@feistykittykat I have encountered the same issue regarding the convention today, and I was able to verify that the actual order in which the rotation is applied is indeed in the 2-1-3 (Y-X-Z) sequence, irrespective of the confusing yaw/pitch/roll nomenclature. I think at least specifying that the yaw/pitch/roll are specified in the camera coordinates would make it clearer, as X,Y,Z axes in robotics convention becomes -Z,-Y,X in (OpenGL) camera coordinates which results in the mixed terminology/axes specifications. Snippet for testing: bool IsQuaternionClose(const QQuaternion& lhs, const QQuaternion& rhs, const float tol = 1e-6) { QVector3D axis{}; float angle{0}; (lhs * rhs.inverted()).getAxisAndAngle(&axis, &angle); return angle < tol; } void TestQuaternion(const float ax, const float ay, const float az) { const QQuaternion rx = QQuaternion::fromEulerAngles(ax, 0, 0); const QQuaternion rx2 = QQuaternion::fromAxisAndAngle(1.0f, 0.0f, 0.0f, ax); assert(IsQuaternionClose(rx, rx2)); const QQuaternion ry = QQuaternion::fromEulerAngles(0, ay, 0); const QQuaternion ry2 = QQuaternion::fromAxisAndAngle(0.0f, 1.0f, 0.0f, ay); assert(IsQuaternionClose(ry, ry2)); const QQuaternion rz = QQuaternion::fromEulerAngles(0, 0, az); const QQuaternion rz2 = QQuaternion::fromAxisAndAngle(0.0f, 0.0f, 1.0f, az); assert(IsQuaternionClose(rz, rz2)); const QQuaternion ryxz = QQuaternion::fromEulerAngles(ax, ay, az); assert(IsQuaternionClose(ry * rx * rz, ryxz)); } Found the bug report (that loops back to this thread): https://bugreports.qt.io/browse/QTBUG-78548?jql=text ~ "qquaternion euler" Hopefully this will be addressed soon, as it is quite a confusing behavior.