Question about default source camera and the render camera setting.

[otakuxiang]

I noticed that only when source camera following the setting that azimuth=270, elevation=0, the triplane would render the same image as input under input pose.
My question is, when I have a image under pose $T_0$, and I want to render a image under pose $T_1$. How should I adjust the render camera?
I've tried to get the ref_pose $T_2 = T_dT_0^{-1}$ where $T_d$ is the default pose, and convert $T_1$ with ref_pose, but it totally gives an wrong image.
In my setting, the camera distance is 1.5, and the input azimuth is 2.3562(rad), elevation is -0.1317(rad)
the target azimuth is 0, elevation is 0.52359878.
The input image

And the target image

Both two image are rendered by blender.