AuthorTopic: Official Off-Topic Thread 2015  (Read 92307 times)

Offline Crow

  • 0011
  • **
  • Posts: 647
  • Karma: +0/-0
  • Technicanimal
    • View Profile

Re: Official Off-Topic Thread 2015

Reply #180 on: March 20, 2015, 04:57:46 pm
Hey, guys, what about the "Good Reads" childboard? It disappeared. ???
Hopefully Cyangmou can tell us what happened.

Merged with the Feature Chest. It's all in there now.
Discord: Ennea#9999

Offline 32

  • 0011
  • **
  • Posts: 535
  • Karma: +1/-0
    • @AngusDoolan
    • http://pixeljoint.com/p/19827.htm
    • View Profile

Re: Official Off-Topic Thread 2015

Reply #181 on: March 23, 2015, 01:41:37 pm
Just found out my graduate film (animated short) is going to Cannes :yay:

Offline PixelPiledriver

  • 0011
  • **
  • Posts: 997
  • Karma: +6/-0
  • Yo!
    • View Profile
    • My Blog

Re: Official Off-Topic Thread 2015

Reply #182 on: March 23, 2015, 08:29:38 pm
Congrats 32!
Post a link to it sometime.
And knowing that it is, we seek what it is... ~ Aristotle, Posterior Analytics, Chapter 1

Offline 32

  • 0011
  • **
  • Posts: 535
  • Karma: +1/-0
    • @AngusDoolan
    • http://pixeljoint.com/p/19827.htm
    • View Profile

Re: Official Off-Topic Thread 2015

Reply #183 on: March 23, 2015, 10:52:32 pm
Thanks PPD ;D

Not online yet due to film festival exclusivity or some such ::) Not really my decision but I imagine we'll put it up eventually, I'll post a link when we do.

Offline surt

  • 0011
  • **
  • Posts: 570
  • Karma: +0/-0
  • Meat by-product
    • not_surt
    • http://pixeljoint.com/p/2254.htm
    • View Profile
    • Uninhabitant

Re: Official Off-Topic Thread 2015

Reply #184 on: April 06, 2015, 12:43:36 am
Anybody know of a way to per-pixel render marching ants that it looks okay on lines of any given angle?
« Last Edit: April 06, 2015, 12:48:55 am by surt »

Offline Ai

  • 0100
  • ***
  • Posts: 1057
  • Karma: +2/-0
  • finti
    • http://pixeljoint.com/pixels/profile.asp?id=1996
    • finticemo
    • View Profile

Re: Official Off-Topic Thread 2015

Reply #185 on: April 06, 2015, 02:39:51 am
Anybody know of a way to per-pixel render marching ants that it looks okay on lines of any given angle?

Probably you need to be a bit more specific. For example, if I was doing this with Cairo, I would simply use cairo_set_dash , then disable antialiasing and render the lines in question. I'd move the ants by cycling the offset parameter. If I needed proper two-color marching, I'd probably draw the line twice, the first with a solid color and the second dashed with the second color.

For the most general/lowlevel case, you should be able to just use bresenham's algorithm and a dash array (eg [0,0, 1, 1] for 2px-long dashes); each new pixel you visit, you take dasharray[curoffset] as the color to plot, then set offset = (offset + 1) modulus 4. The same method of 'walking' the ants as in my Cairo example applies. Pretty simple, the only thing to keep in mind is that you only count whole pixels for purposes of plotting dashes (ie. you treat a 1px 45-degree move as the same distance as a 1px 90-degree move)

This is the algorithm I am currently using (manually) when drawing icons.
Here's what it looks like applied to the mask icon I drew recently:

If displayed on a high resolution screen, longer dashes than this appear to be appropriate, for better visibility.. maybe as long as 8. Of course, on smaller contours, you need to use a smaller dash size to make it read well, so there is probably some compromise involved there -- 4 might work for most situations.

BTW, while I was making this animation I discovered that GIMP 2.9 has an improved Animation Playback plugin: notably, it allows you to zoom the animation 51% -> 300% size, override the layer application mode (combine vs replace), and refresh with any changes you've made in the meantime.
« Last Edit: April 06, 2015, 02:55:42 am by Ai »
If you insist on being pessimistic about your own abilities, consider also being pessimistic about the accuracy of that pessimistic judgement.

Offline surt

  • 0011
  • **
  • Posts: 570
  • Karma: +0/-0
  • Meat by-product
    • not_surt
    • http://pixeljoint.com/p/2254.htm
    • View Profile
    • Uninhabitant

Re: Official Off-Topic Thread 2015

Reply #186 on: April 06, 2015, 04:39:06 am
Prefer to be able to do it in fragment shader so ideally no extra geometry. With the traditional (x+y)%2 diagonals can render as a single colour which is a problem.

Offline Ai

  • 0100
  • ***
  • Posts: 1057
  • Karma: +2/-0
  • finti
    • http://pixeljoint.com/pixels/profile.asp?id=1996
    • finticemo
    • View Profile

Re: Official Off-Topic Thread 2015

Reply #187 on: April 06, 2015, 05:30:13 am
Prefer to be able to do it in fragment shader so ideally no extra geometry. With the traditional (x+y)%2 diagonals can render as a single colour which is a problem.

Yeah, as far as I know there aren't any 2-color patterns that satisfy that criteria (BTW, GIMP at least implements marching-ants via pattern fill, and displays the same general problem. That's why I thought patternfill was something you wanted to avoid). I think that tile/map theory may have even proved that no such pattern is possible.

Of course, a larger pattern is robust against higher slopes, with the caveat that what you get is more 'sparkly' than 'crawly'. 4x4 pattern:

Resulting animation (done by taking the base pattern and offsetting it 1,1 pixel each frame):


Was going by the arbitrary rule of thumb that to handle a slope of 1 in N you need a pattern that is 2N in size. It also seems to be true that the pattern must not have an 'orientation' -- it needs to be something that is symmetrical in both axes and varies continuously along all known diagonal, horizontal, and vertical lines.

Other types of pattern are possible (eg a Bayer matrix), but don't necessarily look crawley.

EDIT: Come to think of it, Plasma fits the criteria I specified . Seems to work pretty well:


A sudoku would also do (but in all likelihood wouldn't look at all like marching ants)

EDIT2: probably the simplest solution, but one I guess you probably can't use, would be to just thicken the lines to 2px.
« Last Edit: April 06, 2015, 11:57:08 am by Ai »
If you insist on being pessimistic about your own abilities, consider also being pessimistic about the accuracy of that pessimistic judgement.

Offline surt

  • 0011
  • **
  • Posts: 570
  • Karma: +0/-0
  • Meat by-product
    • not_surt
    • http://pixeljoint.com/p/2254.htm
    • View Profile
    • Uninhabitant

Re: Official Off-Topic Thread 2015

Reply #188 on: April 12, 2015, 07:28:51 am
Got implicit instancing-based wrapped rendering and painting with shader-based brushes working in my very WIP editor:

Offline PixelPiledriver

  • 0011
  • **
  • Posts: 997
  • Karma: +6/-0
  • Yo!
    • View Profile
    • My Blog

Re: Official Off-Topic Thread 2015

Reply #189 on: April 14, 2015, 09:11:17 am
Looking nice :o
Is that tool open for testing?
And knowing that it is, we seek what it is... ~ Aristotle, Posterior Analytics, Chapter 1