Just pointing out that attempting to solve the real problem should be tried first, before jumping to work-arounds.
If the software converts to pre-multiplied, then there'd be no halo problem and no bleeding necessary, right?
You're right that bleeding won't hurt assets if you're comping, but it will hurt assets if you're not converting to premult and then do texture filtering or mipmapping or blurring.
My concern is with using bleeding is the article's suggestion to use bleeding as a first resort, rather than a last resort (as an artist). It's a hack that totally works in a lot of cases, but it's still a hack. I've watched artists in film and games use random combinations of bleeding, (un)pre-multiply, gamma, and other stuff whenever something goes wrong with matting, and often it's not the right solution. A lot of people are scared of understanding premultiplied alpha - and the technical name isn't doing anyone any favors - and instead of figuring out the right solution they try every combination of hacks until it works. General misunderstanding and superstition about premultiplied alpha is the most common reason I've seen for people using un-premultiply nodes in production.
If the software converts to pre-multiplied, then there'd be no halo problem and no bleeding necessary, right?
You're right that bleeding won't hurt assets if you're comping, but it will hurt assets if you're not converting to premult and then do texture filtering or mipmapping or blurring.
My concern is with using bleeding is the article's suggestion to use bleeding as a first resort, rather than a last resort (as an artist). It's a hack that totally works in a lot of cases, but it's still a hack. I've watched artists in film and games use random combinations of bleeding, (un)pre-multiply, gamma, and other stuff whenever something goes wrong with matting, and often it's not the right solution. A lot of people are scared of understanding premultiplied alpha - and the technical name isn't doing anyone any favors - and instead of figuring out the right solution they try every combination of hacks until it works. General misunderstanding and superstition about premultiplied alpha is the most common reason I've seen for people using un-premultiply nodes in production.