this is the BI side of things (I am still using BI4):
goto the camera you would like to use as a virtual motion sensor, camera properties, alerts, choose the profile you want to edit, in the actions section choose "run a program or execute a script", configure, on the new window fill in the path to your curl.exe and this
Code:
curl --header "Content-Type: text/plain" --request PUT --data "ON" http://192.168.2.121:8080/rest/items/Motion_Outside_CamPorch/state
under "run file again when trigger is reset"
Code:
curl --header "Content-Type: text/plain" --request PUT --data "OFF" http://192.168.2.121:8080/rest/items/Motion_Outside_CamPorch/state
The 2 curl commands will most certainly have to be changed to work with your smart things setup.
Basically what it does is sending a http command to the url of your HA hub telling it turn the virtual switch on/off.
In the curl command above "Motion_Outside_CamPorch" is the name of my virtual switch. You will have to figure out how that works for Smart Things, I am sorry but I can't help in that respect.
I don't think you will need IFTTT if you are able to find the http command to flip your virtual switch. Benefit is all the data sent stays on you LAN, no privacy issues and super fast!