Create multicam clip from multiple Camera3D tools?

I've got a multicam clip into which I want to place some particle effects. I want the camera angles on the particle effects to match the camera angles in the multicam clip. In my comp, I've set up 3D cameras to mimic the placement of the physical cameras and I'm wondering whether there's a way to go straight from this to a multicam clip or if I need to do it manually by rendering each camera angle separately and then combining them into a multicam clip.

Thanks!