• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
radioteeth

detecting 3D array configurations

2 posts in this topic

 Hi all.

 

 I've been wracking my brain trying to find a simple solution to this problem, but everything I come up with seems overly complicated.

 

 I have a 2x2x2 array where each cell can be on or off. This yields 256 possible states for the array. The problem I'm having is finding a way to detect a specific set of configurations - including their multiple possible orientations AND mirrored versions - without having to resort to creating a look up table. There are no requirements that disallow a simple look up table to determine which configuration the cells are in, except that I'd rather have a solution that could be expanded to larger arrays.

 

 The closest to a solution I've devised thus far involves counting how many adjacent cells (eg: 0, 0, 0 - 1, 0, 0), diagonal cells (0, 0, 0 - 1, 1, 0) and opposing cells (0, 0, 0 - 1, 1, 1) there are, and comparing those numbers to the numbers involved in each configuration. This overcomes checking for various orientations and mirrored versions of specific cell configurations, but requires that cells are all manually inspected and compared against other cells, which seems unavoidable, but I keep getting this nagging feeling that I could somehow represent the array in a way that allows for an XOR or two against template configurations to count these relationships more quickly.

 

 This is a very abstract problem without a clear and concise method of solving it. I've tried looking at it from many different angles and have exhausted myself for the time being. I'm merely seeking any insight anybody may have about an effective and efficient solution beyond what I have come up with on my own so far.

 

 Thanks.

0

Share this post


Link to post
Share on other sites

Can you just flatten the array?  Then you basically have a bitfield or an integer, and just compare the integers.  EDIT:  Whoops, that doesn't count mirrored versions.  Though you could compute that as well, I think, by flipping those sections in integer. and testing for equality.

 

EDIT2:  For rotation, I think you might be able to get away by rotating the bitfield.  IE 10010010, rotated right by 1 is 01001001.  Might be worthwhile.

 

EDIT3:  Are mirrors a derivative of rotations?  They are at least in the 2D cube case.  In which case, I believe you basically just loop and rotate one of the bitfields through 8 times to see if it matches the other?  

Edited by ferrous
0

Share this post


Link to post
Share on other sites
This is roughly a set/subset problem. Take the shape you're trying to draw. This is a 3D array itself. Compare this array to the one you're testing. Take as input a matrix that maps coordinates. You then check the source array with matrices [1,1,1], [-1,1,1] (mirrored X), [1,-1,1], etc. If the template array is able to be smaller than the checked array (say the shape is a 1x2x2 shape) then first "trim" the input array to its contents. That is, if I only fill up the left half of a 2x2x2 array than I only have a 1x2x2 array. If the sizes are different after trimming, the shapes cannot possibly match and there's no further work to be done.
 
array3d trim (array3d input)
  min = minimum occupied cell coordinates (input)
  max = maximum occupied cell coordinates (input)
  size = max - min
  return new array3d(size, input[min to max])
end

bool match_permutation (array3d test_in, array3d test_for, matrix3d transform)
  if dimensions of test_in != transform * dimensions of test_for
    return false
  end

  for each x in test_in
    for each y in test_in
      for each z in test_in
        if test_for[x,y,z] != test_for[transform * (x,y,z)]
          return false
        end
      end
    end
  end

  return true
end

bool contains(array3d test_in, array3d test_for)
  trimmed = trim(test_in)
  if match_permutation(test_in, test_for, identity)
    return true
  end
  if match_permutation(test_in, test_for, [-1, 1, 1])
    return true
  end
  ... also [1, -1, 1] and [1, 1, -1] and [-1, -1, 1] and [1, -1, -1] and [-1, 1, -1] and [-1, -1, -1] ...
  return false
end
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0