Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
The read-only inlineVerticalFieldOfView property of the XRRenderState interface returns the default vertical field of view for "inline" sessions and null for all immersive sessions.
A Number for "inline" sessions, which represents the default field of view, and null for immersive sessions.