After testing my sample app on many mobile devices (Android and iOS)
and web browsers, I conclude the following observations for reference:
(The tested web site: http://18.104.22.168/apps/demo.html)
All devices work fine.
a. device on Landscape mode:
all devices work fine.
b. device on Portrait mode:
screen mode: error occurred(or unstable) on all iOS devices.
(b) full screen mode: all
devices work fine.
on rendering the OSM base map
Landscape mode get better performance than that on Portrait mode.
stable on mobile device and web browser.
(2) bgltf: unstable on mobile
device, but stable on web browser.