<div style="color:rgb(0,0,0);font-family:arial,sans-serif;font-size:12pt"><p style="margin: 0.1rem 0; line-height: 1.0;">> <span style="color: #000000; font-family: 'Times New Roman'; font-size: medium; white-space: normal; float: none; display: inline;">bone tail should not be child joint center. </span> </p>
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<p style="margin: 0.1rem 0; line-height: 1.0;">Of course it should.</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">A bone tail is the child of the bone head,</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">and the bone head is the same as the</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">parent joint of the bone.</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">The hierarchy is produced when a child bone tail</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">is the same as the parent Joint of a child bone head.</p>
<p style="margin: 0.1rem 0; line-height: 1.0;"> </p>
<p style="margin: 0.1rem 0; line-height: 1.0;">A bone is a typical connection device to make a skeleton.</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">The skeleton consists of a realistic set of bones</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">set in a realistic hierarchy designed to</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">reproduce <span style="font-size: 12pt;">human poses and motions. </span></p>
<p style="margin: 0.1rem 0; line-height: 1.0;"><span style="font-size: 12pt;"> </span></p>
<p style="margin: 0.1rem 0; line-height: 1.0;">A bone has a head which is either the skeleton root </p>
<p style="margin: 0.1rem 0; line-height: 1.0;">or a child anchor location that allows setting</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">the bone orientation and thus the bone tail location </p>
<p style="margin: 0.1rem 0; line-height: 1.0;">by rotation of the x, y, and z axes pivot point</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">at the bone head. </p>
<p style="margin: 0.1rem 0; line-height: 1.0;"> </p>
<p style="margin: 0.1rem 0; line-height: 1.0;">Since animation is produced by rotation of one or a</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">certain set of bone heads, we want to go ahead and</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">just call the head of a bone a Joint. </p>
<p style="margin: 0.1rem 0; line-height: 1.0;">Then, a Joint is connected to another Joint, or</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">an end-effector by a bone, which because</p>
<p style="margin: 0.1rem 0; line-height: 1.0;">there may be other styles of attachment, </p>
<p style="margin: 0.1rem 0; line-height: 1.0;">we call a bone a Segment. </p>
<p style="margin: 0.1rem 0; line-height: 1.0;"> </p>
<p style="margin: 0.1rem 0px; line-height: 1;">While the viewer observes skeletal poses</p>
<p style="margin: 0.1rem 0px; line-height: 1;">as changes in bone position and orientation,</p>
<p style="margin: 0.1rem 0px; line-height: 1;">that motion is actually produced by the character</p>
<p style="margin: 0.1rem 0px; line-height: 1;">using equivalent rotation of an appropriate Joint. </p>
<p style="margin: 0.1rem 0; line-height: 1.0;"> </p>
<p style="margin: 0.1rem 0; line-height: 1.0;">Thanks for the fun with HAnim, </p>
<p style="margin: 0.1rem 0; line-height: 1.0;">Joe</p>
<p style="margin: 0.1rem 0; line-height: 1.0;"> </p>
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<p>-----Original Message-----<br>From: John Carlson <yottzumm@gmail.com><br>Sent: Jan 16, 2025 10:55 PM<br>To: X3D Ecosystem public discussion <x3d-ecosystem@web3d.org>, Katy Schildmeyer KS APPAREL DESIGN <katy@ksappareldesign.com>, Joe D Williams <joedwil@earthlink.net>, Michalis Kamburelis <michalis.kambi@gmail.com>, Vincent Marchetti <vmarchetti@kshell.com>, Carol McDonald <cemd2@comcast.net>, GPU Group <gpugroup@gmail.com><br>Subject: Re: Does this AI program generally look correct?</p>
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<div dir="auto">Here’s another option:</div>
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<div><a href="https://claude.site/artifacts/fa241e9b-1755-4ae6-8bcf-ea4841248b9a">https://claude.site/artifacts/fa241e9b-1755-4ae6-8bcf-ea4841248b9a</a></div>
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<div dir="auto">What these two seem to indicate is that bone tail should not be child joint center. What do you think? Also, since it’s not only the bone head influencing the skin, perhaps we should change the length of the bones I’m loading?</div>
<div dir="auto"> </div>
<div dir="auto">I’m puzzled, because I see a difference in how Claude seems to indicate how bone influences the skin than what you guys have been telling me, but perhaps you guys assumed short bone length?</div>
<div dir="auto"> </div>
<div dir="auto">John </div>
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<div class="gmail_attr" dir="ltr">On Fri, Jan 17, 2025 at 12:42 AM John Carlson <<a href="mailto:yottzumm@gmail.com">yottzumm@gmail.com</a>> wrote:</div>
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<div dir="auto">If we can agree that this generally looks ok, I will try to implement this in the Blender importer: <a href="https://claude.site/artifacts/7c4c15f2-1bde-4da5-9503-f4f25b09016a" target="_blank" rel="noopener">https://claude.site/artifacts/7c4c15f2-1bde-4da5-9503-f4f25b09016a</a></div>
<div dir="auto"> </div>
<div dir="auto">I realize the bone.tail should probably be the child joint center.</div>
<div dir="auto"> </div>
<div dir="auto">I do not yet know what i am doing wrong, but my focus will be shifting to animation import after export is done to my satisfaction.</div>
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