<html><head><meta http-equiv="content-type" content="text/html; charset=us-ascii"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">I've seen that the email thread starting with the minutes of the last Blender-X3D support call had a subthread about the orientation conventions that glTF, Blender, and X3D use.<div><br></div><div>I recommend Michalis' answer at <a href="https://web3d.org/pipermail/x3d-public_web3d.org/2024-November/020882.html">https://web3d.org/pipermail/x3d-public_web3d.org/2024-November/020882.html</a>.</div><div><br></div><div>One confusing aspect is that not only do Blender and glTF disagree about which axis is forward, they disagree about what the word "forward" means.</div><div><br></div><div>For Blender, the word "forward" refers to the axis that the viewer is looking along when they are viewing the front of the model. </div><div>The viewer is translated from the model in the -Y direction, and they are looking in the +Y direction. That, +Y, is Blender "forward"</div><div><br></div><div>glTF defined "forward" by the model.Looking at the first sentence of the of section 3.4 of the glTF specification. <a href="https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#coordinate-system-and-units">https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#coordinate-system-and-units</a>, </div><div><span style="font-family: -webkit-standard; font-size: medium;"><br></span></div><blockquote type="cite"><div><span style="font-family: -webkit-standard; font-size: medium;">glTF uses a right-handed coordinate system. glTF defines +Y as up, +Z as forward, and -X as right; the front of a glTF asset faces +Z.</span></div></blockquote><div><br></div><div><br></div><div>glTF says the "forward" refers to the direction the asset, a.k.a. model is facing and the spec shows this example picture . In Blender terminology this model is oriented "-Z forward"</div><div><br></div><div><br></div><div><br></div><div><img src="cid:5E260929-79CD-4D28-80BE-AAF6C1474AAA" alt="boombox.png"></div><div><br></div><div>The X3D standard has the same orientation convention as glTF, by virtue of the X3D default placement of the Viewpoint at a Z=+10 position and looking in the -Z direction. That is why in Blender terminology the X3D convention should be considered -Z forward. The code in the Blender extensions server was changed to this default for X3D import and export on Nov 4 2024 and this default is in release 2.4.0 of this Blender extension.</div><div><br></div><div>Vince Marchetti</div><div><br></div><div><br></div><div><br></div></body></html>