1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Expert Help: Does this physics simulation appear realistic to you?

  1. Sep 28, 2009 #1

    This is a game called Gran Turismo 5, which is still under development.

    10 seconds into the clip, the car drives through some plastic barriers. I find that the barriers are simulated very unrealistically given their reaction to the car, as the force vector modeling appears to be completely off. However, more importantly, their decent to the ground seems very peculiar.

    I imagine there is still a lot of modeling left to be done.

    However, could some physics experts please weight in.

    Last edited by a moderator: Sep 25, 2014
  2. jcsd
  3. Sep 30, 2009 #2
    No, physics cannot be simulated properly in real time at the moment so they simplify a ton. A whole ton. But perfect physics is probably not what you want to go for in a game like that unless you want to die every time you car clips a wall anyway.

    The reason they slowly descend to the ground is because games nowadays use what is called a linear solver that solves physics equations in one or two dimensions at a time, and the constraints placed on the solutions (to prevent wild stuff from happening) prevent the solver from moving object too far in one pass, and multiple passes are needed for accuracy and to move an object far enough to seem realistic. When the game is drawing more stuff the solver runs less to preserve FPS and this make the object fall more slowly.

    EDIT: Not that I'm an expert but does something like this really need expert help? Srsly?
  4. Sep 30, 2009 #3
    What looks wrong is that those blocks are just sliding over the car and the asphalt while they should make a lot of holes and thus not slide.

    The descent of the objects is just fine, you are just speed blind due to the car moving so fast.
  5. Sep 30, 2009 #4
    It's a driving game... don't crash. Then the crash physics are irrelevent.

    Why waste processing power on making a perfectly realisitc crash, when thats not the point of the game?
  6. Sep 30, 2009 #5
    Yeah, I didn't even watch that far honestly... having now done so, it's fine (even though the video runs at like 2fps on the PC I'm on ATM so it's hard to make out anything).

    But yeah, if there ever is a problem such as objects going through walls, slowing down etc. it's the solver getting you. They are rough approximations with speed in mind.

    EDIT: Aren't those blocks usually filled with water? That would suck to hit at high speed, esp a bunch of them.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook