Thread: Motion Blur Questions

  1. #1
    For Narnia! Sentral's Avatar
    Join Date
    May 2005
    Location
    Narnia
    Posts
    719

    Motion Blur Questions

    Ok, since alot of the games today (next gen) are using motion blur, i have some questions on what exactly and how motion blur is achieved. I know a little of what it might be. Does it consist of some type of alpha layer, and then just keep adding alpha layers? I'm not sure how this is achieved. So if anyone knows, please tell me. Note that I don't want specific code since I am no where near that advanced. But just curious.

  2. #2
    Supermassive black hole cboard_member's Avatar
    Join Date
    Jul 2005
    Posts
    1,709
    Quote Originally Posted by Sentral
    Ok, since alot of the games today (next gen) are using motion blur, i have some questions on what exactly and how motion blur is achieved. I know a little of what it might be. Does it consist of some type of alpha layer, and then just keep adding alpha layers? I'm not sure how this is achieved. So if anyone knows, please tell me. Note that I don't want specific code since I am no where near that advanced. But just curious.
    OMGPOSTSTEALER!

    I was going to post something like this because I was wondering yesterday how this is achieved. It adds quite a lot of depth to the atmosphere when done "right", like in CoD2 if you have a mortar land near you and it blows you off your feet, alá the D-Day landing map.
    Good class architecture is not like a Swiss Army Knife; it should be more like a well balanced throwing knife.

    - Mike McShaffry

  3. #3
    Crazy Fool Perspective's Avatar
    Join Date
    Jan 2003
    Location
    Canada
    Posts
    2,640
    Most of the motion blur Ive seen is a post process on the rendered scene. If you want specifics than google it or steal the source for the projectoffset codebase.

  4. #4
    The Right Honourable psychopath's Avatar
    Join Date
    Mar 2004
    Location
    Where circles begin.
    Posts
    1,071
    With shaders:
    Frames are usually stored in a renderable texture, and blended with the current frame.

    Without shaders (OpenGL, not sure about D3D):
    Frames are stored in the accumulation buffer, and blended with current frame.


    And that concludes everything I know about motion blur. ;}
    M.Eng Computer Engineering Candidate
    B.Sc Computer Science

    Robotics and graphics enthusiast.

  5. #5
    Registered User VirtualAce's Avatar
    Join Date
    Aug 2001
    Posts
    9,607
    Accumulation buffers are used as psychopath said. It is the same process as the feedback in your average Windows MP3 player. A lot of post-processing, a lot of GPU tricks, a lot of headache, and if you ask me a lot of effort to give your gamer's seizures.

  6. #6
    The Right Honourable psychopath's Avatar
    Join Date
    Mar 2004
    Location
    Where circles begin.
    Posts
    1,071
    Yeah, it's generally not a good idea to use motion bluring excessively. Usually in cinematics or cutscenes it can add a nice touch, or to simulate dizzyness. For example, in Gran Turismo 4, when you switch the camera view to in-car and you crash, motion blur is used to swirl and distort the screen, to loosely simulate what the driver sees. There are probably other scenarios where you would use MB, but I can think of any more at the moment.
    M.Eng Computer Engineering Candidate
    B.Sc Computer Science

    Robotics and graphics enthusiast.

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. questions....so many questions about random numbers....
    By face_master in forum C++ Programming
    Replies: 2
    Last Post: 07-30-2009, 08:47 AM
  2. A very long list of questions... maybe to long...
    By Ravens'sWrath in forum C Programming
    Replies: 16
    Last Post: 05-16-2007, 05:36 AM
  3. Several Questions, main one is about protected memory
    By Tron 9000 in forum C Programming
    Replies: 3
    Last Post: 06-02-2005, 07:42 AM
  4. Trivial questions - what to do?
    By Aerie in forum A Brief History of Cprogramming.com
    Replies: 23
    Last Post: 12-26-2004, 09:44 AM
  5. questions questions questions.....
    By mfc2themax in forum A Brief History of Cprogramming.com
    Replies: 1
    Last Post: 08-14-2001, 07:22 AM