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<p class="MsoNormal">Historically in X3D3 light intensity values have been bounded [0,1] inclusive. While performing regression testing found an unhandled example of <DirectionalLight global='true' intensity='3'/> derived from a glTF model conversion.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<ul style="margin-top:0in" type="disc">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">GlamVelvetSofa.x3d which was converted by view3dscene from glTF example:<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">https://github.com/KhronosGroup/glTF-Sample-Models/blob/master/2.0/GlamVelvetSofa/glTF/GlamVelvetSofa.gltf<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">https://X3dGraphics.com/examples/X3dForAdvancedModeling/GltfSampleModels/GlamVelvetSofa.x3d<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">https://X3dGraphics.com/examples/X3dForAdvancedModeling/GltfSampleModels/GlamVelvetSofaIndex.html<o:p></o:p></li></ul>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As part of X3D4 Architecture, all light intensity values are now allowed to have any non-negative value.<o:p></o:p></p>
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<p class="MsoNormal" style="border:none;padding:0in"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<ul style="margin-top:0in" type="disc">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">X3D 4, Lighting component, 17.3.1 X3DLightNode<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/lighting.html#X3DLightNode<o:p></o:p></li></ul>
<p class="MsoNormal" style="margin-top:13.5pt;mso-margin-bottom-alt:auto"><b><span style="font-size:15.5pt;font-family:"Verdana",sans-serif;color:black">17.3.1 <i>X3DLightNode</i><o:p></o:p></span></b></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black">X3DLightNode : X3DChildNode {
<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black"> SFFloat [in,out] ambientIntensity 0 [0,1]<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black"> SFColor [in,out] color 1 1 1 [0,1]<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black"> SFBool [in,out] global FALSE<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black">
<span style="background:lightcyan">SFFloat [in,out] intensity 1 [0,∞)</span>
<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black"> SFNode [in,out] metadata NULL [X3DMetadataObject]<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black"> SFBool [in,out] on TRUE<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black"> SFBool [in,out] shadows FALSE<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black"> SFFloat [in,out] shadowIntensity 1 [0,1]<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:18.75pt"><span style="font-size:8.5pt;font-family:"Courier New";color:black">}<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Also<o:p></o:p></p>
<ul style="margin-top:0in" type="disc">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">17.2.1 Light source semantics, 17.2.1.1 Overview<o:p></o:p></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo1">https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/lighting.html#LightSourceSemantics<o:p></o:p></li></ul>
<p><span style="font-size:12.0pt;font-family:"Verdana",sans-serif;color:black">Any node used as a source of illumination is derived from <i><a href="https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/lighting.html#X3DLightNode">X3DLightNode</a></i>.
All light sources contain an <i>intensity</i>, a <i>color</i>, and an <i>ambientIntensity</i> field. The <i>intensity</i> field specifies the brightness of the direct emission from the light, and the <i>ambientIntensity</i> specifies the intensity of the ambient
emission from the light. Light intensity may range from 0.0 (no light emission) to infinity. The <i>color</i> field specifies the spectral colour properties of both the direct and ambient light emission as an RGB value. The on field specifies whether the light
is enabled or disabled. If the value is </span><span class="code"><span style="font-size:10.5pt;font-family:"Courier New";color:black">FALSE</span></span><span style="font-size:12.0pt;font-family:"Verdana",sans-serif;color:black">, the light is disabled and
will not affect any nodes in the scene. If the value is </span><span class="code"><span style="font-size:10.5pt;font-family:"Courier New";color:black">TRUE</span></span><span style="font-size:12.0pt;font-family:"Verdana",sans-serif;color:black">, the light
will affect other nodes according to the <a href="https://www.web3d.org/specifications/X3Dv4Draft/ISO-IEC19775-1v4-CD1/Part01/components/lighting.html#ScopingOfLights">17.2.1.2 Scoping of lights</a>.<o:p></o:p></span></p>
<p class="MsoNormal" style="background:lightcyan;font-variant-ligatures: normal;font-variant-caps: normal;orphans: 2;text-align:start;widows: 2;-webkit-text-stroke-width: 0px;text-decoration-thickness: initial;text-decoration-style: initial;text-decoration-color: initial;word-spacing:0px">
<span style="font-size:12.0pt;font-family:"Verdana",sans-serif;color:black">Typically lighting <i>intensity</i> values are within range [0,1] for consistent composability of multiple scenes with independent lights.<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">1. Dick, I think we need to check the above wording to avoid ambiguity since ambientIntensity and shadowIntensity remain in range [0,1]<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">2. Have relaxed upper bounds on lighting intensity in X3D4 schema and X3DUOM.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Since the restriction of [0,1] appears many times, an internal type name is used. As indicated in Schema changelog entry which follows, am renaming it for clarity and correctness. This has no effect on specification, since it is not an
official data type, but it does help X3D XML Schema and X3DUOM-derived codebases be exactly consistent and correct.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">- rename intensityType as unitIntervalType for correctness<o:p></o:p></p>
<p class="MsoNormal"> <a href="https://en.wikipedia.org/wiki/Unit_interval">https://en.wikipedia.org/wiki/Unit_interval</a><o:p></o:p></p>
<p class="MsoNormal">- (v4.0) relax upper bounds on light intervals, previously [0,1] now [0,infinity]<o:p></o:p></p>
<p class="MsoNormal"> which matches glTF Physically Based Rendering (PBR) parameters<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This change will ripple through various APIs and stylesheets in the next few days. So far, deployed in X3D XML Schema, X3DUOM and X3DJSAIL.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Confirmation/correction comments and questions are always welcome. Once again thanks to Michalis Kamburelis for his rigorous design alignment of X3D with glTF.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Have intense fun with X3D! 8)<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">all the best, Don<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">-- <o:p>
</o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">Don Brutzman Naval Postgraduate School, Code USW/Br brutzman@nps.edu<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">Watkins 270, MOVES Institute, Monterey CA 93943-5000 USA +1.831.656.2149<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">X3D graphics, virtual worlds, Navy robotics https://</span>
<span style="font-size:10.0pt;font-family:"Courier New"">faculty.nps.edu/brutzman<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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