<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Holger, I agree with you, after my carefui examination of a 3-D printing of this:<div><br></div><div><img src="cid:A15350D7-18AB-45E7-A047-BE4EA5DCD37B" alt="corks.jpg"></div><div><br><div>Described as an extrusion, this would be an extrusion of an equilateral triangle around a closed loop, with a rotation of</div><div>the cross-section by 120 degrees over the loop.</div><div><br></div><div>Vince</div><div><br></div><div><br></div><div><br><blockquote type="cite"><div>On Aug 2, 2025, at 10:53 AM, Holger Seelig via X3D-Ecosystem <x3d-ecosystem@web3d.org> wrote:</div><br class="Apple-interchange-newline"><div><meta http-equiv="content-type" content="text/html; charset=utf-8"><div style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Sorry, but this is not a Möbius strip (denote the point above the o), because the rotation of the strip (crossSection) is 360 degrees, but there should <span style="caret-color: rgb(0, 0, 0);">only </span>be a rotation about 180 degrees.<div><br></div><div>The orientation field of the Extrusion node should <span style="caret-color: rgb(0, 0, 0);">better</span><span style="caret-color: rgb(0, 0, 0);"> </span>hold these values:</div><div><br></div><div><div>0 1 0 0,</div><div>0 1 0 0.130899693899575,</div><div>0 1 0 0.261799387799149,</div><div>0 1 0 0.392699081698724,</div><div>0 1 0 0.523598775598299,</div><div>0 1 0 0.654498469497874,</div><div>0 1 0 0.785398163397448,</div><div>0 1 0 0.916297857297023,</div><div>0 1 0 1.0471975511966,</div><div>0 1 0 1.17809724509617,</div><div>0 1 0 1.30899693899575,</div><div>0 1 0 1.43989663289532,</div><div>0 1 0 1.5707963267949,</div><div>0 1 0 1.70169602069447,</div><div>0 1 0 1.83259571459405,</div><div>0 1 0 1.96349540849362,</div><div>0 1 0 2.0943951023932,</div><div>0 1 0 2.22529479629277,</div><div>0 1 0 2.35619449019235,</div><div>0 1 0 2.48709418409192,</div><div>0 1 0 2.61799387799149,</div><div>0 1 0 2.74889357189107,</div><div>0 1 0 2.87979326579064,</div><div>0 1 0 3.01069295969022,</div><div>0 1 0 3.14159265358979</div></div><div><br></div><div><span style="caret-color: rgb(0, 0, 0);">Follow a plane or a edge of the strip a</span>nd you will see that now it has only one of them.</div><div><br></div><div>Here is a direct comparison of both of the strips:</div><div><a href="https://create3000.github.io/x_ite/playground/?url=https://create3000.github.io/Library/Tests/Components/Extrusion/M%C3%B6bius.x3d">https://create3000.github.io/x_ite/playground/?url=https://create3000.github.io/Library/Tests/Components/Extrusion/M%C3%B6bius.x3d</a></div><div><br></div><div>Please also have a look at the Wikipedia page:</div><div><a href="https://en.wikipedia.org/wiki/M%C3%B6bius_strip">https://en.wikipedia.org/wiki/M%C3%B6bius_strip</a></div><div><br></div><div>Best regards,</div><div>Holger</div><div><br id="lineBreakAtBeginningOfMessage"><div>
<meta charset="UTF-8"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div dir="auto" style="text-align: start; text-indent: 0px; overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;">—</div><div style="caret-color: rgb(0, 0, 0); letter-spacing: normal; text-transform: none; white-space: normal; word-spacing: 0px; text-decoration: none; -webkit-text-stroke-width: 0px;">Holger Seelig<br>holger.seelig@yahoo.de<br><br></div></div></div></div></div></div></div></div></div></div></div></div>
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<div><br><blockquote type="cite"><div>Am 01.08.2025 um 20:15 schrieb Don Brutzman via X3D-Ecosystem <x3d-ecosystem@web3d.org>:</div><br class="Apple-interchange-newline"><div><div dir="ltr">Online, open source, in version control at SourceForge:<div><ul><li>X3D Example Archives: X3D4AM, X3D for Advanced Modeling, Geometric Shapes, Mobius Extrusion</li><li>Mobius (or Mobius) is a surface with only one side and only one boundary component.</li><li><a href="https://www.web3d.org/x3d/content/X3dForAdvancedModeling/GeometricShapes/MobiusExtrusionIndex.html">https://www.web3d.org/x3d/content/X3dForAdvancedModeling/GeometricShapes/MobiusExtrusionIndex.html</a></li></ul><div>Vince, didn't that get derived from something you originally did? Apologies if further provenance information is needed, if so then please advise and let's add it.</div><div><br></div><div>all the best, Don</div></div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Fri, Aug 1, 2025 at 5:35 AM Vincent Marchetti via X3D-Ecosystem <<a href="mailto:x3d-ecosystem@web3d.org">x3d-ecosystem@web3d.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">John<br>
<br>
Yes, you can use the file for a ticket submission<br>
<br>
Vince Marchetti<br>
<br>
<br>
> On Aug 1, 2025, at 7:55 AM, John Carlson via X3D-Ecosystem <<a href="mailto:x3d-ecosystem@web3d.org" target="_blank">x3d-ecosystem@web3d.org</a>> wrote:<br>
> <br>
> Vince,<br>
> <br>
> Can I release mobius.x3d to the x3d tickets on sourceforge? I sent you email, probably too early!<br>
> <br>
> I’d like to get X3dToJson.xslt fixed, and stuff added to the X3DJSAIL DOM loader. Apparently, LineSets and NurbsPatchSurface need to be listed in a humoungous set of if then else if statements as children of Shape. I don’t know why they aren’t in dispatch table(s), probably the branch prediction on the CPU is wild. Maybe Java’s Jackson APIs could supplant it.<br>
> <br>
> Here are a few of my type and method lookup tables. They aren’t perfect!<br>
> <br>
> Michalis, could I use these for data driving the JSON to X3DNode thing in Pascal? At least a first cut?<br>
> <br>
> <a href="https://github.com/coderextreme/X3DJSONLD/blob/master/src/main/node/fieldTypes.js" rel="noreferrer" target="_blank">https://github.com/coderextreme/X3DJSONLD/blob/master/src/main/node/fieldTypes.js</a><br>
> <br>
> <a href="https://github.com/coderextreme/X3DJSONLD/blob/master/src/main/node/mapToMethod.js" rel="noreferrer" target="_blank">https://github.com/coderextreme/X3DJSONLD/blob/master/src/main/node/mapToMethod.js</a><br>
> <br>
> <br>
> <a href="https://github.com/coderextreme/X3DJSONLD/blob/master/src/main/node/mapToMethod2.js" rel="noreferrer" target="_blank">https://github.com/coderextreme/X3DJSONLD/blob/master/src/main/node/mapToMethod2.js</a><br>
> <br>
> Overrides the former.<br>
> <br>
> <br>
> Thanks,<br>
> <br>
> John<br>
> -- <br>
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