1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Aliasing and Filtering explained

Discussion in 'Article Discussion' started by WilHarris, 4 Jul 2005.

  1. WilHarris

    WilHarris Just another nobody Moderator

    Joined:
    16 Jun 2001
    Posts:
    2,679
    Likes Received:
    2
  2. Kameleon

    Kameleon is watching you...

    Joined:
    29 Apr 2003
    Posts:
    3,500
    Likes Received:
    8
    Great job, Wil. Enough detail to understand what's going on without being just too complicated for the mortal man to comprehend (Sorry Tim :D) - I'll definitely be showing this to people rather than trying to explain myself :hip:
     
  3. mrplow

    mrplow obey the fist!!

    Joined:
    5 Sep 2001
    Posts:
    2,563
    Likes Received:
    23
    Nice, but am I supposed to be able to see something in this shot?

    [​IMG]

    It's a bit on the dark side! :eek:
     
  4. Rys

    Rys What's a Dremel?

    Joined:
    21 Sep 2004
    Posts:
    6
    Likes Received:
    0
    Pretty good stuff :D The basics explained without going too overboard. A good read while I have a tea-break, cheers!
     
  5. Hamish

    Hamish What's a Dremel?

    Joined:
    25 Nov 2002
    Posts:
    3,649
    Likes Received:
    4
    lol thats what i was thinking, what bricks? :p

    also those comparison screenies would probably work better if they were a bit bigger, had to zoom in to see the jaggies and nojaggies properly ;)
     
  6. Shadow_101

    Shadow_101 Minimodder

    Joined:
    12 Feb 2004
    Posts:
    1,117
    Likes Received:
    5
    Excellent Read, it’s certainly helped me understand AA an AF better.

    Thought the comparison screenshots where fine though, perhaps you guys need to tweak your monitor settings :hehe:
     
  7. yodasarmpit

    yodasarmpit Modder

    Joined:
    27 May 2002
    Posts:
    11,393
    Likes Received:
    226
    Very good read, one of the best articles yet.
    Explained everything in a way I could understand.
     
  8. Krikkit

    Krikkit All glory to the hypnotoad! Super Moderator

    Joined:
    21 Jan 2003
    Posts:
    23,709
    Likes Received:
    486
    Very good article, i don't agree about the pictures though - the bricks example worked really well for me! :)
     
  9. Hamish

    Hamish What's a Dremel?

    Joined:
    25 Nov 2002
    Posts:
    3,649
    Likes Received:
    4
    oh ok, i can see the bricks on this monitor, secondary monitor is set too dark :eek:
     
  10. DigitalX

    DigitalX What's a Dremel?

    Joined:
    26 May 2004
    Posts:
    17
    Likes Received:
    0
    Hmmp.. JPG? Horrible quality... why dont you use png or gif.. much smaller and better quality with pic that have only a few colors in it.
    [​IMG]

    Good job. :thumb:
     
  11. ralph.pickering

    ralph.pickering What's a Dremel?

    Joined:
    6 Apr 2005
    Posts:
    346
    Likes Received:
    0
    I thought the same, but after I tweaked the gamma and contrast in my display settings I could see it OK.

    Good article, BTW...
     
  12. RotoSequence

    RotoSequence Lazy Lurker

    Joined:
    6 Jan 2004
    Posts:
    4,588
    Likes Received:
    7
    I think most of us can agree that a brighter spot would have made a better example in the dark photo. But, either way, excellent article - you've made AA and AF easy to understand :thumb:
     
    Last edited: 4 Jul 2005
  13. RTT

    RTT #parp

    Joined:
    12 Mar 2001
    Posts:
    14,120
    Likes Received:
    74
    Fantastic article :)
     
  14. Tim S

    Tim S OG

    Joined:
    8 Nov 2001
    Posts:
    18,882
    Likes Received:
    89
    I didn't write it, but I had an input. :)
     
  15. RotoSequence

    RotoSequence Lazy Lurker

    Joined:
    6 Jan 2004
    Posts:
    4,588
    Likes Received:
    7
    Oops :duh:
     
  16. Guest-16

    Guest-16 Guest

    Indeed! /buttkiss :blush:
     
  17. cpemma

    cpemma Ecky thump

    Joined:
    27 Nov 2001
    Posts:
    12,328
    Likes Received:
    55
    Well, it shows my monitor's set up right, unlike some. :p

    Perhaps links to some freeware aids should be added to the article? :hehe: :hehe: :hehe:

    I understood all that and my head doesn't hurt too much, :thumb:
     
  18. Stephen Brooks

    Stephen Brooks What's a Dremel?

    Joined:
    24 Apr 2005
    Posts:
    40
    Likes Received:
    0
    I'm pretty sure rotated grid 4xAA is _not_ rotated by 45 degrees... I think something more like 26.565 degrees would work better as then the four points have X and Y-ordinates regularly spaced along each axis, so for near-vertical and horizontal lines (where aliasing is arguably worst) it is of the best quality you can do.

    OTOH NVidia and ATI might have decided to use 45 degrees for some perverse reason I am too stupid to comprehend... Or maybe I should patent the angle "26.565 degrees" and sell it to them :D

    [edit] Found an in depth article on this http://www.3dcenter.org/artikel/multisampling_anti-aliasing/index6_e.php with some pictures:
    [​IMG]
    [​IMG]
     
    Last edited: 5 Jul 2005
  19. drb

    drb What's a Dremel?

    Joined:
    5 Jul 2005
    Posts:
    1
    Likes Received:
    0
    An example of a difference between ATI and Nvidia is the fact that ATI implement gamma-corrected AA on all their 9700+ cards, a technique which samples alpha particles inside triangles as well as gamma particles on the outside of triangles. This is only implemented by Nvidia on the 7800 GTX.

    Gamma particles? Is this some sort of inside joke?

    I think you have perhaps simplified too much ...

    Multisampling does not require samples to be shared between pixels. Its an approach some vendors use to try to get better image quality.

    It's misleading to say mipmaps are lower-quality distance textures. They are multi-resolution texture image sets (pyramids) used to approximately match the variable resolutions needed for different object scalings by choosing the closest matching (or pair of matching) images. You probably meant that, but it's not what the article is saying ...
     
  20. Zidane

    Zidane What's a Dremel?

    Joined:
    27 Apr 2004
    Posts:
    688
    Likes Received:
    0
    very nice article. explains without confusing. gives enough information to inform, without being too technical, and gives the reader many avenues to explore if they want to know more.
     
Tags: Add Tags

Share This Page