Hi, I am working on decomposing the world matrix of a mesh, I need it in order to keep rotation, scale and position of a mesh in world space (because these parameters are relative to the parent) if you import it without importing its parents. By testing different codes to decompose the matrix and to transform it into a quaternion, I notice that when you create a BABYLON.quaternion.RotationYawPitchRoll(yaw, pitch, roll) and you call the toEulerAngles() method on this quaternion, it does not return the passed yaw, pitch and roll. I wonder if this behavior is normal ? if yes can you explain me why ? I made a JsFiddle to explain my question. http://jsfiddle.net/Gc7n8/1/ Please look at the console line to see the log.