Pan-tilt Platform control in HITL simulation

I am trying to do a HITL simulation using either jMAVSim or GAZEBO. I am working with the latest firmware version of PX4 and QGC. After following the steps explained on the PX4 website, I launch the simulation via JMAVsim.
I want to add Pan-tilt Platform control into HITL simulation and realize simulation of landing system and simulation of visual guided flight with camera. Does anyone have an idea?