Shawn Hargreaves Blog
A common side effect of developing new technology is the invention of new terminology. At its best, this can be both fun and useful, providing a concise shorthand for what would otherwise be awkward or ambiguous concepts. These shorthands are often unique to a company or project, and different teams sometimes invent conflicting words for the same idea (for instance, when I was working on MotoGP we used "faceme" to refer to what in XNA land would be called a "billboard" sprite).
I thought I would share a few of my favorite such words from times gone by. Who knows, maybe you will find these useful enough to restore them to their rightful place in everyday use? :-)
Definition: An artifact at the edge of an alpha cutout texture, where incorrect pixel colors are visible due to filtering or antialiasing problems.
Usage: "I need to clean up this texture to get rid of the parakeets."
Etymology: Long time ago, I was working on a Playstation 2 game where we used magenta colorkey to create alpha cutout tree textures. A common problem was that if the artists were not careful while editing these textures in Photoshop, they could end up with stray antialiased pixels that were nearly but not quite magenta. Such pixels would not be recognized by the colorkey operation, leaving us with pink dots around the edge of the tree.
One day the technical director was looking at an early build of the game, noticed one of these pink pixels nestling among the green, and asked "why are there parakeets in the trees?"
The term stuck, and was soon generalized to include images other than trees, colors other than magenta, and edge artifacts caused by runtime filtering or antialiasing as well as color keying.
I feel like im getting those now in my xna game. Are there any tips too get rid of them?
Ryan: if they come from runtime filtering, premultiplied alpha will fix them (www.talula.demon.co.uk/blogindex.html)
If they come from incorrect color key values in your source artwork, you need to fix it in that source artwork. Either just make sure all your color key markers are exactly the right color, or change to use a proper alpha channel instead of colorkey.
You need to wear alpha glasses while authoring your textures...
They ARE Faceme's and ALWAYS will be...billboards indeed !!!
From a friend:
"pissing squirrels" - color shift due to AO
From a winter/snow outdoors game, with strong orange sunlight and strong blue ambient/backlight; when some kind of ambient occlusion hack occluded the space under the trees in the snowy forest, by contrast it looked yellowish; hypothesis that the squirrels had pissed from the trees.