A few suggestions or comments on this. 1.  Grenades should not be blocked by a doorway that I'm just behind (Ouch). 2.  Grenades should be able to clear low obstacles that I'm near and only be blocked by low obstacles near the landing target.  High obstacles should always block.  Not sure how to make a rule about fences though.  A high fence should be clearable if near the apex of the trajectory I suppose, but might be hard to implement. 3. Maybe could be able to throw a grenade t