Seems to animate the gameplay camera zoom.
Eg. _ANIMATE_GAMEPLAY_CAM_ZOOM(1f, 1000f);
will animate the camera zooming in from 1000 meters away.
Game scripts use it like this:
// Setting this to 1 prevents V key from changing zoom
PLAYER::SET_PLAYER_FORCED_ZOOM(PLAYER::PLAYER_ID(), 1);
// These restrict how far you can move cam up/down left/right
CAM::_CLAMP_GAMEPLAY_CAM_YAW(-20f, 50f);
CAM::_CLAMP_GAMEPLAY_CAM_PITCH(-60f, 0f);
CAM::_ANIMATE_GAMEPLAY_CAM_ZOOM(1f, 1f);