Applying collision bitmasks to ray sensors

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Is there any way to apply a collision bit mask to a ray or GPU ray sensor such that it will only detect collision models with corresponding masks? I am trying to create models with "glass" walls where certain sensors like lidars may pass through and hit walls beyond, but can also still be collided into or detected by other sensors like sonars. If there isn't a way to apply the bit masks, is there other options for creating a similar effect? My current solution is to ignore readings below a certain laser_retro value, but this doesn't allow for the detection of objects past the "glass" wall. I am using Gazebo 7.

Thanks in advance for any help.