<div dir="ltr">There is nothing magical about what the OSG does. It just loads data, sets up the camera view and project matrices that you application sets and passes them to OpenGL without any modifications.<div><br></div><div>Now if you are loading data for standard OSG plugoins like OpenFlight then these models will be loaded in world coords where Z is up, Y is north, X is east, and the OSG camera manipulators default to this convention so they set the view so it looks north, Z up, X to the right.</div><div><br></div><div>OpenGL coordinate frame is not a fixed thing, the coordinate frame that objects are in depends upon their modelview matrix. The only thing that is fixed in OpenGL coordinate frames is the eye coordinate frame that is Y up, X to the right and Z out from the screen. Eye coordinates and world coordinates are a very different thing though and you shouldn't conflate the two. It sounds like to me like you assume that OpenGL eye coordinates is what all OpenGL coordinate fame are. I'm afraid this is just a common misconception about coordinate frames in OpenGL and real time graphics in general.</div><div><br></div><div>As to what to suggest for you it's difficult to guess what you do and don't know about OpenGL, the OSG and graphics in general, so it's hard to know where to start when explain stuff.</div><div><br></div><div>Robert.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On 10 April 2018 at 21:03, Rowley, Marlin R <span dir="ltr"><<a href="mailto:marlin.r.rowley@lmco.com" target="_blank">marlin.r.rowley@lmco.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal">Hello,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I’m very confused by this coordinate system. It appears that our conventional left-handed and right-handed systems are NOT used, which causes havoc with the OpenGL coordinate frame.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">It seems like getting the view matrix at the origin looking down what would be a left-handed +z-axis but rotated 90-degress about the x-axis so that z is pointing up seems to be the coordinate frame.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">In a function call for getting the view matrix from a camera, for example. You get these values for the matrix (assuming it’s
<b><u>column-major</u></b> order)<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Mat[2] : [0, -1, 0] <span style="font-family:Wingdings">ç</span> LOOK<u></u><u></u></p>
<p class="MsoNormal">Mat[1]: [0, 0, 1] <span style="font-family:Wingdings">ç</span>UP<u></u><u></u></p>
<p class="MsoNormal">Mat[0]: [1, 0, 0] <span style="font-family:Wingdings">ç</span> RIGHT<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">This is confusing me with getting transforms and moving them into the vertex shaders.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">-M <u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1f497d">------------------------------<wbr>----------<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1f497d">Marlin Rowley<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1f497d">Software Engineer, Staff<u></u><u></u></span></p>
<p class="MsoNormal"><img width="156" height="40" style="width:1.625in;height:.4166in" id="m_-3307701127870514792Picture_x0020_1" src="cid:image001.jpg@01D3D0D3.949647F0" alt="cid:image002.jpg@01D39374.DEC5A2E0"><span style="font-size:10.0pt;font-family:"Times New Roman",serif;color:#1f497d"><u></u><u></u></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"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1f497d">972-603-1931 (office)<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1f497d">214-926-0622 (mobile)<u></u><u></u></span></p>
<p class="MsoNormal"><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><u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
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