Hi All Has anyone else noticed that mesh colliders can only act as triggers if they are marked as 'Convex'? This is opposite to previous behavior, and must be a recent change - the interface for the mesh collider has also changed and this isn't yet reflected in the help file (still show the old interface). Can anyone from Unity chime in with any additional information on this? This is actually a huge issue for me - I produce large scale engineering visualisations and our whole layer system is built around triggers - when a layer is switched off, all the mesh colliders become triggers so that the various raycasting functions and flying cameras don't bounce off hidden objects. With the new system, you must make Unity draw a low detail convex boundary around the mesh so the collider no longer represents the physical dimensions of the mesh, rendering it useless for my purpose. The system that I use was devised after much trial and error - enabling and disabling gameobjects was taking too long at runtime, as was enabling and disabling the collider itself, so the trigger solution was both easy on performance, simple to implement and works exactly as intended. Is there any reason for this change? Can it be hacked somehow in code? I'm in a bit of a panic right now, because I'm 90% finished porting my system to Unity 5 and this is a massive snag. I'm sure I am not the only one that is going to be affected by this - I daresay that a lot of people who use Unity for non-gaming related purposes use triggers in a similar fashion. Thanks!