问题
I understand the following.
1) ViewPort: It is like a window through which one can see the outside world. Basically, it is a 2D plane on which 3D objects gets projected.
2) Field Of View (FOV): FOV is a cone projection from the eye pupil or virtual camera. One can see everything inside that cone projection without turning the head.
Monocular FOV is what a single eye can see
Binocular FOV is what both eyes put together can see clearly
Peripheral FOV is the region outside the binocular FOV but within monocular FOV.
My question is,
1) What is ViewPort and FOV in a virtual reality (VR) Headset device? What is the difference between them in that context?
回答1:
ViewPort is what you describe. It's usually defined as bounds. Between 0.0 and 1.0 for both width and height, where 0.0 is the left-most edge of the screen. Less intuitively 0.0 is at the bottom of the screen (I guess this might vary between systems). Sometimes it's defined in screen pixels instead. Also, rather than absolute bounds, second parameters may be defined as extent instead.
Example:
Left viewport definition, bounds (0.0, 0.0, 0.5, 1.0) Means going from left/bottom corner, to center/top.
Right viewport definition, bounds (0.5, 0.0, 1.0, 1.0)
Means going from center/bottom, to right/top.
Right viewport definition, extent (0.5, 0.0, 0.5, 1.0)
Going from center/bottom, and extends half a screen horizontally, full screen vertically.
FOV is usually mentioned as the total field the user can see (counting both viewports in the case of VR). It's usually measured as an angle in degrees.
来源：https://stackoverflow.com/questions/39971537/what-is-the-difference-between-viewport-and-field-of-view-fov-in-vr-devices