How does RC define Yaw Pitch Roll?

Hi.

I wonder how does RC define YPR pose and export them. When I export pose to CSV and import them into a 3rd party software, pix4d and contextcapture for example, it's totally messed up. pose is wrong except XYZ position.

Here is my export settings:

<format mask="*.csv" desc="Comma separated, Name, X, Y, Z, Yaw, Pitch, Roll" writer="cvs">
<body EulerFormat="zyx">#cameras $(cameraCount)
#name,x,y,z,yaw,pitch,roll
$ExportCameras($(imageName)$(imageExt),$(x),$(y),$(z),$(yaw),$(pitch),$(roll)
)</body>
</format>

please shed some light on this, thanks