   Falling Collision Handling For Game
  I have a question for handling the falling part of collisions in my 3D game I am coding.When using falling collisions in a 3D environment, ray tracing is expensive if used a lot, so I am wondering how is the best way to handle a character (or any object) falling in 3D space, like a character walking around or jumping down from a ledge, because even for a character walking, it's got to detect the ground (and if any slopes), so what would be the best way to handle this, or how has other people handled this before?Any help would be appreciated, thanks in advance.   
  I have a theory which I am currently testing. It allows characters to go up and down stairs and what not.Raycasting is not a bad idea. Assuming you only do it once per character, it won't be too expensive. (n.b. you said raytracing which is slightly different). Or, you could use the bounding volume instead.Cast a ray starting slightly above the bottom point of the character and ending slightly below the bottm point of the character. The distance between the start of the ray and the bottom of the character is the maximum step the character can climb without needing to jump. (or, in my case, test what happens when the bounding volume moves from slightly above to slightly below)If a collision does not occur, then I add 9.81 / time step to the downward velocity of the character. If a collision does occur, either take the point of intersection or, if you can't calculate it, use a binary search.Thats the algorithm I'm currently implementing. I'll post back here if it works   