Hey guys, I'm new to Unity3D (almost a day now) and am working with making sort of an adventure game for a college project. I am facing the following issues. I made a terrain with mountains and trees etc. However, it turn out that I am still able to walk through the trees and the mountains. I tried making the terrain a rigid body, however this led to the whole terrain falling down (with gravity active) or my player character suddenly flying up. Can someone please help me out with this. On a side node, I went to eh Unity fps tutorial and made a projectile gun. I want my projectiles to disappear after they stop moving (They are like rocks being thrown). I used the destroy object using ActiveVelocity and Speed. However, I am still unable to get them to disappear. Please help me out with this, I really need to get this work done by next week. Thanks!