<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
p.m-1109494319870621309m-9175488166943601978msolistparagraph, li.m-1109494319870621309m-9175488166943601978msolistparagraph, div.m-1109494319870621309m-9175488166943601978msolistparagraph
{mso-style-name:m_-1109494319870621309m_-9175488166943601978msolistparagraph;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
color:black;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:1372613687;
mso-list-template-ids:-1;}
@list l0:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level2
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:1.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level3
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:1.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level4
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:2.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level5
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:2.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level6
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:3.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level7
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:3.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level8
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:4.0in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l0:level9
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:4.5in;
mso-level-number-position:left;
text-indent:-.25in;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
ol
{margin-bottom:0in;}
ul
{margin-bottom:0in;}
--></style></head><body lang=EN-US link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal>I meant simple standard gltf use of 16 joints per vertex with unused weights set to 0.</p><p class=MsoNormal>Joe</p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Sent from <a href="https://go.microsoft.com/fwlink/?LinkId=550986">Mail</a> for Windows 10</p><p class=MsoNormal><o:p> </o:p></p><div style='mso-element:para-border-div;border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='border:none;padding:0in'><b>From: </b><a href="mailto:joedwil@earthlink.net">Joseph D Williams</a><br><b>Sent: </b>Tuesday, December 11, 2018 8:11 AM<br><b>To: </b><a href="mailto:Leonard.Daly@realism.com">Leonard Daly</a>; <a href="mailto:x3d-public@web3d.org">x3d-public@web3d.org</a><br><b>Subject: </b>Re: [x3d-public] glTF - HAnim conversion</p></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>What was the detail that (for the convenience of the hardware) ‘always’ used 19 joints per vertex with unused joints weights set to 0?<o:p></o:p></p><p class=MsoNormal>I thought I have heard that a few times.<o:p></o:p></p><p class=MsoNormal>Joe<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b>From: </b><a href="mailto:Leonard.Daly@realism.com">Leonard Daly</a><br><b>Sent: </b>Tuesday, December 11, 2018 7:38 AM<br><b>To: </b><a href="mailto:x3d-public@web3d.org">x3d-public@web3d.org</a><br><b>Subject: </b>Re: [x3d-public] glTF - HAnim conversion<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><div><div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'><div><div><ul type=disc><li class=m-1109494319870621309m-9175488166943601978msolistparagraph style='mso-list:l0 level1 lfo1'>glTF associates a joint or<o:p></o:p></li></ul><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:40.8pt'>multiple joints to each vertex of a mesh <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:40.8pt'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:40.8pt'>yes, gltf apparently associates ‘all’ or always at least 16(?) joints (and weights) with each vertex. That means there is feature called a vertex that has a list of joints and weights associated with it. There is one of these for each vertex, all listing all joints and weights.<o:p></o:p></p></div></div></blockquote></div></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Yes. For glTF, the minimum a compliant viewer needs to support is 4 joints (out of many) per vertex. A viewer is free to ignore additional joints, with the lowest weights.<o:p></o:p></p></div></div></blockquote><p class=MsoNormal style='margin-bottom:12.0pt'><br><br>Standard practice in the animation industry is to use a maximum of four joints per skin vertex. There is no standard that limits this. Practical experience from rigging (attaching vertices to joints (aka bones)) and performance indicates that (for the most part) four is the most that is needed. In many cases it is only two.<br><br>So for practical purposes, the limit in glTF does not impact what can be done.<o:p></o:p></p><p class=MsoNormal>-- <br><b><span style='font-size:13.5pt;color:#333366'>Leonard Daly</span></b><span style='color:#333366'><br>3D Systems & Cloud Consultant<br>LA ACM SIGGRAPH Past Chair<br>President, Daly Realism - <i>Creating the Future</i> </span><o:p></o:p></p><p class=MsoNormal><span style='color:black'><o:p> </o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>