camera setting of the FfxFsr2DispatchDescription

[butters dousha]

Thanks for your great work!
I am working on off-screen rendering of FSR2, I got a series of images and Gbuffers I captured from other render engine,now I want to feed them to FSR2，and wish to get results with higher resolution.
Now I am walking to the ffxFsr2ContextDispatch , in the FfxFsr2DispatchDescription,
cameraNear,cameraFar and cameraFovAngleVertical confused me..
I notice that near and far are not used through the process...but I found something about the FovAngle

const FfxFloat32 Ksep = 1.37e-05f;
    FfxFloat32 fRequiredDepthSeparation = Ksep * fDepthThreshold * TanHalfFoV() * fHalfViewportWidth;
    FfxFloat32 fDepthDiff = fCurrentDepthViewSpace - fPrevNearestDepthViewSpace;

    FfxFloat32 fDepthClipFactor = (fDepthDiff > 0) ? ffxSaturate(fRequiredDepthSeparation / fDepthDiff) : 1.0f;

what should be set under my circumstance? maybe 90° for fov？