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<p class="MsoNormal">Robert,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Are you suggesting that I compute the world space normal in the application and pass it to the shader? I absolutely need world space coordinates. If so, how would I get the normal of the triangle before evaluating the shader?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">----------------------------------------<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">Marlin Rowley<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">Software Engineer, Staff<o:p></o:p></span></p>
<p class="MsoNormal"><img width="156" height="40" style="width:1.625in;height:.4166in" id="Picture_x0020_1" src="cid:image001.jpg@01D4190A.784AC380" alt="cid:image002.jpg@01D39374.DEC5A2E0"><span style="font-size:10.0pt;font-family:"Times New Roman",serif;color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#1F497D">Missiles and Fire Control</span></i><span style="color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">972-603-1931 (office)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">214-926-0622 (mobile)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><a href="mailto:marlin.r.rowley@lmco.com"><span style="color:#0563C1">marlin.r.rowley@lmco.com</span></a></span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b>From:</b> osg-users <osg-users-bounces@lists.openscenegraph.org>
<b>On Behalf Of </b>Robert Osfield<br>
<b>Sent:</b> Wednesday, July 11, 2018 11:26 AM<br>
<b>To:</b> OpenSceneGraph Users <osg-users@lists.openscenegraph.org><br>
<b>Subject:</b> EXTERNAL: Re: [osg-users] World space normal.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Hi Marlin,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">It can be done, but I strongly recommend that you don't go transforming vertex or normal data into world coordinates in the shader. I know there are some published algorithms that do this but it's a really bad practice and you shouldn't
follow it as precision issues on only proper dataset will cause mayhem - the do the cals in world coordinates only for datasets with a local origin, it's just a mess for any real-word datasets.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Cheers,<o:p></o:p></p>
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<p class="MsoNormal">Robert.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Wed, 11 Jul 2018 at 14:17, Rowley, Marlin R <<a href="mailto:marlin.r.rowley@lmco.com">marlin.r.rowley@lmco.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I have a world space vertex computed as follows:<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">WorldVertex = osg_ViewMatrixInverse * gl_ModelViewMatrix * aVertex;<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I would like to get the world space normal from this vertex. Is there an equivalent osg_* matrix that does the same thing?<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I tried this:<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">NormalWorld = gl_NormalMatrix * gl_Normal;
<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">But I know that is only putting the normal in view space.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">----------------------------------------</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">Marlin Rowley</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">Software Engineer, Staff</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><img border="0" width="156" height="40" style="width:1.625in;height:.4166in" id="m_-6051910564818734405Picture_x0020_1" src="cid:image001.jpg@01D418ED.163BF190" alt="cid:image002.jpg@01D39374.DEC5A2E0"><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><i><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#1F497D">Missiles and Fire Control</span></i><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">972-603-1931 (office)</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">214-926-0622 (mobile)</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif"><a href="mailto:marlin.r.rowley@lmco.com" target="_blank"><span style="color:#0563C1">marlin.r.rowley@lmco.com</span></a></span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal">_______________________________________________<br>
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