 0 to the current position. The
distance between the points can also change. So where does scale
come in? You can't scale-up/down a point. You can't scale the
perpendicular size of the connecting line. You can only scale the
distance, but that is the same a changing the translation.
Alternatively, perhaps rotation and (distance)-scale should be kept
and translation tossed. There are not as many degrees of freedom as
there are quantities trying to specify the details.<br>
<br>
<br>
<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>
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